EPA-600/3-77-017
February 1977
Ecological Research Series
PROCEEDINGS OF
MOiMAST
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into five series. These five broad
categories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are-
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ECOLOGICAL RESEARCH series. This series
describes research on the effects of pollution on humans, plant and animal
species, and materials. Problems are assessed for their long- and short-term
influences. Investigations include formation, transport, and pathway studies to
determine the fate of pollutants and their effects. This work provides the technical
basis for setting standards to minimize undesirable changes in living organisms
in the aquatic, terrestrial, and atmospheric environments.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161
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EPA-600/3-77-017
February 1977
PROCEEDINGS OF SYMPOSIUM
ON
1975 NORTHEAST OXIDANT TRANSPORT STUDY
Research Triangle Park, North Carolina
January 20-21, 1976
Edited by
Joseph J. Bufalirri
William A. Lonneman
Environmental Sciences Research Laboratory
- Research Triangle Park, North Carolina 27711
Environmental Sciences Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
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DISCLAIMER
This report has been reviewed by the Environmental Sciences Research Labora-
tory, U.S. Environmental Protection Agency, and approved for publication. Mention
of trade names or commercial products does not constitute endorsement or recommen-
dation for use.
11
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ABSTRACT
The preliminary results of the 1975 Northeast Oxidant Transport Study were present-
ed by the participants of the study at a symposium held at the Environmental Research
Center in Research Triangle Park, NC, on January 20-21, 1976. The participants in-
cluded the Environmental Protection Agency's Environmental Sciences Research Lab-
oratory, EPA Region I, EPA Las Vegas, Battelle Columbus, Washington State Univer-
sity, Interstate Sanitation Commission, New York State Department of Environmental
Conservation, and the University of North Carolina. Discussed were preliminary re-
sults of ozone measurements collected during a study conducted to investigate trans-
port phenomena in the Northeastern United States. The study was undertaken to in-
vestigate the extent and importance of transport in this densely populated area. The
ultimate purpose of the study was to provide the necessary information needed to
determine the suitability of present control strategy.
111
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CONTENTS
ABSTRACT iii
FIGURES vi
TABLES . :xii
1 . INTRODUCTION - Joseph J . Bufalini and William A . Lonneman .... 1
2 . OPENING REMARKS - Joseph J . Bufalini ............... 4
3 . OZONE AND OTHER POLLUTANTS MEASURED BY WASHINGTON
STATE UNIVERSITY DURING THE 1975 NORTHEAST OXIDANT
TRANSPORT STUDY - H . Westberg ................ 6
4 . OZONE AND OTHER POLLUTANTS MEASURED BY BATTELLE
DURING THE 1975 NORTHEAST OXIDANT TRANSPORT
STUDY - Chester W . Spicer ................... 17
5. METEOROLOGICAL DATA FOR THE 1975 NORTHEAST OXIDANT
TRANSPORT STUDY - Karl . F. Zeller ......... ..... 29
6 . OZONE AND OTHER POLLUTANTS MEASURED BY THE
ENVIRONMENTAL PROTECTION AGENCY , LAS VEGAS ,
DURING THE 1975 NORTHEAST OXIDANT TRANSPORT STUDY -
George W . Siple ......................... 35
7 . PRELIMINARY RESULTS~OF ^^
POLLUTANT MEASUREMENTS TAKEN DURING THE
1975 NORTHEAST OXIDANT TRANSPORT STUDY -
William A . Lonneman et al . .................... 40
8. TRENDS IN OZONE LEVELS IN SOUTHERN NEW ENGLAND
FOR 1975 - Donna D. Morris and Arnold L. Leriche 54
9. AERIAL INVESTIGATION OF PHOTOCHEMICAL OXIDANTS
OVER THE NORTHEAST - George T. Wolff et al 70
10. AIR QUALITY ABOVE THE MORNING SURFACE INVERSION
AND ITS EFFECT ON URBAN OZONE CONCENTRATION -
Robert A. Whitby 87
11. OZONE FIELD AUDITS~FOR~1975 NORTHEAST OXIDANT
TRANSPORT STUDY - Thomas M. Spitter 98
12. SIMULATION OF OXIDANT AND PRECURSOR TRANSPORT
IN A SMOG CHAMBER - Lyman A. Ripperton 109
13. OZONE TRANSPORTED TO NANTUCKET, MA,
OCTOBER 1975 - Thomas J\ Kelleher, Jr., et al 123
ATTENDANCE LIST 128
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FIGURES
Number Page
3-1 Geographic Location of Special Study Groups for 1975 Northeast
Oxidant Transport Study 7
3-2 Location of Groton Study Site 7
3-3 Aircraft Flight Pattern for Boston Loop 8
3-4 Aircraft Flight Pattern for South Boston Flights 8
3-5 Typical Southwestern Flight Pattern from Groton 8
3-6 Typical Southeastern Flight Pattern from Groton 8
3-7 Ozone Results (in ppb) for Airflight Downwind of New York -
New Jersey Area During Afternoon Hours of July 22, 1975 10
3-8 Vertical Profiles of Ozone and Temperature over Point g 10
3-9 Vertical Profiles of Ozone and Temperature over Point d 11
3-10 Vertical Profiles of Ozone and Temperature Between
Points d and g 11
3-11 Diurnal Ozone Patterns at Groton Ground Site During July
17-20, 1975 12
3-12 Diurnal Profiles for Ozone and Freon-11 Groton Ground Site
During July 17-20, 1975 12
3-13 Vertical Profiles for Ozone and Temperature over Groton During
Afternoon of July 17-20, 1975 13
3-14 Ozone Results (in ppb) for Morning Flight of August 3, 1975 .... 14
3-15 Expanded View of Southwest Portion of Arc for
August 3, 1975 Flight 14
3-16 Diurnal Patterns of Ozone (in ppb) at Groton Ground Site During
August 9-14, 1975 15
3-17 Expanded Views of Diurnal Ozone Patterns at Groton Ground Site
for August 10 and 13, 1975 15
3-18 Ozone Results (in ppb) for Aircraft Flight During Late Afternoon
Hours of August 10, 1975 16
3-19 Vertical Profiles for Ozone and Temperature Near Groton During
Afternoon Hours of August 10, 1975 16
4-1 Topographic Map of 1975 Oxidant Transport Study Area 17
4-2 Composite Profiles for Meteorological Measurements Made at the
Simsbury Site During the 39-Day Study Period 19
4-3 Composite Profiles for the Ozone and Nitrogen Oxides at the
Simsbury Site for the 39-Day Study Period 19
VI
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Number Page
4-4 Composite Profiles for Methane, Total Methane Hydrocarbon, and
Carbon Monoxide at Simsbury Site for the 39-Day Period 20
4-5 Composite Profiles for Ethane, Ethylene, Acetylene, and Propane
at Simsbury Site for the 39-Day Period 20
4-6 Composite Profiles for Ozone, Freon-11 and Carbon-Tetrachloride
at Simsbury Site for the 39-Day Period 21
4-7 Some Pollutant and Meteorological Profiles at 20-Minute Intervals
During Evening Hours of August 11, 1975 22
4-8 Daily Maximum Ozone and Freon-11 at Simsbury Site During
July 15-20, 1975 23
4-9 Flight Pattern and Ozone Results for New York Urban Plume
Flight During the Evening Hours of August 9, 1975 23
4-10 Vertical Profiles of Ozone and Temperature at Extreme of
New York Urban Plume Flight of August 9, 1975 25
4-11 Ozone (in ppb) and Other Pollutant Results for Boston Urban
Plume Study Conducted During Evening Hours of August 18, 1975. . 25
4-12 Ozone (in ppb) and Other Pollutant Results for Afternoon
Flight Conducted on August 10, 1975 '. 26
4-13 Computer-Derived Density Plot of Cross-Sectional Patterns for Ozone
(ppb) Constructed from the Vertical and Horizontal Measurements
Made During the August 10, 1975 Flight 27
4-14 Vertical Ozone and Temperature Profiles on July 27, 1975 at
Sites Located in Central Vermont and Southwest Connecticut .... 28
5-1 Geographic Location of Rawinsonde and PIBAL Stations 32
6-1 Flight Pattern and Ozone Results (in ppb) for Afternoon Flight
of August 14, 1975 37
6-2 Flight Pattern and Ozone Results (in ppb) for Afternoon Flight
of August 27, 1975 38
6-3 Vertical Profiles of Various Pollutant and Meterological
Variables Measured by the B-26 Aircraft 38
6-4 EPA-Las Vegas Field Calibration Scheme 39
7-1 Diurnal Variation of I Paraffins, I Aromatics, and E Olefins as
Percentage of Total Nonmethane Hydrocarbons, Chickatawbut
Hill, July 18, 1975 42
7-2 Diurnal Variation of Hydrocarbon Compounds, Chickatawbut
Hill, July 18, 1975 43
7-3 Typical Chromatograms of Hydrocarbon-Free Air in Tedlon Bag
Irradiated by Simulated Sunlight for 6 Hours 44
7-4 Diurnal Hourly Concentrations of Ozone, Carbon Monoxide,
Acetylene, and Visibility, Chickatawbut Hill, July 18, 19, 1975. . . 45
7-5 Diurnal Hourly Average Concentrations of Ozone, Nitric Oxide,
Nitrogen Dioxide, and Carbon Monoxide, Chickatawbut Hill,
August 21 and 22, 1975 46
vii
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Number page
7-6 Diurnal Hourly Average Concentrations of Ozone, Nitric Oxide,
Nitrogen Dioxide, and Carbon Monoxide, Chickatawbut Hill,
July 28 and 29, 1975 46
7-7 Diurnal Hourly Average Concentrations of Ozone, Nitric Oxide,
and Nitrogen Dioxide, Chickatawbut Hill, July 23 and 24, 1975 ... 47
7-8 Comparison of JFK Building with Chickatawbut Hill,
July 31, 1975 48
7-9 Comparison of JFK Building with Chickatawbut Hill,
August 11, 1975 48
7-10 Frequency Distribution of Time Versus High Hourly Average
Ozone Concentrations 49
7-11 Frequenccy Distribution of Wind Direction at Times of High
Ozone Concentrations 50
8-1 Location of Ozone Monitoring Stations Operating in Southern
New England During 1975 Oxidant Transport Study 54
8-2a Monthly Maximum and Average Ozone Concentrations by Hour
for Bridgeport, Conn., July 1975 58
8-2b Monthly Maximum and Average Ozone Concentrations by Hour
for Eastford, Conn., August 1975 59
8~3a Monthly Maximum and Average Ozone Concentrations by Hour
for Eastford, Conn., July 1975 59
8-3b Monthly Maximum and Average Ozone Concentration by Hour
for Eastford, Conn., August 1975 59
8-4a Monthly Maximum and Average Ozone Concentrations by Hour
for Framingham, Mass., July 1975 60
8-4b Monthly Maximum and Average Ozone Concentrations by Hour
for Framingham, Mass., August 1975 60
8-5a Monthly Maximum and Average Ozone Concentrations by Hour
for Litchfield, Conn., July 1975 61
8-5b Monthly Maximum and Average Ozone Concentrations by Hour
for Litchfield, Conn., August 1975 61
8-6a Daily Maximum Ozone Concentration at Middletown, Conn.,
July 1975 62
8-6b Daily Maximum Ozone Concentration for Middletown, Conn.,
August 1975 62
8-7 Daily Maximum and Average Ozone Concentrations for Litchfield,
Conn., July 1975 63
8-8a Daily Maximum and Average Ozone Concentrations for Scituate,
R. I., July 1975 64
8-8b Daily Maximum and Average Ozone Concentrations for Scituate,
R. I., August 1975 64
8-9a Daily Maximum Ozone Concentration for Framingham, Mass.,
July 1975 65
viii
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Number Page
8-9b Daily Maximum Ozone Concentration for Framingham, Mass.,
August 1975 65
8-10a Daily Maximum Ozone Concentration for Danvers, Mass.,
July 1975 66
8-10b Daily Ozone Concentration for Danvers, Mass., August 1975 .... 66
8-11 Daily Maximum and Average Ozone Concentrations for Fairhaven,
Mass., August 1975 67
8-12 Daily Maximum Ozone Concentrations for Groton, Conn.,
August 1975 67
8-13 Hourly Ozone Concentrations at Three Connecticut Sites,
July 23-24, 1975 68
8-14 Hourly Ozone Concentration at the Two Rhode Island Sites,
July 23-24, 1975 68
8-15 Hourly Ozone Concentration at Three Massachusetts Sites,
July 23-24, 1975 69
8-16 Hourly Ozone Concentrations at Four New England Sampling Sites. . 69
9~1 Ozone Results for Southern Flight During Morning Hours of
August 10, 1975 72
9~2 Ozone Results for Southern Flight During the Afternoon Hours
of August 20 1975 73
9-3 Ozone Results for Southern Flight During the Afternoon Hours
of August 21, 1975 74
9-4 Ozone Results for Northern Flight During Morning Hours
of August 10, 1975 75
9-5 Ozone Results for Southern Flight During Afternoon Hours
of August 10, 1975 76
9-6 Ozone Results for Southern Flight During Afternoon Hours
of August 19, 1975 77
9-7 Ozone Results for Northern Flight During Afternoon Hours
of August 15, 1975 79
9-8 Ozone Results for Northern Flight During Afternoon Hours
of August 20, 1975 80
9-9 Vertical Profiles for Ozone at Several Sampling Sites at
Various Sampling Times for August 10, 19, and 20, 1975 81
9-10 Ozone Results for the Southern Flight During Morning Hours
of August 21, 1975 83
9-11 Ozone Results for Northern Flight During Morning Hours
of August 21, 1975 84
9-12 Ozone Results for Northern Flight During Afternoon Hours
of August 21, 1975 85
IX
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Number Page
10-1 Sampling Sites in the New York City Area 88
10-2 Ozone and Nitrogen Oxides Levels at New York City Site 88
10-3 Ozone and Inversion Data (Measured by Acoustic Sounder)
at World Trade Center and Roosevelt Island 89
10-4 Flight Pattern and Ozone Results (in ppb) for Morning
Flight of June 23, 1975 90
10-5 Vertical Ozone Profiles at Three Locations Measured During
Morning Flight of June 23, 1975 90
10-6 Flight Pattern and Ozone Results (in ppb) for Afternoon
Flight of June 23, 1975 90
10-7 Vertical Ozone Profiles at Two Locations Measured During
Afternoon Flight of June 23, 1975 90
10-8 Ozone Isopleths for 1100-1200 Time Period of June 23, 1975,
Constructed Using Data from a Network of 95 Ground-Based
Sampling Stations 92
10-9 Ozone Isopleths for the 1300-1400 Time Period of June 23, 1975,
Constructed Using Data from a Network of Ground-Based
Sampling Stations 92
10-10 Ozone Isopleths for the 1500-1600 Time Period of June 23, 1975,
Constructed Using Data from a Network of 95 Ground-Based
Sampling Stations 92
10-11 Ozone Isopleths for the 1700-1800 Time Period of June 23, 1975,
Constructed Using Data from a Network of 95 Ground-Based
Sampling Stations 93
10-12 Geographic Location of the 95 Ground-Based Ozone
Sampling Sites 93
10-13 Composite Calibration Chromatogram 95
10-14 Some Results of Detailed Hydrocarbon Analyses for Typical
Ambient Air Sample 95
10-15 Hydrocarbon, Nitrogen Oxides, and Ozone Observations
During Study Periods of July 7-11 and 14-18 in
New York City 96
11-1 Kl Calibration Curves for Ozone at Sample Flow Rates of
300-400 cm3/min and 800 cm /min 100
11-2 Ozone Audit Results at the Connecticut Sampling Sites 102
11-3 Ozone Audit Results for Massachusetts and Rhode Island
Sampling Sites 103
11-4 Ozone Audit Results for Special Study Participants and
for New Hampshire Sampling Sites 104
12-1 Diagram of RTI Outdoor Smog Chamber 109
12-2 Average Maxima, Minima, and A0_ Concentrations as Function
of NOX Concentrations at Sunrise on Second and Third Days
of Irradiation 113
x
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Number Page
12-3 Average Maxima, Minima, and A03 Concentrations as Function
of Nonmethane Hydrocarbon Concentrations on Second and Third
Days of Irradiation 114
12-4 Average Maxima and A 03 as Function of Nonmethane Hydrocarbon
to Oxides of Nitrogen Ratio 115
12-5 Ozone Profiles Over Second Day Irradiations for Same Initial
Conditions and Different Dilutions in Chamber 1 115
12-6 Vertical Ozone Soundings at Wilmington, Ohio, on
August 1, 1974 117
12-7 Mean Diurnal 03 Concentration at Wilmington, Wooster, and
McConnelsville, Ohio, from June 14 to August 31, 1974 118
12-8 Mean Diurnal NO£ Concentration at Wilmington, Wooster, and
McConnelsville, Ohio, from June 14 to August 31, 1974 118
12-9 First Day Chamber Concentration Profiles 119
12-10 Second Day Chamber Concentration Profiles 119
12-11 Third Day Chamber Concentration Profiles 120
12-12 Typical 3-Day Profiles for NO, NO2, and 03 121
13-1 Wind Rose (left) Showing Wind Directions of June, July, and
August 1975. Cumulative Hours of Ozone Related to Wind
Direction (right) Shows the Predominance of Ozone Transported
to Nantucket Island, MA, from the Southwest 124
13-2 Percent Leaf Injury of Bel-W3 Relates Linearly to the Daylight
Hours of Ozone 20.04 ppm 126
XI
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TABLES
Number Page
3-1 Ground Level Measurements 9
3-2 Aircraft Measurements 9
3-3 Hydrocarbon Measurements (y g/m^) at Trailer Site on
July 18, 1975 12
3-4 Aircraft Hydrocarbon Measurements (pg/m^) Near Groton
(2-4 p.m.) July 18, 1975 13
4-1 Meteorological and Pollutant Measurements 18
5-1 Meteorological Data Available for the Analysis of the
Northeast Oxidant Transport Study 30
5-2 Upper Air Winds - Northeast Oxidant Study 31
5-3 Flight Locations and Meteorology 33-34
7-1 Mobile Laboratory Instrument Array 40
7-2 Comparison of Hydrocarbon Composition at Greater Boston
Area Ground Sites to Roadway and Tunnel Samples, 1975 41
7-3 Aircraft Samples Taken August 11-28, 1975 - Boston
Oxidant Study (Range of Observations) 50
7-4 Aircraft Samples Taken August 14, 1975 - Boston
Oxidant Study 51
7-5 Correlation of Ozone Versus Acetylene for EPA-LV Aircraft
Samples - Boston Oxidant Study, 1975 52
8-1 Monitoring Sites 55
8-2 Monthly Maximum Ozone Values and Frequency of Violations,
April Through September, 1975, Connecticut 56
8-3 Monthly Maximum Ozone Values and Frequency of Violations,
April Through September 1975, Massachusetts 57
8-4 Monthly Maximum Ozone Values and Frequency of Violations,
April Through September 1975, Rhode Island 57
9-1 Observed Upwind Average and Downwind Maximum Ozone
Concentrations 78
9-2 Meteorological Conditions, 1000 and 2000 EDT, Fort Totten,
New York, August 21, 1975 84
10-1 Listing of Monitors Supplying Data Used in Making Ozone
Isopleths - by State 94
11-1 Location of Ozone Collaborator Sites 99
XII
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Number Page
11-2 Neutral Buffered Kl Calibration Data, June 20 to September 4,
1975, Sample Flow 300 to 400 cm3 min 100
11-3 Bendix Instrument Response to Two Settings of Aid
Generator During Period May 20 to June 17, 1975 100
11-4 Comparison of Kl Calibration Using Flows of 300
and 800 cm3/min 100
11-5 Summary of Audit Data by Group 105
11-6 Variable Parameters Used in the Kl Calibration Method 105
11-7 Interlaboratory Calibration, Greenwich, CN, August 14, 1975 . . . .106
11-8 Interlaboratory Calibration, National Bureau of Standards
Calibrator 108
12-1 Selected Results from the July 28-30 Three-Day Chamber
Runs Ill
12-2 Net Ozone Generated on Second and Third Days of Irradiation
as a Function of Oxides of Nitrogen and Nonmethane
Hydrocarbon/Oxides of Nitrogen Ratio 112
12-3 Dark-Phase Ozone Half-Lives in Smog Chamber Runs 116
12-4 Selected Results from the August 4-6 Three-Day Runs 122
13-1 Cumulative Hours During Which Ozone Levels Were >0.04 ppm . . .125
13-2 Cumulative Daylight Hours (6 a.m. to 9 p.m.) of Ozone
20.04 ppm, and Mean Percent Plant Injury Due to Ozone
at Each Area of the Grid 125
Xlll
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PROCEEDINGS OF SYMPOSIUM
ON
1975 NORTHEAST OXIDANT TRANSPORT STUDY
Research Triangle Park, North Carolina
January 20-21, 1976
1. INTRODUCTION
Joseph J. Bufalini and William A. Lonneman
Environmental Sciences Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC
On January 20-21, 1976, a symposium was conducted in Research Triangle Park,
NC, to present preliminary results of an oxidant transport study performed during the
summer months of July and August 1975 in the New England area. These studies were
conducted by the U.S. Environmental Protection Agency (EPA) and EPA-funded re-
search teams to investigate ozone and ozone-precursor transport in the highly popu-
lated and highly polluted source areas of the northeast.
The study was organized in response to an EPA Region I request to investigate
high nighttime ozone levels at several sampling sites throughout Region I, appar-
ently the result of transport from upwind sources located southwest of Region I.
These observations bring in question the effectiveness of a local transportation con-
trol strategy if high ozone concentrations are the result of upwind sources. Since
previous studies conducted in the midwest during the summer months of 1974 show
ozone and ozone-precursor transport as a real problem the necessity of a region-
wide or, in the case of the highly populated northeast, a multiregion control strategy
is suggested.
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The January 20-21 symposium consisted primarily of the presentation of pre-
liminary field study results by the principal investigators involved in the north. j.st
study. This includes sampling programs conducted in both EPA Regions I and II.
Also included in the symposium were presentations of results from pertinent labo-
ratory experiments funded by EPA to investigate the c/zore potential of simplified
surrogated hydrocarbon and nitrogen oxide mixtures in outdoor irradiation cham-
bers . The principal features of these studies were the investigation of long-term
irradiation effects and ozone potential of these surrogated mixtures during second
and third day irradiations .
In addition to the northeast study, results were presented from other ozone
transport studies conducted during the summer months at other areas of the United
States. These include following a high pressure system from its formation in the
northwest as it moves south and eastwardly. During these high pressure movements,
concentrations of ozone and its precursors increase due to the passage of this system
over areas of increasing population and anthropogenic activity. The results from a
second study conducted in the Houston-Gulf Coast area were also presented. The
general purpose of this study was to investigate the relationship of high and low
ozone concentrations and associated backward air mass trajectories. A summary of
this presentation will not be included in this manuscript; however, an EPA report
of the detailed result of these studies is available (EPA-450/3-76-033, The Forma-
tion and Transport of Oxidant along Gulf Coast and Northern United States) .
During the course of the meeting, a short impromtu presentation was made of an
active EPA contract by Mr. Phillip Youngblood. This contract was designed to de-
termine the relationship of oxidant levels to meteorological features. The data used
for this contract consisted of available data from previous field study activities. Mr.
Youngblood reported that the measurement of Sr90 in the atmosphere suggests that
stratospheric intrusion of ozone is minimal.
There were two aspects of this study that were not covered in the meeting of
January 20-21. These were (1) the possibility of using tracers for the 1975 study
and (2) the plant damage study done by Dr. John Spengler (Harvard University,
School of Public Health) .
During the numerous meetings held both in Research Triangle Park, NC, and Bos-
ton, MA, before the study was undertaken, we had discussed the use of tracers to bet-
ter follow air trajectories into the Region. Since SF& had been used in the past, we
thought that this compound could be considered as a possible candidate for tracer work.
However, after talking to Mr. Gil Ferber of the National Oceanographic and Atmospheric
Administration (NOAA) at Rockville, MD, we concluded that SF& would not be a suit-
able tracer. The reason for this is that Mr. Ferber conducted a study in 1971 and
found that the SF& concentration varied from 10~13 to IQ-12 (v/v) . His studies ex-
tended from New England to the Carolinas and as far west as Chicago. Many local
sources of SFfc were detected, and it was impossible to determine a single plume.
Since SF& was apparently unsatisfactory as a tracer, we then discussed the pos-
sibility of using natural emissions of nuclear reactor power plants. Xenon 133 was
considered by Mr. C. Fitzsommons (EPA-Las Vegas). Within the states of New
Jersey, New York, Connecticut, Massachusetts, and Vermont, there are five power
reactors that emit radioactive noble gas. However, according to Mr. Fitzsommons,
the samples have to be cryogenically separated and subsequently counted with a
scintillation spectrometer. The separation takes 2 to 3 hours. Because of the
extremely tight schedule for the Las Vegas B-26 aircraft, it was decided not to burden
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the personnel with the extra heavy work schedule entailed in Xenon 133 analyses.
One last attempt was made to use tracers. This was to contact Metronics Associ-
ates to investigate the possible use of fluorescent particles. The cost for the study
was much too high, and it was then decided to abandon the use of tracers for the
1975 Oxidant Study.
Ms. M. Drucker (EPA Region I) suggested early in the study that Dr. Spengler
was interested in the study and that it might be mutually beneficial if the various
groups (Washington State University, Battelle, EPA) took care of some tobacco
plants for Dr. Spengler. Plants were sent to the groups by Dr. Spengler, and the
three groups were to water and visually inspect the plants every day. Although we
neglected to invite Dr. Spengler to the Conference, Dr. Spengler graciously con-
sented to supply a manuscript of his findings.
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2. OPENING REMARKS
Joseph J. Bufalini
Environmental Sciences Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC
We first became aware of the possibility of high ozone in areas downwind from
major cities (rural areas) through our chamber studies in the middle sixties. At
that time, it was noticed that high ozone/oxidant concentrations could be ootained by
irradiating HC and NOX mixtures for a second day, i.e. , a so-called reacted hydro-
carbon-NOx mixture could be irradiated a second day (after sitting overnight) and
produce a significant quantity of ozone. Another observation that was made with
these chamber studies was that very little hydrocarbon and almost no oxides of nitro-
gen were needed to produce oxidant concentrations greater than 0.1 ppm. This was
accepted and explained by smog chamber specialists as the "dirty chamber effect."
Chamber studies also showed that the so-called least reactive hydrocarbons also pro-
duced high concentrations of ozone when high hydrocarbon/NOx ratios were employed.
This observation is especially relevant to ozone and ozone-precursor transport since
this is the condition that would be expected in rural areas. The reactive hydrocar-
bons , i.e., the olefins, are expected to have reacted almost completely. The aromatics
should for the most part also be gone. The only remaining hydrocarbons are the par-
affins. Since most of the NOX has also reacted, the conditions are appropriate for hav-
ing the paraffins under conditions of maximum reactivity for ozone production. Also
relevant here are the findings of the old CAPI-6 group. This group consisted of smog
chamber specialists that used their chambers to check out the reactivity of certain hy-
drocarbons. The stability of ozone in the chambers was also tested. The results
showed that ozone could have a rather long half-life even when the lights are turned on.
What does all this have to do with ozone transport? Well, all of the information
was here in the smog chamber data. The smog chambers showed (1) very little HC
is needed for 03 production with almost no NOX, (2) the so-called unreactive hydro-
carbons could produce ozone at a high HC/NOX ratio, and (3) ozone, once produced,
would be quite stable and would stay around a long time. All that was needed was an
experiment to test the hypothesis that high 63 could be expected downwind from ma-
jor cities. However, since our interests at that time (middle to late sixties) were con-
centrated on the measurement of the air quality in various cities (mostly Los Angeles
and New York), no such experiments were performed.
At that time, the only evidence that ozone and ozone precursors could travel at
least a moderate distance was the data from Riverside, CA. In Riverside, two ozone
maximums are observed: one between 11 a.m. and 1 p.m. and the other later in the
afternoon (4 to 6 p.m.) . Those of you that have heard Dr. Jim Pitts speak on this
subject well remember his slides. The slides show the smog as it travels from Los
Angeles to Riverside. In the last few years, there have been reports of high ozone in
Palm Springs and also Indio. These cities are approximately 110 and 130 miles away
from downtown Los Angeles.
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Most people have accepted the fact that the Los Angeles Basin is unique. Pollu-
tants really cannot go anywhere, and that is the reason for the smog. However, in
the late sixties and early seventies, the Mt. Storm, WV, Christmas tree incident
arose. This area in West Virginia is approximately 80 miles away from a large city,
(Pittsburgh, PA) . A thorough study by the Research Triangle Institute, with En-
vironmental Protection Agency funding, indicates that the Christmas tree damage
arose from high levels of ozone. The high ozone levels in this area are attributed
to ozone and ozone-precursor transport from upwind sources.
Since the Mt. Storm incident, a number of reports have appeared that indicate
ozone and ozone precursors can travel great distances. I have reference here to the
work of Stasiuk and Coffey in New York State and that done by EPA Region IV in
Florida.
In 1973, EPA awarded a contract to Washington State University (Westburg and
Reamussen) to look at the oxidant transport problem. Our thoughts were to have sev-
eral different cities studied. This was to be done by ground level stations and by air-
craft. Two cities that were investigated in 1973 were Phoenix, AR, and Houston, TX.
In the Phoenix study, the ozone levels found by the aircraft at 1000 feet above
ground level were ^ 50 to 60 ppb upwind of the city. Downwind (6 to 10 miles), the
ozone levels would increase to 100 to 140 ppb. After 30 to 40 miles downwind, the
ozone would again decrease to 60 to 70 ppb. In Houston, some unusual observations
were made. The ozone levels were found to be 110 to 130 ppb at 30 to 40 miles upwind
of the center of the city. At 10 miles downwind, 330 ppb was observed, and some 40
miles downwind, the 63 levels decreased to 120 to 180 ppb. What was apparently hap-
pening in Houston was that the ozone levels were high even before pollutants were
picked up from the city. The city did have a significant effect on the 03 levels, but
this was for only short distances (30 to 40 miles) .
In 1974, EPA took part in a study in which the entire midwestern area of the
United States was covered with three aircraft situated in the Ohio cities of Wilming-
ton, Canton, and Dayton. The findings of the 1974 study were: (1) the oxidant
standard is exceeded in rural areas more than in urban areas, (2) area pollution ex-
tends beyond a radius of 150 miles, (3) a major urban area has an observable influ-
ence on the order of 30 to 50 miles downwind, and (4) when a region is under the
influence of a synoptic high pressure system, i.e., a region characterized by clear
skies and a weak disorganized flow, high ozone levels can be expected.
The results of last year's research program imply that control of hydrocarbons
from any individual city will reduce but not necessarily prevent high concentrations
of ozone. The data suggest that controls must be considered on a regional level.
Controls must also be considered for oxides of nitrogen.
This past summer (1975) we undertook an oxidant transport study in New England.
This study was undertaken at the request of EPA Region I. The Region had complained
that they could not implement control plans since the high ozone levels that were ob-
served suggested nonlocal sources. A study of their data did indeed suggest this,
since high levels of ozone were observed in the late evening or early morning hours.
With two contractors (Battelle and Washington State University) along with the EPA
Las Vegas aircraft, we covered most of the Northeast. Later in the study (from Au-
gust 10 to August 21) the Interstate Sanitation Commission, with EPA funding, also
participated in the study and performed aircraft sampling measurements of O^ over
Pennsylvania, New York, and New Jersey.
-------
3. OZONE AND OTHER POLLUTANTS MEASURED
BY WASHINGTON STATE UNIVERSITY
DURING THE 1975 NORTHEAST OXIDANT TRANSPORT STUDY
H. Westberg
Washington State University
Pullman, WA
This presentation, which concerns Washington State University's part in the 1975
New England oxidant study, can be divided roughly into three parts: (1) a review of
program objectives, including some of the specific goals; (2) a brief description of
how our phase of the program was designed to accomplish these goals; and (3) a
look at data relevant to various aspects of oxidant production and transport in south-
ern New England.
The primary objectives of the program were:
1. Monitor ozone and ozone precursors over the entire southern New England
region.
2. Provide an in-depth analysis of ozone transport into and within the New
England region.
The first objective has been completed; interpretation of the data collected is just
beginning.
The following list indicates specific areas of interest; it is not complete, but
shows those areas most important to our part of the study.
1. Oxidant formation and transport within urban plumes.
2 . Oxidant behavior during stagnation periods.
3. Coastal Seabreeze effect on oxidant levels.
4. Relationships between oxidant levels and inversion layers .
5. Weekend ozone behavior.
6. Ozone transport in the Connecticut River Valley.
Oxidant formation and transport in the plumes emanating from New York City and
Boston were of prime interest. Later in this presentation, data will be shown con-
cerning this aspect of the program. I will also be describing oxidant behavior in re-
lation to passage of high pressure systems through the region (stagnation periods) .
In addition, data relevant to specific interests 3 and 4 will be mentioned.
In order to satisfy the sampling objectives of the program, a triangular network
of monitoring base stations was set up in southern New England. This is shown on
the map in Figure 3-1.
-------
ATLANTIC OCEAN (N
Seotoi I = 38ml
We were located on the southern
•Connecticut coast south of Groton .
Battelle's base of operations was near
Simsbury, CN, and the two EPA groups
were in the Boston vicinity. It was
felt a triangular design such as this
provided optimum coverage of the
study area. Washington State Univer-
sity had access to air masses that
originated in the New York City area
and moved out over the Atlantic Ocean
and Long Island Sound. Battelle could
monitor air parcels coming into the
region from the northwest, while the
EPA groups were positioned to pro-
vide upwind and downwind coverage
of the Boston metropolitan area.
Figure 3-1. Geographic location of special
study groups for I975 Northeast Oxidant
Transport Study.
Our main sampling trailer was
located near the tip of Avery Point
south of Groton (see Figure 3-2) .
The close proximity of the trailer
and airport made it possible to fly
low passes for cross-checking the airborne and ground ozone instruments. We also
collected bag samples for hydrocarbon analysis at a rural inland site northwest of
Groton. This was near the Devil's Hopyard State Park about halfway between Gro-
ton and Hartford.
Aircraft flight paths were designed to provide maximum coverage of the south-
ern New England region. During the first half of the study period when two air-
planes were operating, we concentrated on the eastern portion of the region. We
flew north from Groton to the proximity of the Massachusetts border and then head-
ed east toward Boston (see Figure
3-3) . The section of this first leg
from Putnam to the turn point over-
lapped with Battelle's flight path and
thus allowed cross-checking of in-
struments in the two aircraft. The
remainder of our route consisted of a
counterclockwise arc of 18 miles ra-
dius around Boston followed by re-
turn to Groton via Providence, RI.
Vertical profiles were flown at two
points along the flight path. The lo-
cation of these soundings was gen-
erally in an area upwind and down-
wind of Boston.
When not flying the Boston loop,
we generally covered an area south
of Groton as shown in Figure 3-4.
The objective here was to monitor pol-
lutant behavior over water.
+ INLAND SITE
*
DfVW.'l HOfMMW
Figure 3-2. Location of Groton study site.
-------
Uv£tf HAMPSHIRE '
y6
Figure 3-3. Aircraft flight pattern for Boston
Loop.
Figure 3-4. Aircraft flight pattern for
South Boston flights.
In early August when the EPA-Las Vegas plane arrived, our primary routes
covered the southwestern portion of the region during morning hours and the south-
eastern area during afternoons. These flight patterns are shown in Figures 3-5
and 3-6.
In concluding this discussion of program design, the Tables 3-1 and 3-2 list the
measurements we made. All parameters shown in Table 3-1 were monitored contin-
uously, with the exception of individual light hydrocarbons. These were generally
collected over 2-hour periods during morning, afternoon, and evening hours. Not
MASSACHUSETTS
;r
NEW
YORK
Scol* 1 • 21 n»
Figure 3-5. Typical southwestern flight
pattern from Groton.
o
MASSACHUSETTS
PUTNUU O
CONNECTICUT
ATLANTIC OCEAN
Figure 3-6. Typical southeastern flight pattern
from Groton.
-------
listed in this table is the measurement of upper level winds. This information was
obtained from pibal observations each morning and afternoon. Data from aircraft
instrumentation (Table 3-2) were continuously recorded on magnetic tape. Bag
samples for hydrocarbon analysis were collected at various points along the flight
path.
Table 3-1.
GROUND LEVEL MEASUREMENTS
Ozone
Oxides of nitrogen
Total hydrocarbon
Methane
Carbon monoxide
Individual C2-Ce HC
Halocarbons
Wind speed
Wind direction
Turbulence
Dew point
Solar radiation
Temperature
Vertical temp.
discontinuity
(acoustic radar)
Oxidant behavior in the plumes downwind
of Boston and New York City was of special
interest in this study. The following figures
will provide examples of the type of informa-
tion we collected concerning urban plumes.
On July 22, afternoon winds along the
Connecticut coast were from the southwest
quadrant. The flight path shown in Figure
3-7 is typical of those used to monitor the area
downwind of the New York-New Jersey region
under these wind conditions. The numbers
shown are ozone levels at specific points along
the route. Unless otherwise specified, the
flight altitude was near 1000 feet above mean
sea level. The aircraft departed Groton about
1: 15 and, heading west, climbed to 7000 feet
over New Haven. After spiraling down to 1000 feet, it headed south across Long Is-
land Sound and then southeasterly to a point about 30 miles south of Long Island. As
can be seen, ozone levels were generally in the 90- to 100-ppb region up to the south-
ern coast of Long Island, at which point they increase to greater than 140 ppb over the
ocean. On the final leg into Groton, this area of elevated ozone was examined more
closely by flying a series of vertical profiles across the high ozone region.
The northernmost profile (point g in Figure 3-7) is shown in Figure 3-8. Two
temperature inversions are obvious. Note the close correspondence between these
temperature discontinuities and the vertical ozone profile. The high ozone concen-
trations near the surface fall off quite rapidly up to the base of the surface inversion,
indicating poor mixing in this region. Between the two temperature breaks, the de-
crease with altitude is much less. However, the rapid decrease in ozone concentra-
tion with altitude is once again apparent above the 3500-foot level.
Figure 3-9 shows the lower portion of the southermost profile in this series (point
d in Figure 3-7) . The ozone and temperature profiles are similar to that shown in
the previous figure, with highest oxi-
Table3-2. AIRCRAFT MEASUREMENTS dant levels recorded below 1000 feet.
Ozone
Condensation nuclei
Visual range (nephelometer)
Temperature
Relative humidity
Navigational parameters
Bag/can samples (hydrocarbons, halocarbons, NOX, etc.)
Shown in Figure 3-10 is a vertical
profile in the region between the two
shown previously. Ozone levels near
the surface are approaching 200 ppb.
To summarize, on this day the re-
gion of highest oxidant stretched for ap-
proximately 25 miles in the north-south
direction and extended from the surface
to about 1000 feet. This type of ozone
distribution was commonly observed
-------
06
ATLANTIC
Figure 3-7. Ozone results (in ppb) for air-
flight downwind of New York - New Jersey
area during afternoon hours of July 22,1975.
over the water when winds were
from the west.
The following figures wiii
show additional features of this
oxidant plume. On several occa-
sions, the position of the plume
was shifted to the north, encom-
passing the Groton area. July 18
is a good example. Winds on this
day were from the southwest.
Figure 3-11 shows oxidant
levels for the 4-day period, July
17-20, recorded at our ground
trailer site south of Groton. Ozone
levels were very low on the 17th,
up to about 160 ppb on the 18th,
and then back down below 60 ppb
on the 19th and 20th. On all four
of these days, solar intensity was
high.
In Figure 3-12, it can be ob-
served that the burst of ozone on July 18 was accompanied by a simultaneous jump in
Freon-11 levels. Other anthropogenic source indicators such as carbon monoxide and
acetylene also exhibited coincident concentration increases.
Table 3-3 shows individual light hydrocarbons collected on July 18 at the trailer
site. Data are included for the morning and evening hours. Note that hydrocarbon
behavior is opposite that normal-
———- ly associated with localized photo-
chemical processes. The substan-
tial increase in hydrocarbon levels
from morning to afternoon is indi-
cative of a transport process.
ALTITUDE
(«K>3 ftMSU 5
JULY 22
(•v 3:00 PM)
eo ee TO TO BO _
TEMP (°F1
\
\
PI*
Figure 3-8. Vertical profiles of ozone and
temperature over point g (Figure 3-7).
Aircraft flights on July 18
showed once again that the high-
est ozone levels existed near the
surface. This is shown in Figure
3-13. Hydrocarbon concentrations
were also highest at lower eleva-
tions as shown in Table 3-4. The
500-foot sample was fairly compar-
able with samples collected on the
ground during afternoon hours.
Both the ozone and hydrocarbon
levels were low at 7000 feet.
On several occasion?;, our
flights around Boston fchow<;'.i r,l»:
vated ozone levels in the downwind
area. An example is the morning
10
-------
ALTITUDE
dKD3 ftMSL)
LS
TO 80 80 100 110 EO
ppb 03
Figure 3-9. Vertical profiles of ozone and
temperature over point d (Figure 3-7).
ALTITUDE
(,»S «MSL) 4
3
2
I
0
JULY 22
3:30 Ptt)
70 72 74 78 78 80
TEMP (»F)
100
MO
03
WO
Figure 3-10. Vertical profiles of ozone and
temperature between points d and g
(Figure3-7).
flight of August 3, shown in Fig-
ure 3-14. Winds were from the
northeast. Ozone levels along
the upwind section of the arc are
in the 35-ppb range, while those
in the southwest quadrant (down-
wind) are up in the 120's. In
addition, there was a significant
increase in the downwind ozone
concentration from 11: 00 to 12: 30
p.m.
Figure 3-15 shows an ex-
panded view of the southwest
portion of the arc. We entered
the arc from the northern leg
at about 11: 00 a.m. As the
plane started its counterclock-
wise circle, ozone concentra-
tions in the 60- to 80-ppb range
were recorded. By the time the
plane had completed the circle
of Boston (approximately 12: 30
p.m.), ozone levels in the south-
west quadrant had increased by
30 to 40 ppb.
As indicated earlier, oxi-
dant behavior during high pres-
sure periods was an area of
specific interest. A high pres-
sure system from the west en-
tered southern New England
during the early morning hours
of August 9. This system con-
tinued to influence the region
for 6 days. As can be seen in
Figure 3-16, ozone levels at our
trailer site in Groton exceeded
100 ppb on each of these days.
Wind flow at the 850-mb level
was from the northwest through-
out most of this period.
The days of August 10 and 13 are interesting in that the normal diurnal ozone
patterns are distorted by late evening peaks. Figure 3-17 shows expanded views of
ozone curves for the 10th and 13th. These nighttime ozone peaks must result from
transport into the Groton area. Aircraft data show that the transport process differed
somewhat on these two days. On August 10, we flew a cross-sectional pattern per-
pendicular to the general wind flow. Highest ozone levels were recorded to the south
over water (see Figure 3-18) . The vertical ozone profile on this afternoon showed
the highest levels to be quite close to the surface (see Figure 3-19) .
a
-------
MO
140
KX>
IU AA
z 80
o
8 «
40
20
TIME / DATE
TIME / DATE
Figure 3-11. Diurnal ozone patterns at
Groton ground site during July 17-20,
1975.
Figure 3-12. Diurnal profiles for ozone and
Freon-11 at Groton ground site during July
17-20, 1975.
V
Table 3-3. HYDROCARBON MEASUREMENTS
-------
ALTITUDE
(,I03 ftMSU *
4
3
2
I
0
JULY 18
(•v 2:00 PM)
5S«O657D7SaOW.
TEMP CF)
\
\
\
\
\
\
BO 70
90
ppb 03
no
130
Figure 3-13. Vertical profiles for ozone and
temperature over Groton during afternoon
of July 17-20, 1975
Table 3-4. AIRCRAFT HYDROCARBON
MEASUREMENTS (/ug/m?) NEAR GROTON
(2-4 p.m.) July 18,1975
Ethane
Ethylene
Acetylene
Propane
Propene
i-Butane
n-Butane
i-Pentane
n-Pentane
Total
500 feet
7.0
5.0
7.0
7.5
2.0
5.5
11.5
9.5
5.0
60
2500 feet
5.5
5.5
3.5
5.0
< 0.5
5.0
11.0
8.0
4.0
48
7000 feet
4.0
2.0
< 0.5
2.0
< 0.5
1.0
1.5
1.5
1.0
13
13
-------
ITCT
AUGUST 3, 1975
(10:00 AN to 1:20 PM)
WORCHESTER O
Figure 3-14. Ozone results (in ppb) for
morning flight of August 3, 1975.
WIND
BOSTON 080/10
HANSCOM 050/5
I2-.4O pm
I20
Figure 3-15. Expanded view of southwest
portion of arc for August 3, 1975 flight
(Figure 3-14).
14
-------
wo
MO
120
no
80
60
40
20
TIME / DATE
Figure 3-16. Diurnal patterns of ozone (in
ppb) at Groton ground site during August
9-14, 1975.
160
MO
00
KX)
80
-
40
ao
o
12 W
-8/10
24 24
-
12
-8/13-
24
-J
Figure 3-17. Expanded views of diurnal
ozone patterns at Groton ground site for
August 10 and 13, 1975.
15
-------
CONNECTICUT- I
AUGUST 10. 1975 rt HMTFORO
(4:00 to 7:00 PH)
Figure 3-18. Ozone results (in ppb) for
aircraft flight during late afternoon hours
of August 10, 1975.
ALTITUDE
UW3 ftMSL) 5
4
3
2
I
0
AUGUST 10
(A. 5iOO PM)
90
66 70 74 78 82 8«
TEMP (°F)
\
\
\
\
\
110
ppb 03
130 ISO
Figure 3-19. Vertical profiles for ozone
and temperature near Groton during
afternoon hours of August 10, 1975.
16
-------
4. OZONE AND OTHER POLLUTANTS MEASURED BY BATTELLE
DURING THE 1975 NORTHEAST OXIDANT TRANSPORT STUDY
Chester W. Spicer
Battelle Memorial Institute
Columbus, OH
The purpose of the study was, in general, the investigation of the transport of
oxidant and its precursors beyond urban areas. In particular, the study was de-
signed to investigate the formation and movement of ozone in the lower atmosphere in
and around the New England area. This study was funded entirely by the U.S. En-
vironmental Protection Agency.
Figure 4-1 shows
the 1975 Oxidant Trans-
port Study area. The
Battelle-Columbus mo-
bile laboratory and air-
craft were located at an
airport in Simsbury, CN,
approximately 15 miles
northwest of Hartford.
Table 4-1 shows the
meteorological and
chemical monitoring tech-
niques used in the Bat-
telle mobile laboratory.
The aircraft monitored
temperature and ozone
(and NOX on selected
flights) continuously. The
remaining chemical spe-
cies were collected in Ted-
lar bags for subsequent
analysis.
Figure 4-1. Topographic map of 1975 Oxidant Transport Study area.
\ We are now just get-
"\ ting the results of our
field study data from the
computer. These data in-
clude 39 days of ground
level data from Simsbury
and the results from 44
aircraft flights. Figure
4-2 contains the results
of the 39-day composite
profiles for the meteor-
ological measurements
17
-------
Table 4-1.
METEOROLOGICAL AND POLLUTANT MEASUREMENTS
Analysis
Instrument
Wind speed and direction
Temperature
Relative humidity
Global radiation intensity
03
NO
NOX
N02 (by difference)
CH4
NMHC
CO
C2H2
C2H4
C2H6
(Freon-11)
CCI4
MRI, Model 1074-2 sensor
MR I, Model 802 sensor
MR I, Model 907 sensor
Eppley Lab, 180°
pyrheliometer
REM, Model 612 chemilum-
inescence monitor
Bendix, Model 8101-B
chemiluminescence
monitor
Union Carbide, Model 3020
automated FID gas
chromatograph
Varian Series 1200 gas
chromatograph with FID
Varian Series 1200 gas
chromatograph with electron
capture detection
made at the Simsbury site. Figure 4-3 contains the 39-day composite profiles for the
ozone and nitrogen oxides. Figure 4-4 represent the composite profiles for methane,
total nonmethane hydrocarbon, and carbon monoxide. Figure 4-5 illustrates the 39-
day composite profiles for ethane, ethylene, acetylene, and propane. It appears that
the acetylene and ethylene profiles follow similar patterns, as expected since they
have a common source, namely, auto exhaust emissions. Ethane and propane follow
different diurnal patterns independent of automotive sources and apparently indepen-
dent of a common natural gas sources. This is evident during the morning and late
evening hours when other sources of propane were observed. Figure 4-6 contains
the 39-day composite profiles of ozone, Freon-11, and carbon tetrachloride.
The 39-day composite profiles in Figures 4-2 through 4-6 represent average
values observed at the Simsbury site throughout the entire study period. These av-
erages tend to smooth out the day-to-day indications of ozone and other pollutant
transport into the Simsbury area; however, they do illustrate the average pollutant
profile as well as the general data format of our final report.
Figure 4-7 shows data collected at the Simsbury site during the evening hours
of August 11, 1975. The pollutant profiles are plotted over a relatively short time
interval to demonstrate the transport of a new air mass into the area. This influx was
observed by the sudden changes in the various parameters at 2110. From the figure,
it is obvious that high ozone concentrations were observed in this new air mass.
Plots of daily maximum ozone and Freon-11 for the entire study period of July
15 through August 20, 1975, at the Simsbury site are given in Figure 4-8. The close
18
-------
=>
u.
a
o
cc
O GLOBAL IRRADIANCE: 6.000 cal/crn* - mm
a WIND SPEED: 20.0 mi/hr
WIND DIRECTION: 360 degrees
• TEMPERATURE. 30°C
• RELATIVE HUMIDITY: 100 percent
1 1 i 1
12
HOUR OF DAY
16
20
Figure 4-2. Composite profiles for meteorological measurements made at the Simsbury
site during the 39-day study period.
60
o 30
20
10
O OZONE: O.ISOppm
O NITRIC OXIDE: 0.100 ppm
A NITROGEN DIOXIDE: 0.100 ppm
• NITROGEN OXIDES: 0.100 ppm
12
HOUR OF DAY
Figure 4-3. Composite profiles for the ozone and nitrogen oxides at the Simsbury site for the
39-day study period.
19
-------
100
90
O METHANE 3t>fmC
0 NONMETHANE HYDROCARIONS. O.MffffiC
4 CARION MONOXIDE. I.Oppn
Figure 4-4. Composite profiles for methane, total methane hydrocarbon, and carbon
monoxide at Simsbury site for the 39-day study period.
O ETHANE : OJIOppmC
OETHVLENE . OJMO ppmC
i PROPANE . OMIppmC
• ACETYLENE 0.010 ppmC
HOUR OF DAY
Figure 4-5. Composite profiles for ethane, ethylene, acetylene, and propane at Simsbury site
for the 39-day "study period.
20
-------
=>
u.
o
100
90
80
70
60
o
£ 40
Q.
30
20
10
O OZONE: 0.150ppm
D FLUOROCARBON-II: 200.0 ppt
A CARBON TETRACHLORIDE: 200.0 ppt
12
HOUR OF DAY
16
20
Figure 4-6. Composite profiles for ozone, Freon-11 and carbon-tetrachloride at Simsbury site for
the 39-day study.period.
correlation between these compounds indicates that much of rural Simsbury's elevat-
ed ozone results from the-transport of urban air and is, therefore, of anthropogenic
origin.
The next group of figures include some of the results obtained from aircraft
flights. The flight patterns used during the study were designed to give extended,
simultaneous coverage of the entire New England area by two and three aircraft. The
flights were also designed to fly special missions which included:
1. Power plume studies.
2. Urban plume transport over ocean bodies.
3. Ozone transport up the Connecticut River Valley.
Figure 4-9 shows the results of a New York urban plume flight for the evening
hours of August 9, 1975. Ozone concentrations are plotted versus distance for each
sector of the somewhat triangular flight pattern. The number above the plot shows
the aircraft altitude for each sector of the flight. The resultant meteorological wind
direction is given by the arrow. As can be seen from these plots, elevated levels of
ozone were observed 150 miles downwind of the urban area.
21
-------
100
50
o
cc
. TEMPERATURE: 90°F
. OZONE: 0.2 ppm
• RELATIVE HUMIDITY: 100 percent
.TOTAL HYDROCARBON: 10ppm
NITROGEN OXIDES: 0.5 ppm
./*"*• :
"V \ /
I. V
/ s
22:40 22:20 22:00 21:40 21:20 21:00 20:40 20:20 20:00
HOUR OF DAY
Figure 4-7. Some pollutant and meteorological profiles at 20-minute intervals during evening
hours of August 11, 1975.
22
-------
7/H
1/11
I/It
t/za
Figure 4-8. Daily maximum ozone and Freon-11 at Simsbury site during July 15-20,
1975.
IATURDAY EVENING M-75 6:03-1:02
0 21 H 75
il lir
ICAIE. m»*
M 75 180 1H
DISTANCE, milti
Figure 4-9. Flight pattern and ozone results for New York urban plume flight during the
evening hours of August 9, 1975.
23
-------
Vertical profiles of ozone and temperature at the extreme of the New York urban
plume flight of August 9 (150 miles downwind of the city) are shown in Figure -. 10.
It appears that the ozone and haze both maximize at the base of the inversion. Trie
haze layer determination was a visual observation.
Figure 4-11 represents a Boston urban plume study conducted during the even-
ing hours of August 18, 1975. Concentration results of several pollutants for bag
samples collected during the flight are listed in the lower right hand corner. Bag 1
represents the first sample collected; Bag 3, the last sample. From the figure, it is
obvious that elevated ozone concentrations exceeding 0.08 ppm were observed as far
as 250 miles out over the ocean. As in the New York plume study (Figure 4-9), the
aircraft was flown in the same general direction as the meteorological wind direction;
therefore, the ozone results depict the effects of downwind urban transport.
The results of a cross-sectional flight pattern flown during the early afternoon
hours of August 10, 1975, are reported in Figure 4-12. The winds were continuous-
ly from the west during this flight. Again, pollutant results for bag samples collect-
ed during the flight are given in the lower right-hand corner. (Bag 1 is the first bag
sample along the flight path, Bag 2 is the second, and so on.) Four spirals from the
south shore of Long Island to the Massachusetts-Connecticut border were used to de-
termine vertical and horizontal distributional patterns of ozone.
The results from the vertical and horizontal measurements in Figure 4-12 were
used to construct a computer-derived density plot of the cross-sectional patterns for
ozone as shown in Figure 4-13. The abscissa and right-hand ordinate show horizon-
tal and vertical distances respectively. Ozone concentration is shown by density
shading. The number associated with each shading area represents the lowest con-
centration of ozone. The range of concentration represented by the shaded area is
that number up to that concentration associated with the next shaded area. Note that
the ozone concentration over the entire horizontal area at approximately 2700 feet is
at least 160 ppb, and is in most cases higher than the ground level measurements.
Also, the effect of the high ozone precursor sources, the New York City area, is
readily evident. In the lower right-hand column, the New York City plume exceeds
200 ppb ozone.
This plot represents the use of horizontal and vertical measurements for only four
points at different time intervals. If more simultaneous vertical measurements were
made a more precise and detailed picture would be possible.
Figure 4-14 shows vertical 03 and temperature profiles at two locations on July
27, 1975. The upper profiles were made over central Vermont (rural) and the lower
profiles over southwest Connecticut (urban) . Note the major differences in the shapes
of the ozone profiles. High levels of ozone above 8000 feet over Vermont could be due
to stratospheric transport or long distance transport of ozone precursors with upward
movement of the air mass. The lower profile shows strong influence of anthropogenic
sources below the inversion. A possible regional "background" ozone of 70 ppb asso-
ciated with a high pressure system over New England is indicated by values above the
inversion over Connecticut and values below 8000 feet over Vermont.
24
-------
X
I
uf
o
TOP OF VISIBLE
HAZE LAYER
TOP OF VISIBLE
HAZE LAYER
60 70 80
TEMPERATURE, °F
Figure 4-10. Vertical profiles of ozone and temperature at extreme of New York urban plume
flight of August 9, 1975.
175
BAG SAMPLES
o -a
i-DIRECTION OF FLIGHT
10 0 10 30 50 70
.t.HUcl -JgLJgL-jM
SCALE OF MILES
CCl3F,ppt
THC, ppmC
CH4, ppm
CO, ppm
C2H/}, ppmC
C2H2r PPmC
C2He, ppmC
CC14, ppt
1
98
1.80
1.50
0.30
0.005
0.006
0.003
--
2
120
1.94
1.50
0.50
0.010
0.007
0.004
-•
3
135
2.20
1.50
1.10
0.01 9 1
0.011
0.003
150
Figure 4-11. Ozone (in ppb) and other pollutant results for Boston urban plume study con-
ducted during evening hours of August 18, 1975.
25
-------
ATTELL__ .
HARTFORD
yCTICUT
105
V W.S.U.
EW HAVEN
»AG 2
104
101
'"POWER
-'PLANT
BAG SAMPLES
CC13F. ppt
THC, ppmC
CH4, ppm
C0,ppm
C2H4. ppmC
C2H2. ppmC
C2H6. ppmC
1
169
2.22
200
064
0008
0.007
0.007
I 2
116
193
1 72
<0.20
0.005
0003
0003
3
109
1.90
1.76
020
0.003
0.004
0.004
DIRECTION OF FLIGHT -
Figure 4-12. Ozone (in ppb) and other pollutant results for afternoon flight conducted on
August 10, 1975.
26
-------
6000-
CO
i
5000-
4000-
3000-
2000-
1000-
MASS.-CONN.
BORDER
SHORELINE
DISTANCE, miles
1
75
NO. LONG
ISLAND
i
100
SO. LONG
ISLAND
Figure 4-13. Computer-derived density plot of cross-sectional patterns for ozone (ppb)
constructed from the vertical and horizontal measurements made during the August 10,
1975 flight (Figure 4-12).
27
-------
i
X
12-
10
8
6
2
10
8
6
5:38 pm
I I I I I
4:10 pm ,
i I r
5:38pm , .
40 60
80 100 120
OZONE, ppb
140
50 60 70 80
TEMPERATURE, °F
I I I I i
90 100
Figure 4-14. Vertical ozone and temperature profiles on July 27, 1975 at sites located in
central Vermont and southwest Connecticut.
28
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5. METEOROLOGICAL DATA FOR THE 1975 NORTHEAST
OXIDANT TRANSPORT STUDY
Karl F. Zeller
Environmental Monitoring and Support Laboratory
U.S. Environmental Protection Agency
Las Vegas, NV
Any investigation of oxidant transport requires a simultaneous analysis of the
meteorological situation at the time and place of the oxidant observation. Particular-
ly, wind direction will have an effect on the location of high oxidant values, and in-
solation as well as wind dilution will have an effect on the concentration of the oxi-
dant measured. It is the purpose of this report to provide a reference to the meteoro-
logical situation day by day from July 14 through August 29, 1975, as a companion to
the oxidant data collected by aircraft monitoring platforms as well as fixed ground
monitoring stations in the New England area during the same time period.
A total list of the types and formats of the meteorological data available is given in
Table 5-1. Because the total meteorological package would be too voluminous to re-
produce, only some basic meteorological information considered sufficient for the
analysis of oxidant transport is contained within this report. Examples of this infor-
mation are listed in Table 5-2 for several sites on July 28, 1975. The data within in-
clude the following information:
1. The 1500 GMT (1100 EOT) surface weather chart.
2. The 1600 GMT (1200 EDT) weather depiction chart (nephanalysis) .
3. The 1200 GMT (0800 EDT) 850-millibar height analysis.
4. The upper air winds in 1000-foot increments .
In Table 5-2 five numbers per level at each site are given. The first three num-
bers are the wind direction and the last two are the wind speed in knots. Therefore,
the number 25013 means the wind direction is from 250 degrees on a 360 degree circle
(north equals 0 and 360) and the wind speed is 13 knots.
If more detailed meteorological data are needed, copies for specific times can be
obtained at cost on a limited basis from:
Valentine J. Descamps
Region I Meteorologist
EPA JFK Federal Building
Boston, MA 02203
Telephone number 617-223-5630 (FTS 223-5630)
or
29
-------
Karl F. Zeller
Staff Meteorologist
EPA, EMSL-LV
Air Quality Branch
P.O. Box 15027
Las Vegas, NV 89114
Telephone number 702-736-2969, x333 (FTS 595-2969, x333)
Table 5-1. METEOROLOGICAL DATA AVAILABLE FOR THE ANALYSIS
OF THE NORTHEAST OXIDANT TRANSPORT STUDY
Product
Time measurement
Format
1. Service A surface weather observations (in-
cludes: sky conditions, visibility, pressure, tem-
perature, dewpoint, wind direction and speed, al-
timeter, and comments)
2. Synoptic facsimile maps (weather charts)
a. Surface weather chart
b. Weather depiction chart
c. 850-millibar chart (5000 ft MSL)
d. 700-millibar chart (10,000 ft MSL)
e. 500-millibar chart (18,000 ft MSL)
f. Composite radar chart
3. Service C rawinsonde upper air observa-
tions for:
a. Portland, ME (72606)
b. Chatham, MA (74494)
c. Albany, NY (72518)
d. Fort Totten, NY (74486)
Hourly
3 hour
3 hour
12 hour
12 hour
12 hour
3 hour
12 hour
00-12GMT3
Teletype printout
(code)
Facsimile maps
Teletype printout
(code)
aLimited additional low altitude soundings were taken at 1800 GMT (1400 EOT) at the four
rawinsonde stations listed in item 3. The wind direction and speed data are listed in this
report. The pressure, temperature and dewpoint data can be obtained from Mr. Karl Zeller.
A separate report on PIBAL observation (upper air winds) collected at Avery
Point, Putnam, and West Springfield and low altitude radiosonde observations (tem-
perature and dewpoint lapse rates and upper air winds) collected at the Massachu-
setts Institute of Technology in Boston (Figure 5-1) was prepared by The Research
Corporation (TRC) of New England and is available through the Region I meteorologist.
In addition to the meteorological data, Table 5-3 is included to provide a quick
reference to the weather as well as the general location of sampling flights for each
of the three participating aircraft per day.
30
-------
Table 5-2. UPPER AIR WINDS - NORTHEAST OXIDANT STUDY3
(Heights in 1000-foot increments)
Date: July 28, 1975
Height
Time
Sfc.
1
2
3
4
5
6
7
8
9
10
12
Time
Sfc.
1
2
3
4
5
6
7
8
9
10
12
Time
Sfc.
1
2
3
4
5
6
7
8
9
10
12
Portland
ME
0800 EOT
13003
27522
27023
27025
26524
25026
1400 EOT
2000 EOT
19008
23524
24025
24524
24523
24023
24022
24021
25520
25520
25521
25014
Fort
Totten
NY
0800 EOT
24012
25525
28024
25019
26518
26518
26521
26026
26031
26039
1400 EOT
28004
28507
29508
28509
28510
28510
26512
25517
25520
26023
26525
26531
2000 EOT
18007
34004
35011
28513
28511
28012
27014
25019
25521
25022
26027
26529
Albany
NY
0800 EOT
18007
25511
28019
29020
29522
28022
27521
28022
27524
25530
1400 EOT
2000 EOT
25017
26524
Chatham
MA
0800 EOT
26005
26518
27518
28521
29023
26522
26521
27020
27021
27021
27027
1400 EOT
20022
22032
23035
23534
24033
23532
23529
24531
25031
25033
24532
23533
2000 EOT
21022
23031
23528
23526
24525
25027
25029
24531
24530
24029
24530
24034
A very
Point
CN
0858 EOT
25722
27329
1450 EOT
24617
27217
29315
30317
MIT-
Boston
MA
1000 EOT
26315
27313
25620
25354
1350 EOT
05910
1501 EOT
09408
07409
West
Springfield
MA
0900 EOT
22407
28019
29017
29118
28220
27822
27229
26128
25328
1500 EOT
27119
26812
25410
22406
24808
25212
25517
Putnam
CN
0900 EOT
23715
1500 EOT
24707
23710
24112
25713
26617
aThe first three numbers indicate wind direction in degrees; the last two, wind speed in knots.
31
-------
Figure 5-1. Geographic location of rawinsonde and PIBAL stations.
32
-------
Table 5-3. FLIGHT LOCATIONS AND METEOROLOGY
Date
Battelle flight
Washington State University flight
Surface synoptic situation
over southern Region I
850-mb flow
(12Z£)
7/TS-
7/18
7/19
7/20
7/21
7/22
7/23
7/24
Evening-normal
Evening-normal
a.m.-Long Island-NYC
p.m.--Long Island-NYC
a.m.--normal
p.m.-normal
p.m.-Atlantic Ocean
(downwind Boston)
p-.m.»Long> IsJand Sound
Early p.m.-spiral at mouth of
Connecticut
late p.m.-East Connecticut
a.m.-Long Island Sound & West
Connecticut
p.m.-normal (old)
p.m.-Long Island Sound
a.m. - p.m.-normal
p.m.-Long Island Sound-Conn. R.
a.m.-Long Island Sound
p.m.-Long Island Sound
a.m.--normal
p.m.-Long Island Sound
& W. Conn.
a.m.-normal
p.m.-normal
7/25
7/26
7/27
7/28
7/29
7/30
a.m.-normal
p.m.-normal
a.m.-normal
p.m.-normal
a.m.-Hudson River
of normal
a.m.-normal (cw)
p.m.-normal (cw)
a.m.-normal
p.m.-normal
a.m.-normal
p.m.-normal
a.m.-LI Sound
p.m.--LI Sound
a.m.-normal
p.m.-normal
Night south of Boston
Weak front N-S in Wast of
| Rfegamr; SCTO flu 5RRHQNI demote
(BMffir annaine atKfc, ttriojh prasBiuw
TK^fe imcwtnji 'im from «B£tt
High pressure ridge south of
Region; SW surface flow OVC
eastern portion of Region
Same as 18th; clouds SCTD to
BRKN over entire Region
Cold front to NW moving E;
surface flow S thru SW; OVC
over most of Region
Cold front just off Region
coast; surface flow W; SCTD
clouds over region
High pressure center over
Ohio; surface flow mixed;
SCTD clouds over Region
High centered over Maryland;
cold front to NW moving E;
surface flow SW; clouds SCTD
to BRKN over Region
Low centered to NW with
frontal system moving E;
surface flow S thru SW,
clouds BRKN to OVC over
Region
Cold front N-S on west bound-
ary of Region I moving E; sur-
face flow SW; OVC over Region
High pressure centered over
Ohio; surface flow NW thru W;
SCTD clouds over Region
Cold front to W; hurricane to
SE; surface flow E; SCTD
clouds over Region
Cold front N-S in center of
Region moving E; surface flow
SW to E of front, W behind;
clouds SCTD to BRKN over
Region
High pressure centered over
West New York; surface flow
NW; skies CLR to SCTD
High pressure over E Penn.;
surface flow W: skies CLR
SSW, 30K
SW, 15K
SW, 25 K
SW, 30 K
Trof over
region, NW
thru W, 20K
WthruSW,
20 K
WNW, 20 K
SW, 20 K
NW thru W,
20 K
VRBL, 5K
W, 20K
W, 20K
NNW, 10K
33
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Table 5-3 (continued). FLIGHT LOCATIONS AND METEOROLOGY
Date
Battelle flight
Washington State University flight
Surface synoptic situation
over southern Region I
850-mb flow
(12Z5U
7/31
8/1
8/2
8/3
8/4
8/5
8/6
Return to Ohio
Rain
a.m.--plume tracking
(power plant)
a.m.-New York City
p.m.-South of Boston-Cape Cod
night-South of Boston-Cape Cod
Noon-normal
Rain
p.m.--LI Sound
a.m.--downwind-Boston
p.m.--downwind- Boston
High pressure center oveFSW
Penni; surface flow W; clouds
BRKN.
High pressure centered over W
Penn.; trof off Mass, coast;
surface flow VRBL, 5K; SKTD
^to" BRKN clouds
High pressure ridge S-N W of
Region I; surface flow VRBL,
5K; clear skies
Back door cold front N-S
thru center of Region I;
surface flow VRBL, 10K;
clouds BRKN to OVC
Small high pressure ridge
N-S, E of Region I; surface
flow E, 10K; clouds BRKN to
OVC over Region I
Occluded front N-E E of
Region; cold front N-S of
Region; surface flow VRBL,
5K; clouds SCTD over Region
NE, 20K
N thru NE,
20K
NW, 5K
SW, 10K
NW, 10K
34
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6. OZONE AND OTHER POLLUTANTS MEASURED BY THE
ENVIRONMENTAL PROTECTION AGENCY, LAS VEGAS,
DURING THE 1975 NORTHEAST OXIDANT
TRANSPORT STUDY
George W. Siple
Environmental Monitoring and Support Laboratory
U.S. Environmental Protection Agency
Las Vegas, NV
The participation of the Environmental Monitoring and Support Laboratory at Las
Vegas in the Northeast Oxidant Transport Study was a two-fold measure. First, we
provide a field meteorologist, Mr. Karl Zeller, who was responsible for day-to-day
coordination of the various airborne monitoring teams. Second, we gathered exten-
sive air quality data utilizing the Long Range Air Monitoring Aircraft (LORAMA) , often
referred to as the B-26. This paper deals with the operational capabilities of the
LORAMA and its application in the study during the summer of 1975.
First is a discussion of the system of instrumentation on board the aircraft. For
the purpose of this study, we monitored a number of pollutant and meteorological
parameters. During each flight, ozone was measured by the gas-phase chemilumi-
nescent Bendix 8002, which has proven to be a stable and precise ozone analyzer. In
addition to the Bendix analyzer, a Dasibi 1003-AAS, based on the absorption of light
by ozone, was on line during several of the later flights to aid in evaluating the equiv-
alency of the two methods under field conditions. Nitric oxide was measured on a
single-channel TECO 14B gas-phase chemiluminescent analyzer, modified for high
sensitivity. This particular instrument is designed to reliably measure oxides of ni-
trogen in the range of 0 to 5 ppb, full scale. Temperature, dewpoint, altitude, and
position were automatically recorded on a routine basis. Grab bag samples were
taken on most days, at strategic points in the flight patterns: mainly in regions of
elevated ozone values. An MRI integrating nephelometer was installed to measure
particulate matter^according to its light scattering properties. The nephelometer is
provided with a heating element that reduces the moisture content of the sample air
when the flow rate is approximately 10 to 15 cfm. The installation of the nephelome-
ter in the EPA-LV aircraft is designed for ram air to flow through the instrument,
providing a flow rate as much as ten times that which affords optimum operation of
the air drying mechanism. This vitiates the effectiveness of the heater; that is, the
heater is unable to sufficiently dry the sample air entering the nephelometer. For
that reason, the reported values essentially correspond to "wet bscat."
Prior to the study, both the Bendix 8002 and the TECO 14B were tested for sta-
bility under conditions of changing temperature and pressure, simulated in an en-
vironmental chamber at the Las Vegas lab. These tests sought to isolate the degree
of baseline shift and gain shift corresponding to the changing ambience of an unpres-
surized aircraft. Under conditions of changing temperature at constant pressure, the
only notable result was the zero level shift of the TECO. Under conditions of chang-
ing pressure at constant temperature, the notable results concern the span shift of
both the Bendix and TECO.
In the field, calibration was performed on all instruments before and after each
day's flights, checking both zero and span levels. During each flight, periodic zero
35
-------
level checks were also performed. These calibration data, along with the correction
factors derived from the environmental chamber tests, were incorporated into the
program used to process the data from the raw voltage values into the reported engi-
neering units. We now have the system capabilities for the LORAMA field team to pro-
cess data within 24 hours of collection, i.e. , while still in the field. This is a great
advantage for quality control considerations and for rapid initiation of data interpre-
tation . A copy of this process data has been presented to EPA Region I and a copy to
Joe Bufalini of EPA, Research Triangle Park, NC.
After the data were processed, they were reduced into visual representations to
aid in the analysis. This has taken two general forms, and I would like to illustrate
examples of both kinds. First, are the spatial ozone distribution maps constructed
from flights made during the study. Figures 6-1 and 6-2 are two examples of flight
patterns flown by the B-26. In these flights, the area of principle concern was that
west of New York and south of Boston. These maps show time of day and instanta-
neous ozone values. The instantaneous values are good approximations of longer-
term averages, except where values are rapidly changing.
The second type of visual representation is the vertical profile made for each pol-
lutant and meteorological parameter measured by the B-26 aircraft. Examples of these
types of measurements are given in Figure 6-3. These types of data representations
can be produced while still in the field, within a day of the data collection time.
Finally, here are a few comments on our quality assurance program. Figure
6-4 shows the traceability of the ozone calibration standard from the Federal Register
standard calibration reference method to the field monitor. Because of its stability,
the Dasibi instrument was chosen to transfer this standard to the Bendix analyzer.
As I mentioned before, a calibration was performed daily, after each flight and
before the next. A Bendix 8851-X Dynamic Calibration System was used to generate
ozone for span calibration. The Dasibi was used to measure this span value and al-
so to check the quality of the zero air. The Bendix ozone analyzer has been shown
to be a stable instrument. However, experience has shown it to be good practice to
calibrate frequently, especially when the instrument is subject to a stressful air-
craft environment, to minimize spurious data.
On August 12, all three aircraft participated in a concomitant flight. Review of
the data indicates that the LORAMA ozone data are approximately 15 percent lower, on
the average, than those ozone values measured by the other aircraft. At this time, we
have not isolated the reason for this discrepancy, but we are looking into it further.
36
-------
1442 EOT
82
168
99
1550 EOT
148
200
147
150
147
Figure 6-1. Flight pattern and ozone results (in ppb) for afternoon flight of August 14, 1975.
37
-------
NAUTICAL MILES
Figure 6-2. Flight pattern and ozone results (in ppb) for afternoon flight of
August 27, 1975.
6
X
£
ui- 4
j 3
2
1
SEA
LEVEL
J I II ]__
1 I I 1 I"
JNITRICTI I I
^OXIDE OZONE
DEW POINT OUTSIDEAMBIENT I
TEMPERATURE TEMPERATURE '
i i i i i i r
SCATTERING
COEFFICIENT,
3 0 20 40 60 80-10
CONCENTRATION, ppb
0 10 20
TEMPERATURE, °C
30
Figure 6-3. Vertical profiles of various pollutant and meteorological
variables measured by the B-26 aircraft.
38
-------
GPTWITHNBS
NO CYLINDER
If I FPRPRAI
REGISTER METHOD
PERFORMED AT
EPA-LAS VEGAS
ULTRAVIOLET
PHOTOMETER
EPA-LAS VEGAS
LAS VEGAS
Pre-Oxidant Study
LABORATORY-
BASED DASIBI
INSTRUMENT
BOSTON
August 1975
BOSTON OXIDANT
STUDY DASIBI A AS
CALIBRATION
INSTRUMENT
(DAS B-26)
DASIBI B-26
CALIBRATION
INSTRUMENT
B-26BENDIX03
INSTRUMENT
AMBIENT AIR
LAS VEGAS
Post-Oxidant Study
LABORATORY-BASED
DASIBI INSTRUMENT
A.—
ULTRAVIOLET
PHOTOMETER
EPA-LAS VEGAS
Figure 6-4. EPA - Las Vegas field calibration scheme.
39
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7. PRELIMINARY RESULTS OF HYDROCARBON AND OTHER
POLLUTANT MEASUREMENTS TAKEN DURiNG THE 1975
NORTHEAST OXIDANT TRANSPORT STUDY
William A. Lonneman, Robert L. Seila, and Sarah A.
Environmental Sciences Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC
Meeks
The location of the EPA-RTP mobile laboratory during the 1975 Northeast Study
was at Chickatawbut Hill (elevation 517 feet) located in the Blue Hills reservation
near Quincy, approximately 10 miles south of downtown Boston, MA. The laboratory
was fully equipped to continuously measure many gaseous pollutant concentrations as
well as several meteorological variables. The equipment array is listed in Table 7-1.
In addition to these continuous measurements, Cl-ClQ. hydrocarbon compositional de-
terminations were made by gas chromatographic procedures 1 for bag samples collect-
ed by aircraft and at selected ground sites. The aircraft bag samples analyzed were
primarily those collected by the EPA-LV B-26 aircraft; however, on occasion, some
aircraft samples collected by Washington State University and Battelle were analyzed.
Table 7-1. MOBILE LABORATORY INSTRUMENT ARRAY
Pollutant
Instrument
Ground samples were col-
lected at four ground sites in-
cluding the Chickatawbut loca-
tion. For these studies, 2- and
3-hour integrated bag samples
were collected with an automat-
ed sampler at two sites simul-
taneously over a 24-hour period.
The other ground sites included
the 2 5th floor of J . F . K. Feder-
al Building in downtown Boston,
the second floor of the science
building on the campus of the
Essex County Industrial Farm in
Danvers, MA, approximately 25
miles northeast of downtown Bos-
ton , and a penthouse room at the
Massachusetts State Mental Hos-
pital in Medfield, MA, approxi-
mately 25 miles southwest of
downtown Boston . Ozone-meas-
urements were also made at each of these sites during the field study sample period.
Ground samples were also collected in the Sumner and Callahan tunnels and along
downtown highway locations in an effort to determine auto exhaust composition and
hydrocarbon to acetylene ratios .
The study period commenced on July 17 and extended to August 29, 1975. The
following tables and figures of data are intended to represent some of the preliminary
findings of this study.
Nitrogen oxides
Total hydrocarbon, methane,
carbon monoxide
Total sulfur
Ozone
PAN
Freon-11, carbon tetrachloride
Visibility
UV-visible radiation
Wind speed and direction
Temperature - relative humidity
TECO 14B
Beckman 6800
Meloy SA-120
Bendix model 8002
G.C.-electron capture
G.C.-electron capture
MRI-integrating nepholometer
Eppley radiometer
Bendix aerovane system
Hydrothermograph
40
-------
Table 7-2 represents the average percentage composition of the total hydrocar-
bons for the sum of the identified olefins, paraffins, and aromatic compounds for
the bag samples collected during the 600 to 900 and 1500 to 1800 time periods at each
of the ground sites. The average percentage acetylene of the total hydrocarbon is al-
so included. The JFK data were excluded from this comparison since paint vapor
contaminates of the heavy molecular weight hydrocarbon variety dominated the
composition.
Although this percentage representation has limited usefulness, three observa-
tions can be made:
1. The general consistency in the composition between the three ground sites.
2. Sources of hydrocarbon other than vehicular tailpipe emissions at the ground
sites are evident by the lower percentage of acetylene compared to the tunnel
samples. These other hydrocarbons are obviously paraffins and aromatics.
3. Some photochemical loss of the olefinic hydrocarbons is suggested at both sam-
ple time intervals. This is concluded by the comparison of the ratio of the
percent of sum of olefins to percent of acetylene between the ground and tun-
nel sites.
Table 7-2. COMPARISON OF HYDROCARBON COMPOSITION
AT GREATER BOSTON AREA GROUND SITES TO ROADWAY
AND TUNNEL SAMPLES, 1975
(percent)
0600-0900 hours
Paraffins
Olefins
Aromatics
Acetylene
1500- 1800 hours
Paraffins
Olefins
Aromatics
Acetylene
Tunnel and
roadway
48
20
32
5.1
48
20
32
5.1
Chickatawbut
52
09
39
3.1
63
08
29
2.7
Danvers
58
09
33
3.1
50
07
43
3.3
Medfield
58
09
33
3.6
50
10
40
2.6
Figure 7-1 represents the diurnal variation of the sums of olefins, paraffins, and
aromatics for July 18, 1975. It is apparent that sources other than tailpipe emissions
contribute to the total hydrocarbon burden by the inconsistency between the diurnal
patterns. During the 0300 to 1000 time period, other paraffin sources are evident,
primarily at the expense of the sum of aromatics. This trend reverses during the
1000 to 1700 period. The composition becomes consistent for the remaining time per-
iods . The olefin composition is fairly consistent throughout the day, with some indi-
cation of olefin loss during the 0900 to 1500 time period.
41
-------
70
« 60
1 50
cc
u
o
CC
40
30
5
O
z
20
O
10
i. PARAFFINS
i. AROMATICS
0200 0400 0600 0800 1000 1200 1400
TIME, hour of day
1600
1800
2000
2200
2400
Figure 7-1. Diurnal variation of 2 paraffins, 2 aromatics, and 2 olefins as percentage of total
nonmethane hydrocarbons, Chickatawbut Hill, July 18, 1975.
Some natural hydrocarbons of the terpene variety have been observed to elude
from our gas chromatograph columns at retention times similar to peaks identified as
vehicular type hydrocarbons. Two such examples are shown in Figure 7-2. In the
top figure, diurnal patterns of 1,2,4-trimethylbenzene and m- and p-ethyltoluene
are plotted. In the tunnel and roadway samples, these two peaks were generally at
equal concentrations; however, this is not the case at the Chickatawbut site for this
particular day's study. It appears that other sources of either 1,2,4-trimethylben-
zene or another compound occur during each sample period, especially during the
1100 to 1700 and 1700 to 2100 time periods. In previous studies, d-limonene was
found to have a similar retention time to 1,2,4-trimethylbenzene. It is merely specu-
lative to assume that the difference between these two curves is d-limonene, since
the half life of this compound in the presence of 100 ppb ozone is approximately 3
minutes; however, it is doubtful that this peak is entirely 1,2,4-trimethylbenzene.
Another similar example is presented in the lower plot of Figure 7-2. In th - tun-
nel and roadway samples, a consistent 3 to 1 ratio was observed for the ratio of car-
bon concentration of 2-methylpentane to cyclopentane. This ratio was observed at
the Chickatawbut Hill site in the early morning hours; however, during the 0800
through 2300 time period, the cyclopentane peak becomes the more abundant peak.
During the afternoon, this peak is approximately 30 ppb carbon larger than expect-
ed. The only identified compound with a similar retention time to cyclopentane is
isoprene. The general area at the Chickatawbut Hill site is surrounded by woodland
vegetation, which may explain these unusual peak ratios. Red Oak trees are common
to the area and are known emitters of isoprene, especially during daylight hours.
The ozone levels during these afternoon hours exceeded 100 ppb.
42
-------
211
181
15
12
9
6
3
I 0
o
CD
a:
o 35
1,2.4-TRIMETHYL BENZENE
d LIMONENE
m.p.ETHYL TOLUENE
30
25
20
15
10
5
CYCLOPENTANE (ISOPRENE)
0000 0200 0400 0600 0800 1000 1200 1400 1600 1800 2000 2200 2400
TIME, hour of day
Figure 7-2. Diurnal variation of hydrocarbon compounds, Chickatawbut Hill, July 18, 1975.
The mercuric sulfate-sulfuric acid scrubber technique was used on other samples
exhibiting unusually high cyclopentane concentrations and confirmed that most of the
peak area was olefinic. The use of this scrubber technique on the 1,2,4-trimethyl-
benzene peak were inconclusive.
In recent years, field studies were conducted in rural atmospheres of low hydro-
carbon concentrations. During these studies, bag surface out-gassing contamination
was observed in many of the analyzed bag samples. In an effort to investigate the out-
gassing nature of the Tedlar poly vinyl fluoride film, a series of experiments were per-
formed to evaluate temperature and sunlight irradiation effects.2
The results of a 6-hour exposure of simulated sunlight on a Tedlar bag containing
zero hydrocarbon grade air are given in Figure 7-3. Several peaks that would inter-
fere with the accurate analysis of stored ambient air samples were observed on the
silica gel and dibutylmaleate columns. Interfering peaks occurred to a smaller extent
on the aromatics column.
Outgassing as a function of increased temperature was investigated by placing a
Tedlar bag filled with zero hydrocarbon grade air in a large drying oven at 50°C for
several hours. A temperature of 50°C (122°F) was chosen as a maximum expected
ambient air temperature.
It was observed that increased temperature resulted in little or no significant peak
interference on the silica gel or dibutylmaleate columns; however, similar peaks
43
-------
TYPICAL CHROMATOGRAMS OF HYDROCARBON-FREE AIR IN PVF BAG
J
J
DIBUTYL MALEATE COLUMN,
C-4 TO C-9 PARAFFINS
ANDOLEFINS
SILICA GEL COLUMN,
C-2 TO C-4 HYDROCARBONS
m-bis-m-PHENOXYPHENOXY
BENZENE COLUMN,
AROMATICS
Figure 7-3. Typical chromatograms of hydrocarbon-free air in Tedlon bag irradiated by
simulated sunlight for 6 hours.
44
-------
observed during the irradiation studies on the aromatics column were observed dur-
ing these studies but at significantly higher concentrations. In fact, the last peak on
the aromatics chromatograph was identified as dimethylacetamide, the solvent used
in the extrusion process for making Tedlar film.
It was concluded from these studies that the outgassing peaks observed on the
silica gel and dibutylmaleate columns were the result of photochemical degradation,
whereas, the peaks observed on the aromatics column were the result of temperature
desorption. It was also concluded that Tedlar bags could be used for these studies
as long as they were covered with black polyethylene to block out sunlight and stored
at reasonable ambient temperatures.
Representative diurnal patterns of ozone and other pollutions at the Chickatawbut
Hill site are given in Figures 7-4 to 7-7. Figures 7-4 and 7-5 represent those days in
which double ozone peaks were observed during the 24-hour sampling period. The
first ozone peak occurs during the early afternoon hours and could be representative
of the photochemistry of local area emissions. This contention is somewhat indicated
by the typical early morning buildup of vehicular emissions observed by the increase
in acetylene during the 0600 to 0900 time period (Figure 7-4) and the 0800 to 1000 in-
crease of carbon monoxide (Figure 7-5) .
0.
z"
o
EC
O
u
LU
a
CC
IS
120
110
100
90
80
70
60
50
40
30
20
10
JULY 18 JULY 19
WIND SPEED: 7 mph 11 mph
WIND DIRECTION: 240° 240°
I
o
K
cc
u
Z
o
u
o
u
1.5
1.0
0.5
cc
O
0100
0600
1200
JULY 18,1975
1800
2400
TIME OF DAY
0600
1200
JULY 19,1975
1800
2400
Figure 7-4. Diurnal hourly concentrations of ozone, carbon monoxide, acetylene, and visi-
bility, Chickatawbut Hill, July 18 and 19, 1975.
The second ozone peak appears during the late evening hours and was obviously
the result of transported ozone from southwest locations in the case of Figure 7-4 and
from west to northwest locations in the case of Figure 7-5. The geographical origin
of this ozone is difficult to predict, but from ground wind speed considerations, the
distance was probably 50 to 100 miles. This distance would be longer if one also con-
sidered early morning ozone precursor transport. In Figure 7-4, corresponding in-
creases of acetylene and PAN during the nighttime ozone peak indicate its anthropo-
genic origin.
45
-------
<
cc
o
u
LU
a
<
OC
LU
<
>
«J
oc
3
o
110
100
90
80
70
60
BO
40
30
20
10
AUG.21 AUG. 22
WIND SPEED: 4.7 mph 5.1 mph
WIND DIRECTION: 310° 270°
1.5
1.0
0.5
0600 1200
AUGUST 21, 1975
1800
2400
TIME OF DAY
0600 1200 1800
AUGUST 22,1975
2400
Z
O
o
u
o
o
UJ
a
o
110
100
90
80
70
60
50
40
30
20
10
JULY 28 JULY 29
WIND SPEED: 6.6 mph 5.0 mph
WIND DIRECTION: 250° 325°
1.5
1.0
0.5
2400 0600 1200 1800
JULY 28,1975
2400
TIME OF DAY
0600 1200 1800
JULY 29,1975
2400
o
o
o
CO
ac
LU
>-
—1
oc
o
Figure 7-6. Diurnal hourly average concentrations of ozone, nitric oxide, nitrogen dioxide, and
carbon monoxide, Chickatawbut Hill, July 28 and 29, 1975.
46
-------
<
cc
o
u
LU
a
EC
3
O
JULY 23 JULY 24
WIND SPEED: 5.3 mph 8.9 mph
WIND DIRECTION: 270° 225°
0600 1200 1800
JULY 23,1975
2400
TIME OF DAY
0600 1200 1800
JULY 24,1975
2400
Figure 7-7. Diurnal hourly average concentrations of ozone, nitric oxide, and nitrogen dioxide,
Chickatawbut Hill, July 23 and 24, 1975.
Figure 7-8 and 7-9 represent comparison plots of ozone and carbon monoxide for
the Chickatawbut Hill and J.F.K. Federal Building sites. In effect, the plots repre-
sent ozone patterns of urban and suburban ozones. Figure 7-8 in particular repre-
sents what has typically been described as the so-called "urban effect"; that is, the
suppression of ozone by fresh emissions of nitric oxide from vehicular sources. High-
er vehicular emissions at the urban site are obvious by the comparison of the carbon
monoxide patterns. The tendency of fresh vehicular sources is to suppress ozone in
the urban areas and produce high ozone concentrations downwind of the urban complex,
In Figure 7-9, the ozone maximum at the J.F.K. site is approximately the same mag-
nitude as that observed at the Chickatawbut Hill site; however, it occurs later in
the afternoon and was probably the result of a transported air mass.
Figure 7-10 represents the frequency distribution of time versus high hourly av-
erage ozone concentrations at the Chickatawbut Hill site. High ozone concentration is
defined as 80 ppb or higher. There were a total of 99 high hourly average ozone con-
centrations observed during this study, which represented 8.8 percent of all of the
hourly average measurements made. This 8.8 percent is lower than the 13 to 14 per-
cent observed at the various rural sites during the 1974 Midwest study3 and consider-
ably lower than the 20 to 30 percent observed during the 1973 Midwest study.4 Since
all three of these studies were conducted during similar summertime seasons, the dif-
ferences were probably due to meteorological variations. Although the data are not
presented here for comparison, the high pressure systems moving through the north-
east were faster and less stable than the highs moving through the midwest during the
1973 and 1974 seasons.
Approximately 29 percent of the high ozone averages were observed during the
nighttime hours from 0000 to 0500 and 1900 to 2400. Since the formation of ozone from
photochemical processes is for all purposes zero during these time intervals, these
high ozone levels were the result of transported air masses.
47
-------
(240-270)
130
WrND DIRECTION, compass degrees ,
, (7-8)
WIND SPEED, mph
(300-330)
J
— (2-31
0000
0200
0400
0600
0800
1000 1200 1400
TIME, hour of day
1600
1800
2000
2200
Figure 7-8. Comparison of JFK Building with Chickatawbut Hill, July 31, 1975.
- (300-320)
WIND DIRECTION, compass degrees
t (3-4)
WIND SPEED, mph
.(350)
-»-j-*(2
-------
12 —
10
CO
z
o
< 8
oc
LU
co
m
0 K
u. 6
O
LTU
* 80 ppb OR ABOVE
TOTAL OBSERVATIONS = 99
n
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
TIME OF DAY
Figure 7-10. Frequency distribution of time versus high * hourly average ozone concentrations.
Approximately 13 percent of these high ozone hourly averages occurred on week-
ends; that is, Saturday and Sunday. Since weekend days represent 26 percent of the
total week period, one can conclude that the so-called "week-end effect" was not ob-
served at this site during the study period. The "weekend effect" is described as
higher weekend ozone concentrations than week days due to higher HC/NOX ratios
and more favorable NC>2/NO ratios for earlier ozone formation. The J.F.K. sites, or
in general urban sites, are more likely candidates to demonstrate "weekend effects";
however, these data have not yet been analyzed.
Figure 7-11 represents the frequency distribution of wind direction versus high
hourly average ozone levels. The nighttime or darkened areas represent the time
periods of 1700 to 2400 and 0000 to 0500. It is obvious that most of the high hourly
average ozone concentrations were observed when the winds were generally from the
west, in particular the southwest. Practically all (90 percent) of the nighttime high
hourly average ozone observations occurred when the winds were from the southwest.
Table 7-3 represents some of the detailed hydrocarbon and corresponding ozone
data collected by the EPA-Las Vegas aircraft during the study period. Included in
the table are ranges of various results for all the flights during the study period as
well as the range of various data for the flight when both the highest and lowest ozone
were observed. The August 28 flight was performed to measure background levels
for ozone and hydrocarbons in the area of Eastport, ME. There has been some inter-
est in the construction of a petroleum refinery in this general area. It can be seen
from the table that most of the low hydrocarbon and ozone.measurements observed
during the entire study were made during this particular flight. Occasionally high
concentrations of ethane and propane were observed in some of these samples, even
though the methane concentrations were not unusually high. The origin of these high
concentrations are difficult to explain, although the only two known sources are ei-
ther natural gas leaks or geological emissions from oil fields. The aromatic and
49
-------
45
40
co 35
O
E 30
LU 25
£ 20
O
LU 15
OQ
1 10
NIGHT
DAY
TOTAL OBSERVATIONS = 99
NE
E SE S SW
WIND DIRECTION
W
NW
Figure 7-11. Frequency distribution of wind direction at times of high
ozone levels.
Table 7-3. AIRCRAFT SAMPLES TAKEN AUGUST 11-28, 1975 -
BOSTON OXIDANT STUDY (RANGE OF OBSERVATIONS)
Acetylene, ppbC
Sum of paraffins, ppbC
Sum of olefins, ppbC
Sum of aromatics, ppbC
Sum of NMHC, ppbC
Ethane + propane, ppbC
Ozone, ppb
August 14
1.0- 7.1
17.3- 84.1
4.4- 11.6
23.3- 47.7
53.1 - 195.0
10.5- 47.9
53 - 186
August 28
0.2- 0.5
8.9-195.7
0.3 - 9.0
5.4- 13.7
17.0-211.2
3.9- 164.7
27 - 30
All samples
0.2- 7.1
8.6 - 244.2
0.3- 14.5
5.4- 53.2
17.0-267.7
2.5- 164.7
27 - 186
paraffinic hydrocarbons represent, as expected, the largest fractions of total non-
methane hydrocarbon.
Table 7-4 represents the ratio or normalization of the sums of the hydrocarbon
types to acetylene. By comparison of these ratios to those measured in the tunnel
and roadway samples, additional sources of hydrocarbons other than vehicular emis-
sion, as well as the photochemical loss of the reactive hydrocarbons, can be observed.
50
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Table 7-4. AIRCRAFT SAMPLES TAKEN AUGUST 14, 1975 - BOSTON OXIDANT STUDY
Sample
No.
1
2
3
4
5
6
7
Roadway
Ground
level
Ozone,
ppb
87
108
160
186
104
119
53
C2H2,
ppbC
2.2
2.1
5.0
7.1
2.1
3.8
1.0
2 P/C2H2
10.5
19.4
13.7
12.0
17.8
11.5
17.3
8.9
2 A/C2H2
10.6
23.0
7.0
7.5
15.4
7.8
20.0
6.0
2 0/C2H2
2.4
2.5
2.3
1.4
2.2
1.7
4.0
3.6
Dimethyl
acetamide,
ppbC
77.9
52.3
51.0
363.6
152.2
105.9
77.3
18-25
In each of the aircraft samples, the I PlC-^2 were higher than those observed in the
roadway samples. These higher ratios are generally observed in urban and subur-
ban atmospheres and are usually attributed to gasoline spillage and evaporative
sources. Ethane and propane were included in these calculations, and in some of
these samples the high I P/C2H2 ratios observed were due to those two paraffins. A
more accurate calculation would be to exclude these two compounds from consideration.
The £ A/C2H2 observed in these aircraft samples were higher than those observed
along the roadway. Industrial and gasoline sources may be partly responsible for
these higher ratios; however, unknown peaks, possibly from the surfaces of the Ted-
lar bag, interfere with an accurate summation. Additional surface outgassing is indi-
cated by the extremely high concentration of dimethylacetamide, the solvent used in
the extrusion process of Tedlar, These concentrations were two to twenty times high-
er than those observed in ground level bag samples and are probably the result of the
higher ambient temperature in the aircraft. The Z O/C2&2 ratios, with the exception
of bag 7, were lower than the roadway ratio, indicating photochemical loss.
In an effort to evaluate corresponding hydrocarbon data with observed ozone lev-
els during the Northeast Oxidant Transport Study, correlations of hydrocarbons with
ozone were performed. Some obvious comparisons were investigated, including the
comparison of the ratios of reactive hydrocarbons to acetylene with ozone in an effort
to determine whether observed ozone levels correlated with reactive hydrocarbon loss.
These relationships were not that obvious since prior knowledge of the air mass, such
as initial absolute concentration levels and HC/NOX ratios, is necessary.
In an effort to investigate urban tracer relationships to ozone, acetylene and cor-
responding ozone data were assembled for aircraft samples. The acetylene and ozone
for each individual flight appeared to have a linear relationship, especially for flights
over the Atlantic Ocean during afternoon and later afternoon time periods. For this
reason, correlations of acetylene versus ozone were performed by setting acetylene
as the independent variable and ozone as the dependent variable. Linear regression
equations were also determined. The results of these exercises are recorded in
Table 7-5.
51
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Table 7-5. CORRELATION OF OZONE VERSUS ACETYLENE FOR EPA-LV AIRCRAFT
SAMPLES - BOSTON OXIDANT STUDY, 1975
Sample
period
August 14
August 20
August 27
All samples
Observations
7
7
6
66
P
0.91
0.95
0.87
0.85
Slope
19.6
15.9
29.9
19.4
Intercept
46.1
38.1
20.7
31.0
Os range,
ppb
53-186
40- 69
58-
29-186
C2^2 range,
ppbC
1.0-7.1
0.3- 1.5
1.6-2.6
0.2-7.1
Slopes and intercepts in the regression equations are reasonably comparable, as
might be expected since emissions and meteorological parameters are expected to be
consistent during this short study period. Differences in slopes may be due to the
variation of absolute hydrocarbon and nitrogen oxides concentrations, HC/NOX ratio,
temperature, sunlight intensity or, in general, the chemical and physical parameters
that control the photochemical reaction mechanism.
The intercept could represent background ozone or a condition where auto ex-
haust contribution is zero, since acetylene is equal to zero. The ozone in these in-
stances would be the result of hydrocarbon and nitrogen oxides emissions from other
anthropogenic sources such as power plants, gasoline evaporative and spillage emis-
sions, and other industrial sources, along with natural background emissions for
this particular area.
During the 1974 Midwest Oxidant Transport Study, an urban plume of high ozone
was transported into Wilmington, OH, from the general direction of Dayton on July 18.
On this particular day, the afternoon ozone increased to 0.20 ppm, a factor of two in-
crease in the ozone concentration. The acetylene levels were also the highest ob-
served during the entire study. The step increase in ozone was associated with a
similar increase in acetylene. For this reason these two components were correlated
and a linear regression curve established. The result were a slope of 15.4 and an in-
tercept of 38 with a correlation coefficient of 0.90 for six data pairs. These values are
comparable to those obtained for Boston.
Acetylene and ozone seem to be likely candidates for this type of mathematical
treatment since acetylene is representative of automotive emissions - the most abun-
dant source of photochemical smog precursors.
It must be understood that extrapolation of these linear regression equations to
points other than actual data pairs are purely speculative. This exercise, however,
is extremely interesting since background levels of ozone predicted by these calcula-
tions are comparable to actual experimental observations such as the 30 ppb ozone
measurements made over Maine during the flight of August 28, 1975. The correspond-
ing acetylene levels for these hydrocarbon samples ranged from 0.2 to 0.5 ppb
acetylene.
52
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REFERENCES
1. Lonneman, W.A., S.L. Kopczynski, P.E. Darley, andF.D. Sutterfield. Environ,
Sci. Technol. 8:229, 1974.
2. Seila, R.L., W.A. Lonneman, andS.A. Meeks. Environ. Letters. Vol. II.,
No. 2, 1976.
3. Investigation of Ozone and Ozone Precursor Concentrations at Nonurban Loca-
tions in the Eastern United States. U.S. Environmental Protection Agency Pub-
lication EPA-450/3-74-034. p. 1-39. 1974.
4. Investigation of Rural Oxidant Levels as Related to Urban Hydrocarbon Control
Strategies. U.S. Environmental Protection Agency Publication EPA-450/3-75-036.
p. 57. March 1975.
53
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8. TRENDS IN OZONE LEVELS
IN SOUTHERN NEW ENGLAND FOR 1975
Donna D . Morris and Arnold L . Leriche
U.S. Environmental Protection Agency, Region I
Boston, MA
This presentation will summarize observed photochemical oxidant concentrations
in Connecticut, Massachusetts, and Rhode Island for April through September 1975
and discuss some interesting trends observed during the months of July and August
(the Northeast Oxidant Transport Study was conducted July 15 through August 28,
1975) . Data were collected at state-operated monitoring stations using continuous
chemiluminescent ozone monitoring instruments. These data are recorded in the
SAROAD system. Eastern standard time was used in all cases.
The locations of ozone monitoring stations are shown on the map of southern New
England (Connecticut, Massachusetts, and Rhode Island) in Figure 8-1. In 1975, 14
monitoring stations were operated by Connecticut (Derby was not operational), 21 by
Massachusetts, and 2 by Rhode Island. The letters (A-D) show the locations of the
special monitoring stations for the summer oxidant study as follows: A—Environmen-
tal Protection Agency, Research Triangle Park, at Quincy; B—Washington State Uni-
versity at Groton; C—Battelle at Simsbury; and D—Harvard School of Public Health
at Watertown. Table 8-1 describes the locations and instrumentation for the state
ozone monitoring stations.
'Figure 8-1. Location of ozone monitoring stations operating in southern
New England during 1975 Oxidant Transport Study.
54
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Table 8-1. MONITORING SITES
City
1. Greenwich
2. Stanford
3. Bridgeport
4. Danbury
5. Derby
6. New Haven
7. Hamden
8. Middletown
9. Hartford
10. Torrington
11. Windsor
12. Enfield
13^ Eastford
14. Groton
15. Litchfield
Connecticut sampling sites
Location
Bruce Golf Course
Trailer at Health Department
Barnum Avenue, Housatonic
Community College
W. Connecticut State College
Flood control dam (not operational
1975)
Agricultural experimental station
Agricultural experimental station
City Hall
State office building
Franklin Avenue
Agricultural experimental station
Kosciusko School
Natchaug State Forest
Fort Griswold
Morris, Route 109
Local environs
Rural
Urban
Urban
Suburban
Urban
Suburban
Rural
Urban
Urban
Urban
Rural
Suburban/rural
Rural
Suburban
Rural
Massachusetts sampling sites
1. Salem
2. Cambridge
3. Quincy
4. Framingham
5. Fall River
6. Fitchburg
7. Worcester
8. Chicopee
9. Amherst
10. Pittsfield
11. Medford
12. Greenfield
13. Danvers
14. Fairhaven
15. Lowell
16. Waltham
17. Waltham
18. Medfield
19. Springfield
20. Boston
21 . Boston-
New high school. Highland Ave.
Science Park
Monsignor O'Brien Highway
Fore River Bridge traffic circle
Civil Defense - Route 9
Globe Street Fire Station
Summer Street Substation
New Salem & Washington Streets
Westover Air Force Base
(operational 7-15-75)
University of Massachusetts
Dalton Ave. (state police barracks)
Wellington Circle, fits. 28 & 16
Waste water treatment facility
Essex Agricultural College
Marina - Middle Street
John Street trailer
Moody & Main Street
Beaver Street
State Hospital
E. Columbus Ave.
Kenmore Square
J.F.K. Building (25th floor)
Suburban
Urban
Suburban
Suburban/rural
Suburban
Suburban/rural
Urban
Suburban
Suburban
Suburban/urban
Suburban
Rural
Rural/suburban
Suburban
Urban
Urban
Suburban
Rural
Urban
Urban
Urban
Rhode Island sampling sites
Providence
Scituate
State Street
Scituate Reservoir
Urban
Rural
55
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Monthly maximum ozone values and frequency of violations for April through
September 1975 in Connecticut, Massachusetts, and Rhode Island are presentee in
Tables 8-2 to 8-4, respectively. Four general observations can be made regarding
these data:
1. Violations of the National Ambient Air Quality Standard for photochemical ox-
idants occurred throughout the 6-month period from April to September 1975
in Southern New England.
2. Maximum ozone levels for this period were recorded in June for all three
states.
3. Violations of the photochemical oxidant standard tended to occur most fre-
quently at rural and suburban/rural locations.
4.
Furthermore, in Connecticut and Massachusetts the photochemical oxidant
standard tended to be violated most frequently at particular locations:
a. In Massachusetts, for April through July the site with the most frequent
violations was Framingham, which is located approximately 19 miles
west of Boston.
b. In Connecticut, for May, June, and July the most frequent violations oc-
curred at Torrington or Litchfield, which are in the same general area
in northwestern Connecticut.
Table 8-2. MONTHLY MAXIMUM OZONE VALUES AND FREQUENCY OF VIOLATIONS,
APRIL THROUGH SEPTEMBER, 1975, CONNECTICUT
Site with lowest
maximum3
Site with highest
maximum3
Site with most
frequent
violations'3
Number of sites
with violations0
April
New Haven
0.050/0
Windsor
0.090/1
Eastford
3/2
4/12
May
Greenwich
0.159/11
Bridgeport
0.245/9
Torrington
38/16
11/11
June
Stamford
0.125/6
Middletown
0.325/6
Torrington
54/9
11/11
July
Windsor
0.130/11
New Haven
0.315/13
Litchfield
179/19
14/14
August
Windsor
0.095/4
New Haven
0.190/6
Groton
119/16
14/14
September
Windsor
0.070/0
Eastford
0.125/5
Hamden
5/2
7/14
aMaximum value in parts per million/number of days standard (0.08 ppm for 1 hour) exceeded.
'•'Number of violations/number of days.
cNumber of sites with violations/number of sites operational.
Figures 8-2 to 8-5 present monthly maximum and monthly average ozone concen-
trations by hour of the day (Eastern Standard Time) for July and August at selected
locations. Bridgeport (Figures 8-2a and 8~2b) was selected as generally representa-
tive of Connecticut data, particularly the urbanized areas. For both July and August,
high oxidant levels were measured in the afternoon. However, a different pattern
56
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TABLE 8-3. MONTHLY MAXIMUM OZONE VALUES AND FREQUENCY OF VIOLATIONS,
APRIL THROUGH SEPTEMBER 1975, MASSACHUSETTS
Site with lowest
maximum3
Site with highest
maximum8
Site with most
frequent
violations"
Number of sites
with violations'*
April
Springfield
0.046/0
Cambridge
0.100/1
Framingham
3/1
3/14
May
Boston
0.080/0
Amherst
0.200/10
Framingham
66/12
13/14
June
Springfield
0.060/0
Framingham
0.208/6
Framingham
32/6
12/15
July
Springfield
0.080/0
Pittsfield
0.168/7
Framingham
79/4
17/18
August
Boston
0.090/3.056/0
Fairhaven
0.75/14
Fairhaven
/14
17/17
September
Cambridge
Waltham,
Beaver St.
0.150/5
Waltham
23/5
13/17
aMaximum value in parts per million/number of days standard (0.08 ppm for 1 hour) exceeded.
"Number of violations/number of days.
cNumber of sites with violations/number of sites operational.
Table 8-4. MONTHLY MAXIMUM OZONE VALUES AND FREQUENCY OF VIOLATIONS,
APRIL THROUGH SEPTEMBER 1975, RHODE ISLAND
Site with lowest
maximum3
Site with highest
maximum3
Site with most
frequent
violations"
Number of sites
with violations0
April
No data
No data
No data
No data
May
Providence
0.125/4
Scituate
0.135/7
Scituate
50/7
2/2
June
Scituate
0.150/3
Providence
0.180/3
Scituate
22/3
2/2
July
Scituate
0.110/6
Providence
0.135/8
Providence
36/8
2/2
August
Scituate
0.095/3
Providence
0.105/7
Providence
17/7
2/2
September
Scituate
0.045/0
Providence
0.110/1
Providence
6/1
1/2
aMaximum value in parts per million/number of days standard (0.08 ppm for 1 hour) exceeded.
"Number of violations/number of days.
' cNumber of sites with violations/number of sites operational.
was observed for Eastford, CN, which is a rural site in the northeastern portion of
the state. In July (Figure 8-3a), the highest oxidant levels occurred in the late
afternoon and evening hours. The monthly average ozone curve is also skewed to-
ward the late afternoon. The pattern for August (Figure 8-3b) is not quite as pro-
nounced, but violations also occurred in the late afternoon and nighttime hours.
The departure from the standard diurnal curve for maximum ozone values tended
to be even more pronounced in Massachusetts. In Framingham (Figure 8-4a) , the
highest ozone levels during July occurred in the evening, although violations also
occurred in the morning and afternoon. As in Eastford, the Framingham pattern dur-
ing August (Figure 8-4b) is not pronounced, although the highest ozone levels oc-
curred in the late afternoon.
57
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Figure 8-2a. Monthly maximum and average ozone concentrations by hour for Bridgeport,
Conn., July 1975.
0.20
0.15
5 0.10
o
0.05
0.0
PRIMARY_STANDA_RO_
"FOR OZONE (0.08 ppm)
24
12
HOUR OF DAY
16
20
23
Figure 8-2b. Monthly maximum and average ozone concentrations by hour for Bridgeport,
Conn., August 1975.
58
-------
24
Figure 8-3a. Monthly maximum and average ozone concentrations by hour for Eastford, Conn.,
July 1975.
0.20
0.15
3 0.10
0.05 —
0.0
24
12
HOUR OF DAY
20
Figure 8-3b. Monthly maximum and average ozone concentrations by hour for Eastford, Conn.,
August 1975.
By comparing the July data for Bridgeport, Eastford, and Framingham, it is ap-
parent that the highest ozone values occurred later in the day (from midafternoon to
late evening) as one moves to the northeast. However, the monthly average ozone
concentrations by hour of the day shift very little. It is expected that this is due to
a greater frequency of daily maximums occurring in the afternoon while the highest
monthly maximums occurred during episode conditions, with winds probably from
the southwest.
59
-------
Figure 8-4a. Monthly maximum and average ozone concentrations by hour for Framingham,
Mass., July 1975.
0.20
0.15
0.10
0.05
0.0
TT I
24
12
HOUR OF DAY
20
23
Figure 8-4b. Monthly maximum and average ozone concentrations by hour for Framingham,
Mass., August 1975.
Very different patterns were observed in Litchfield, CN, a rural site approxi-
mately 25 miles west-southwest of Hartford (Figures 8-5a and 8-5b) . In July, viola-
tions of the oxidant standard were observed at all hours of the day. However, there
was a slight tendency for the highest ozone values to occur in the morning. A simi-
larly uniform pattern occurred in August, although the highest ozone values were
recorded in the late afternoon. Even more interesting are the monthly average ozone
concentrations by hour. For both July and August, the highest monthly average
ozone value occurred in the morning.
60
-------
0.20
0.15 —
|
0.10
0.05
0.0
FOR OZONE (0.08 ppm)
.AVERAGE OZONE
12
HOUR OF DAY
16
20
23
Figure 8-5a. Monthly maximum and average ozone concentrations by hour for Litchfield, Conn.,
Jujy 1975.
0.20
0.15
0.10
0.05
0.0
MAXIMUM OZONE
___
FOR OZONE (0.08 ppm)
24
12
HOUR OF DAY
16
20
23
Figure 8-5b. Monthly maximum and average ozone concentrations by hour for Litchfield, Conn.,
August 1975.
Daily maximum ozone levels for various locations in Connecticut, Massachusetts,
and Rhode Island during July and August are shown in Figures 8-6 through 8-12.
Figures 8-6a and 8-6b present the daily maximum ozone levels in Middletown, CN,
for July and August, respectively. Middletown was selected because the daily pat-
tern of ozone levels is quite representative of Connecticut monitoring sites. From
these graphs, one can readily see the days in which ozone violations were recorded
and also pick out the "episodes." Once again, the exception to the general rule in
Connecticut is the Litchfield site. The daily maximum and daily average ozone lev-
els for Litchfield in July are presented in Figure 8-7 (not enough data were available
61
-------
130
0.25
0.20
0.15
0.10
0.05' —
DAY OF MONTH
Figure 8-6a. Daily maximum ozone concentration at Middletown, Conn., July 1975.
0.20
PRIMARYJSTANDAR^
0~R OZONE (0.08 pom)
14
DAY OF MONTH
Figure 8-6b. Daily maximum ozone concentration for Middletown, Conn., August 1975.
62
-------
PRIMARY STAjftlARD
FOR OZONE (0.08 p^m
14
DAY OF MONTH
Figure 8-7. Daily maximum and average ozone concentrations for Litchfield, Conn., July 1975.
to present a graph of August daily levels) . By comparing the Litchfield data (Fig-
ure 8-7) to the Middletown data (Figure 8-6a) , one can readily see that the Litchfield
site does not show the variation in daily maximum oxidant levels found at Middletown.
Furthermore, days on which peak ozone levels were measured at Litchfield frequent-
ly do not correspond to days on which peak ozone levels were measured at Middle-
town. Daily average ozone levels for Litchfield are also shown in Figure 8-7 to illus-
trate the fact that ozone levels tended to remain elevated during the nighttime hours,
resulting in daily average values being in violation of the standard on several
occasions.
Figures 8-8a and 8-8b present daily maximum and daily average ozone concentra-
tions for Scituate, RI, during July and August. Although the values are much lower
than those measured in Middletown, CN, the same general patterns in the day-to-day
fluctuations of ozone levels were observed. These same patterns of day-to-day fluc-
tuations in ozone levels for July and August were also observed at Framingham, MA
(Figures 8-9a and 8-9b) .
Although the daily maximum oxidant levels recorded at Framingham in July were
representative of Massachusetts in general, in August a very different situation
emerged; oxidant levels in Massachusetts varied along a north-south axis, with the
highest levels being found in southeastern Massachusetts. In Danvers, which is lo-
cated northeast of Boston, daily maximum ozone levels in July (Figure 8-10a) are
comparable to those in Framingham (Figure 8~9a) , but in August, ozone levels at
Danvers (Figure 8-10b) were generally lower than those measured in Framingham.
On the other hand, daily maximum ozone levels measured in August at Fairhaven, MA
(Figure 8-11), which is located in southeastern Massachusetts on the coast of Buz-
zard's Bay, were generally much higher than those measured in Framingham (Fig-
ure 8~9b) . (Insufficient data were available to graph the daily maximum ozone lev-
els for July at Fairhaven.) In addition, the daily maximum ozone values measured in
August at Fairhaven were very similar to those measured at Groton, CN (Figure 8-12) ,
which is located approximately 60 miles west-southwest of Fairhaven. Fairhaven and
Groton were also the sites with the most frequent violations in their respective states
63
-------
0.20
P^IMARYJTANDARD
FOR OZONE (0.08 ppm)
14
DAY OF MONTH
Figure 8-8a. Daily maximum and average ozone concentrations for Scituate, R.I., July 1975.
0.20
0.15 —
0.10 —
O.OS
14
DAY OF MONTH
Figure 8-8b. Daily maximum and average ozone concentrations for Scituate, R.I., August 1975.
in August (Tables 8-2 and 8-3), and the highest ozone level for August in Massachu-
setts was recorded at Fairhaven (Table 8-3) .
These observations are believed to be significant with respect to the different
meteorological conditions experienced in New England in July and August. Specifi-
cally, from preliminary review of meteorological data, it appears that northwest
wind flow was experienced more frequently in August and south to southwest wind
flow more frequently in July. The similarity of the Fairhaven and Groton data in
August would certainly be consistent with northwesterly wind trajectories. This
effect of meteorological conditions on ozone levels will be more thoroughly studied.
64
-------
0.20
0.15
0.10
0.05
0.0
A
(^PRIMARY^STANDARD
FOROZO*NE.!o.08ppni)
14
DAY OF MONTH
21
28
Figure 8-9a. Daily maximum ozone concentration for Framingham, Mass., July 1975.
0.20
0.15
0.10
0.05
0.0
MARYJTANDARD
OZONE Io.08ppm)
21
28
7 14
DAY OF MONTH
Figure 8-9b. Daily maximum ozone concentration for Framingham, Mass., August 1975.
31
Finally, hourly ozone data are presented for the air pollution episode of July 23-
24, 1975. This period was selected because it was the major episode during the
summer study (i.e., the highest measured ozone levels) . In addition, the surface
wind flow was from the southwest, a situation in which one would expect to find max-
imum transport of pollutants into southern New England.
Hourly ozone levels for various locations in Connecticut are presented in Figure
8-13. As can be seen, the daily maximum ozone concentrations occurred later in the
65
-------
0.20
0.15
0.10
O.OS
0.0
0.20
0.15
0.10
0.05
0.0
_PRIMAR_Y_STANDARD
~FOR OZONE 15.08 ppmT
14
DAY OF MONTH
21
28
31
Figure 8-10a. Daily maximum ozone concentration for Danvers, Mass., July 1975.
PRIMARYJJTANDAR 0
FOR OZONE (0.08 ppml
14
DAY OF MONTH
21
28
31
Figure 8-10b. Daily ozone concentration for Danvers, Mass., August 1975.
afternoon at monitoring sites along a northeasterly trajectory. Specifically, the
daily maximums on July 23rd, occurred at 1200 in Greenwich, at 1500 in New Haven,
and 1600 in Eastford.
This trend of later daily maximum ozone levels occurring along a northeasterly
trajectory continued in Rhode Island and Massachusetts. As presented in Figure 8-14,
on July 23 the daily maximum ozone levels in Rhode Island occurred at 1700 in
Scituate and 1800 in Providence. In Massachusetts (Figure 8-15), the daily maximum
ozone levels on July 23 occurred in the evening: Framingham at 1800, Danvers at
66
-------
PjMMARYJTANDARO
FOR~OZONE (0.08 ppni)
14
DAY OF MONTH
Figure 8-11. Daily maximum and average ozone concentrations for Fairhaven, Mass., August
1975.
0.20
0.15
0.10
0.05
0.0
PJJIMARY_STANpAj__
FOR"blONE«i.08ppm7
14
DAY OF MONTH
21
28
Figure 8-12. Daily maximum ozone concentration for Groton, Conn., August 1975.
2000, and Fairhaven (east of Rhode Island) at 2100. Furthermore, it is interesting to
note that the July 24 daily maximum ozone levels at Danvers and Framingham occurred
at 0800 and 0900, respectively.
Although no definite conclusions can be drawn from these data, transport of oxi-
dants and oxidant precursors is strongly indicated. Also, during this episode it ap-
pears that transport may have occurred up the Connecticut River Valley on July 24,
1975. Hourly ozone values on July 24 measured in Connecticut and Massachusetts
67
-------
0.30
0.25
0.20
0.10
0.05
HOUR OF DAY
Figure 8-13. Hourly ozone concentrations at three Connecticut sites, July 23-24, 1975.
0.15
0.10 —
O.OS —
0.0
1 M I M i II M 11 n 111111 n IN i II ru
PRIMARY STANDARD
FOROZOMEflMMffl)
n
24
16
20
12
16
20
23
HOUR OF DAY
Figure 8-14. Hourly ozone concentration at the two Rhode Island sites,
July 23-24, 1975.
within the Connecticut River Valley are presented in Figure 8-16. Daily maximum
ozone values were measured later in the day at the more northerly sites up the Con-
necticut River Valley: Middletown at 1100, Hartford at 1200, Enfield at 1300, Am-
herst at 1400. Whether this may be transport of ozone generated within the valley
itself or channeling of ozone from the larger air mass mixed with locally generated
pollution remains to be determined. This is another issue that will be studied in the
evaluation of the summer data that will be conducted during the next several months.
68
-------
4-1 I I I I I II II II I II 1 I I 1 I I II
HOUR OF DAY
Figure 8-15. Hourly ozone concentration at three Massachusetts sites,
July 23-24, 1975.
A lXi\i I i i i i i I -
24 1 2 3
IB 11 12 13 14 IS 1C 17 II II 20 21 22 23
HOUR OF DAY
Figure 8-16. Hourly ozone concentrations at four New England sampling sites.
69
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9. AERIAL INVESTIGATION OF PHOTOCHEMICAL
OXIDANTS OVER THE NORTHEAST
George T . Wolff and Paul J. Lioy
Interstate Sanitation Commission
New York, NY
George D. Wight
Connecticut Department of Environmental Protection
Ralph E. Pasceri
New Jersey Department of Environmental Protection
INTRODUCTION
For the past 3 years the Interstate Sanitation Commission has been coordinating a
study to investigate the phenomenon of elevated ozone levels in the tristate (New
York, New Jersey, Connecticut) area. Other participants in the study were the states
of New York, New Jersey, and Connecticut, the city of New York, and the U.S. En-
vironmental Protection Agency (EPA) , Region II, Surveillance and Analysis Group.
The study has included intensive surface monitoring at urban and rural sites, verti-
cal profile sampling, hydrocarbon analysis, and aerial surveillance. During the
period of August 10-22, 1975, the Commission, on behalf of and in cooperation with
the states of New Jersey, Connecticut, and New York, was funded by EPA to conduct
additional aerial ozone sampling. In addition to approximately 60 hours of flight time
funded by EPA, some flight time was funded by the New Jersey Department of Environ-
mental Protection. This paper describes some of the results of these flights.
The area included in the sampling program was within the Washington, DC, to Bos-
ton, MA, corridor and extended from northeastern Maryland to southern Connecticut.
This included sections of EPA Regions I, II, and III. The purpose of these flights was
to provide data in support of EPA's Northeast Oxidant Transport Study, conducted in
Region I. Since the most significant wind direction for the production and transport of
ozone in the northeastern part of the United States is from the southwest, it was im-
portant that the Region I study include similar data recorded in the regions to the south-
west (upwind) of Region I. Consequently, all of the flights and flight patterns were
coordinated with the meteorologist in charge of the EPA Region I study.
PROCEDURES
All of the aerial sampling was conducted using a Cessna 172 single engine air-
craft . Sampling lines were extended out over the wing from the cabin air intake port.
The location of the sampling line was to assure that there was no contamination from
the aircraft exhaust.
Ozone measurements were obtained using an AID portable chemiluminescent ozone
unit, while a Gardner Association condensation nuclei counter was used to measure
condensation nuclei. Hydrocarbon samples were obtained by pulling the sample into
a syringe, which was subsequently evacuated into a Tedlar bag. This procedure was
repeated until there was a sufficient sample in the bag. The bags were then analyzed
at either the Interstate Sanitation Commission's laboratory in New York City or the
70
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New Jersey Department of Environmental Protection's laboratory in Trenton, NJ.
Temperature measurements were obtained from the aircraft's thermometer, and wind
speed and direction were obtained either from Philadelphia or from the JFK Airport
prior to takeoff.
On most days, four flights were conducted: two in the morning and two in the
afternoon. Flights originated from Stratford, CN, and Trenton, NJ. The flights
from Stratford were manned by personnel from Connecticut Department of Environ-
mental Protection and the Interstate Sanitation Commission, while the flights that
originated from Trenton were manned by personnel from the New Jersey Department
of Environmental Protection and the Interstate Sanitation Commission. Flights were
conducted on August 10,11 (northern route only) , 15,19,20, and 21.
QUALITY ASSURANCE
In the spring of 1975, the Commission initiated a regional quality assurance pro-
gram for ozone calibrations. The Commission's ozone generator was calibrated with
the neutral buffered potasium iodide (KI) method and a Dasibi ultraviolet photometer
at the National Bureau of Standards (NBS) . The KI calibration was used as the ref-
erence method for this study. After the initial NBS calibration, the generator was
used to check the calibration of the generators maintained by New Jersey, New York,
and Connecticut, and EPA Regions I and II. All calibrations were within 7 percent of
the NBS calibrated concentrations. Subsequently, the Commission's generator was
returned to NBS twice during the summer for recalibration, with followup checks
made on the states' generators. This ensured a continuation of the uniform calibra-
tion across the region during the summer.
RESULTS AND DISCUSSION
The first point we wish to emphasize relates to the levels of ozone contained in
the air mass entering the New Jersey-New York-Connecticut area. We have previous-
ly stated that the air transported into the area frequently contains ozone levels ex-
ceeding the National Ambient Air Quality Standard. ^ On several of the days during
which flights were conducted, the data indicated that the air mass entering the region
exceeded 80 ppb prior to traveling over either major urban area (Philadelphia-cam-
den-Wilmington or New York City-northeast New Jersey) in the region.
With northwest winds prevailing on August 10 and 20 (Figures 9-1 and 9-2) , the
air entering the Philadelphia-Camden-Wilmington complex from the northwest con-
tained ozone levels in excess of 80 ppb. On the morning of August 10, the average
upwind concentration was 120 ppb, while on August 21 (Figure 9~3), the air enter-
ing the same area from the south-southwest contained an average of 136 ppb in the
afternoon. On northwest winds, Figure 9-4 shows levels exceeding the Air Quality
Standard upwind of the northeastern New Jersey-New York City metropolitan area
on August 10.
The remaining parts of this paper will focus on two areas: the urban plume and
large scale advection.
Investigation of Urban Plumes
The high frequency of northwest winds during the study period provided excel-
lent conditions to investigate the previously studiedl"^ urban plumes from the Phila-
delphia-Wilmington-Camden complex. The complex extends for approximately 30
71
-------
0930-1235 EOT
DIRECTION OF FLIGHT
».
OZONE VALUES IN ppb
MEASUREMENTS MADE «1000 ft
ABOVE GROUND
0930
EOT
110
TRENTON
PENNSYLVANIA
jjf BCAMDEN
MARYLAND
Figure 9-1. Ozone results for southern flight during morning hours of August 10, 1975.
72
-------
1606 EOT
1419-1710 EOT
DIRECTION OF FLIGHT
».
OZONE VALUES IN ppb
MEASUREMENTS MADE «1000 ft
ABOVE GROUND
1419 EOT
38
TRENTON
PENNSYLVANIA
ELKTON
MARYLAND |
1
Figure 9-2. Ozone results for southern flight during the afternoon hours of August 20, 1975.
73
-------
1405 -1700 EOT
DIRECTION OF FLIGHT
».
OZONE VALUES IN ppb
MEASUREMENTS MADE *<1000 ft
ABOVE GROUND
PENNSYLVANIA
147
• OXFORD
1547
EOT '119
ELKTONB
1632 EOT
TRENTON
142
1401
MARYLAND \
Figure 9-3. Ozone results for southern flight during the afternoon hours of August~21, 1975.
74
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CONNECTICUT
BRIDGEPORT
NEW
JERSEY
DOVER
112
0920-1221 EOT
DIRECTION OF FLIGHT
OZONE VALUES IN ppb
I FREEHOLD
Figure 9-4. Ozone results for northern flight during morning hours of August 10, 1975.
miles on a southwest to northeast line. Consequently, a northwest wind is roughly
perpendicular to the source region, and the downwind area has a very low density
of manmade sources.
Evidence of an urban plume from this complex was found on August 10 (Figures
9-2 and 9-5) and August 19 (Figure 9-6) . During three of these flights (Figures 9-1,
9~5, and 9~6), there appeared to be a plume centerline characterized by an ozone
gradient on both sides perpendicular to the centerline. Table 9-1 presents the av-
erage upwind concentration and the maximum observed downwind concentration.
For the Philadelphia-Wilmington-Camden complex, the average difference between
the average upwind and maximum downwind concentration was 36 ppb, with a range
of 16 to 55 ppb. These values are consistent with the difference previously observed.
The origin of this urban plume is thought to be a result of a cumulative effect of hy-
drocarbon and nitrogen oxide emissions in the Philadelphia-Camden-Wilmington com-
plex. Assuming a relatively constant wind direction on the 10th (310° in the morning,
260° in the afternoon), the centerline or downwind ozone maximum can be traced back
to south of Philadelphia, just north of Chester, PA. It is suggested that this be inves-
tigated further because of the number of oil refineries in this area.
75
-------
1410 -1635 EOT
DIRECTION OF FLIGHT
*~
OZONE VALUES IN ppb
MEASUREMENTS MADE «1000 ft
ABOVE GROUND
PENNSYLVANIA
148
ELKTONfe
NEMME^HSEY 1442 EOT
' ^ 169
1S8
(OXFORD 153
MARYLAND
f r
Figure 9-5. Ozone results for southern flight during afternoon hours of August 10, 1975.
76
-------
1442-1800 EOT
DIRECTION OF FLIGHT
»•
OZONE VALUES IN ppb
MEASUREMENTS MADE * 1000 ft
ABOVE GROUND
1442 EOT
PENNSYLVANIA
ELKTONB
MARYLAND
Figure 9-6. Ozone results for southern flight during afternoon hours of August 19, 1975.
77
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Table 9-1. OBSERVED UPWIND AVERAGE AND DOWNWIND MAXIMUM OZONE CONCENTRATIONS
Date
8/10
8/10
8/15
8/19
8/20
8/20
8/20
8/20
8/20
Time
a.m.
p.m.
p.m.
p.m.
p.m.
p.m.
p.m.
p.m.
p.m.
Urban area
Phil-Camden
Phil-Camden
NYC
Phil-Camden
Phil-Camden
Refinery
Bridgeport
New Haven
Connecticut
Upwind
average
concentration, ppb
113
139
50
78
85
95
69
79
80
Downwind
maximum
concentration, ppb
153
194
128
112
102
183
92
142
95
A ppb
40
55
78
34
16
88
20
66
15
Wind
NW
WNW
NE
NW
NW
NW
NNW
NNW
NNW
Day
Sunday
Sunday
Friday
Tuesday
Wednesday
Wednesday
Wednesday
Wednesday
Wednesday
Downwind
distance, mites
27
27
14
50
22
10
29
23
18
As a result of the observation near Chester, the flight pattern followed on August
20 (Figure 9-2) was modified to include flying downwind of a refinery located in Del-
aware . It was selected because it was relatively isolated from other nearby hydrocar-
bon sources and required only a minor modification in the flight pattern. The plume
was tracked visibly for about 15 miles. Upwind of the refinery, the ozone concentra-
tion was 95 ppb. The downwind concentrations were: 153 ppb at 4 miles, 163 ppb
at 10 miles, 183 ppb at 15 miles, and 122 ppb at 25 miles. Between 35 and 40 miles
downwind, the ozone concentration was again around 95 ppb.
In the northern sectors of the study, the northeast New Jersey and the New York
City area urban plume, which was previously observed, 1»4,5 was also investigated.
During August 15 (Figure 9-7) , the winds over the area were from the northeast.
Ozone concentrations measured at all locations that were not downwind of the New
York City-northeast New Jersey area averaged about 60 ppb (except for a few iso-
lated readings near New Haven) . Downwind in the vicinity of New Brunswick, NJ,
the ozone reached 97 ppb, with a well-defined gradient perpendicular to the wind
direction. Three hours later, the ozone over New Brunswick was 117 ppb, while a
maximum concentration of 123 ppb was observed 15 miles to the southwest near
Princeton. At the time, upwind of New York City over Bridgeport, CN, the observed
ozone values were only about 50 ppb.
As previously mentioned, because of the presence of northwest winds, a special
flight was conducted in the northern part of the study region on August 20 to inves-
tigate the transport of ozone from Connecticut to Long Island (Figure 9-8) . Several
observations were made on this flight. First, it appears that there is a Connecticut
plume. This is manifested by the ozone values over the north shore of Long Island
being higher (by an average of 17 ppb) than over the southern shore of Connecticut.
Since precursor emissions over the Sound should be negligible, it is reasonable to
attribute this increase to emissions in Connecticut. The ozone value over New Haven
was 79 ppb. Directly downwind on the north shore of Long Island, the ozone reached
78
-------
__ _ „ 13051 EOT
PENNSYLVANIA
DIRECTION OF FLIGHT
ALL OZONE VALUES IN ppb
ALL MEASUREMENTS AT ABOUT 1000 ft
ABOVE GROUND
Figure 9-7. Ozone results for northern flight during afternoon hours of August 15, 1975.
152 ppb. This supports the concept of ozone generation in transit from Connecticut
into Long Island (also See Figure 9~9a) .
The difference between the upwind and the downwind ozone concentrations with-
in the urban plume are evidence of ozone synthesis from urban sources. 5 This can
also be supported by examining the vertical profiles. The ozone values at the 2000-
foot level will be used below as a point of reference. This level is generally within
the haze layer and above the level at which ground level NO sources cause a depres-
sion in the ozone values.
On August 10, the winds were out of the northwest in the morning and shifted to
the west-southwest in the afternoon. On westerly winds, Trenton and New Bruns-
wick, NJ, would be free from influence by either of the two metropolitan areas. Fig-
ures 9~9B and 9~9C illustrate that the morning and afternoon ozone profiles for New
Brunswick and Trenton are very similar, with only a slight increase in ozone concen-
trations. The downwind sites, however, all show marked increases. At the 2000-
foot level, a 64 ppb increase was observed over Bridgeport (Figure 9-9D), 74 ppb
over Mamaroneck (Figure 9~9E) , and 41 ppb over Ancora, (Figure 9-9F) .
On August 19, northwest winds persisted throughout the day. The upwind sites
were Trenton, New Brunswick, Dover, and Bridgeport, while Bivalve was downwind
79
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STAMFORD
PORT JEFFERSON
1457 EOT
EASTPATCKOGUE
1253-1607 EDT
DIRECTION OF FLIGHT
ALL OZONE VALUES IN ppb
ALL MEASUREMENTS AT ^ 1000 ft
ABOVE GROUND
Figure 9-8. Ozone results for northern flight during afternoon hours of August 20, 1975.
of the Philadelphia-Wilmington complex, Vertical profiles completed at New Bruns-
wick and Dover (Figures 9~9G and 9~9H) show little evidence of ozone synthesis or
transport. The larger upwind urban areas, Trenton and Bridgeport, show increases
of 28 and 35 ppb, respectively. It seems reasonable that the increases are due pri-
marily to relatively local sources of precursors, since they are not downwind of any
major urban area. At 2000 feet, the ozone concentration at Bivalve (Figure 9~9K) in-
creased 38 ppb between 1024 and 1619 EDT. This could be attributed to transport
from the Philadelphia-Wilmington-Camden complex since the area between the urban
complex and the site is rural.
With northwest winds, similar observations were made over Trenton on August
20. At the 2000-foot level, the ozone increased 28 ppb. This supports the observa-
tions discussed in the preceeciing paragraph.
On August 15, verticals were made over Trenton, Bivalve, and Elkton before
sunrise and in the early afternoon. It is interesting to note that during all the verti-
cals before sunrise, ozone levels in excess of 80 ppb were observed except over
Trenton. In the afternoon, the ozone at the 2000-foot level at Trenton increased an
additional 45 ppb. Since the winds were from the northeast, it appears some of this
increase was due to transport from the New York metropolitan area. The Bivalve and
Elkton verticals show no evidence of ozone synthesis, but this may have been partial-
ly due to a thickening cloud cover that moved in from the south in the afternoon.
80
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I I
AUGUST 20
A-BRIDGEPORT1253
B^WTJ'EFFERSON
1480
c ~
C-EAST PATCH-
OGUE
1 I I
.AUGUST 20
NEW
BRUNSWICK
__ __
AUGUST 20
TRENTON
AUGUST 10
I BRIDGEPORT
\^
, AUGUST 10
MAMARONECK
v
+-d=r
AUGUST 19
DOVER
AUGUST 10
ANCORA
lH
AUGUST 19
_ NEW
BRUNSWICK
-t
AUGUST 19
TRENTON
AUGUST 19
BRIDGEPORT
i
I
fife
I 1 I
AUGUST 19
BIVALVE
SO 100 ISO 200 SO 100 150 200
50
100 ISO ,200
OZONE, ppb
Figures 9-9a through 9-9k. Vertical profiles for ozone at serveral sampling sites at various
sampling times for August 10, 19, and 20, 1975.
81
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Large-Scale Ozone Advection
Since the highest ozone values observed in the northeast generally occur on
southwest winds, it was important that this condition be investigated. Southwest
winds occurred during the afternoon of August 21.
On the afternoon of August 20, with light north-northwest winds prevailing, ozone
values were relatively low over the region with two exceptions: parts of Long Island
and New York City, and the extreme southern portion of the southern flight area (see
Figures 9-8 and 9-2) . On the morning of the 21st, these high concentrations continued
to persist over the extreme southern portion (Figure 9~10) but not over the New York
City area (Figure 9-11) . South of Philadelphia, the ozone concentrations ranged from
107 to 122 ppb, while north of Philadelphia extending into Connecticut, it ranged from
20 to 70 ppb. Winds overnight and into the morning were light and variable (<3 mph) .
Consequently, very little transport could occur. Between 1100 and 1200, the winds
shifted and a very strong south-southwest flow was established over the region from
the surface to 3000 feet. During the afternoon, the skies over the region were partly
cloudy (ranging from 30 to 60 percent cloud cover) and hazy sunshine persisted. As
a result, the meteorological conditions were conducive for ozone synthesis and trans-
port. The dramatic changes in the meteorological conditions that occurred during the
day are illustrated in Table 9-2.
As the wind shifted, it appeared that the air containing the high ozone over the
southern part of the region moved rapidly northeastward through the New York City
area around 1430 to 1500 EOT, (Figures 9-12 and 9~3) . Since the wind shift at Phila-
delphia occurred around 1100 EDT, the air south of Philadelphia would have to trav-
el about 80 miles in 3.5 to 4 hours (20 to 25 mph) . Table 9-2 indicates that conditions
were conducive for such rapid transport. Surface observations of ozone levels also
supported rapid transport. At Ancora, located in southern New Jersey, the ozone rose
rapidly between 1100 and 1200 EDT from 29 to 67 ppb and reached its maximum of 101
ppb between 1200 and 1300 EDT. Further north in New Jersey, Bayonne reached 73
ppb between 1300 and 1400 EDT and the ozone continued to rise until 1800 hours when
it reached 100 ppb. Traveling further northeastward, Stamford, CN, reached 60 ppb
at 1400 EDT and 90 ppb by 1500 EDT. In New Haven, CN, the ozone levels did not
reach 70 ppb until 1700 EDT. All these sites demonstrated rapid increases in ozone,
but most significant was the time at which it occurred.
The high levels of ozone over Connecticut (about 180 ppb) cannot be attributed
solely to transport from the southern New Jersey-Delaware area because the maximum
concentrations observed in the southern area on the afternoon of the 20th and the morn-
ing of the 21st were on the order of 120 ppb. This is excluding the very localized high-
er values observed downwind of the refinery plume. It is reasonable to assume that
at least 60 ppb of ozone was synthesized in route from extreme southern New Jersey
to Connecticut.
SUMMARY
1. With one exception, i.e., downwind in the urban plume, ozone appeared to be
uniformly distributed over the study area, which included: extreme northeastern
Maryland, northern Delaware, southeastern Pennsylvania, New Jersey, the New York
City metropolitan area, and southeastern Connecticut, on most of the days examined.
2. There was evidence of an urban plume emanating from Philadelphia-Camden-
Wilmington metropolitan area, the northeastern New Jersey-New York City-southeastern
Connecticut metropolitan area, and New Haven, CN.
82
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0928-1201 EOT
DIRECTION OF FLIGHT
»,
OZONE VALUES IN ppb
MEASUREMENTS MADE «1000 ft
ABOVE GROUND
PENNSYLVANIA
ELKTON»
MARYLAND!
Figure 9-10. Ozone results for the southern flight during morning hours of August 21, 1975.
83
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CONNECTICUT
BRIDGEPORT
DOVER
51
0905 -1200 EOT
DIRECTION OF FLIGHT
»»
OZONE VALUES IN ppb
FREEHOLD
Figure 9-11. Ozone results for northern flight during morning hours of August 21, 1975.
Table 9-2. METEOROLOGICAL CONDITIONS,
1000 AND 2000 EOT, FORT TOTTEN,
NEW YORK, AUGUST 21, 1975
Altitude, ft
SFC
2000
3000
4000
5000
6000
' i
Wind speed (mph) and direction
1000 EOT
NE60°@8
NW 290° @ 7
NNW300°@18
2000 EOT
SSW @26
@39
SW @ 48
@47
WSW @ 50
84
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CONNECTICUT 1708 EOT
BRIDGEPORT
NEW
JERSEY
DOVER
137
1345 -1709 EOT
DIRECTION OF FLIGHT
_••.
OZONE VALUES IN ppb
!FREEHOLD
Figure 9-12. Ozone results for northern flight during afternoon hours of August 21, 1975.
3. The maximum increases in the ozone observed within Philadelphia-Camden-
Wilmington and northeastern New Jersey-New York City-southeastern Connecticut
urban plumes were 55 ppb and 78 ppb, respectively.
4. Large-scale advection of ozone was observed on August 21 from Delaware
to Connecticut, a distance of approximately 180 miles.
5. Ozone synthesis was observed as an air mass traveled from southern Connect-
icut over the Long Island Sound to Long Island. The net generation was on the order
of 15 to 20 ppb.
6. There is evidence of significant ozone generation downwind of oil refineries.
7. There is some evidence, which needs to be investigated further, that much of
the ozone observed in the Philadelphia-Camden-Wilmington urban plume may originate
just to the south of Philadelphia rather than in the center of the city. This area con-
tains several large refinery complexes.
8. The data support past conclusions that the air mass entering New Jersey and
in New Jersey-New York-Connecticut Air Quality Control Region from a westerly di-
rection frequently contains ozone concentrations exceeding the National Ambient Air
Quality Standard.
85
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9. The extremely high ozone levels previously recorded in Connecticut did not
occur during the study period. Consequently, it is recommended that additional
flights be conducted during the earlier part of the summer when such episodes are
more frequent.
ACKNOWLEDGEMENTS
The authors wish to express our gratitude to the following people for their sup-
port in this project: Vincent Krushak (New Jersey Department of Environmental Pro-
tection) and Thomas Peters and Michael Anderson (Connecticut Department of Environ-
mental Protection) for conducting many of the flights, and Richard Taylor (New York
State Department of Environmental Conservation) for his assistance in interpreting
the meteorological data.
We extend our appreciation also to Robert Witby (New York State Department of
Environmental Conservation) and William Ormand (New Jersey Department of Environ-
mental Protection) for their analyses of the hydrocarbon samples, and to Konrad
Wisniewski (Interstate Sanitation Commission) for conducting many of the experiments
and for coordinating the quality assurance program.
REFERENCES
1. Wolff, G.T., W.N. Stasiuk, P.E. Coffey, andR.E. Pasceri. Aerial Ozone Meas-
urements over New Jersey, New York, and Connecticut. Paper 75-58-6. Pre-
sented at the Annual Air Pollution Control Association Meeting, Boston, Massa-
chusetts, June 1975.
2. Cleveland, W.S. and B. Kleiner. The Transport of Photochemical Air Pollution
from the Camden-Philadelphia Urban Complex. Environ. Sci. Technol. 1975.
3. Rubino, R.A., L. Bruckman, and J. Magyar. Ozone Transport. Paper 75-07-1.
Presented at 1975 Air Pollution Control Association Meeting, Boston Massachusetts,
June 1975.
4. Wolff, G.T. Preliminary Investigation of Photochemical Oxidants in New Jersey-
New York-Connecticut A.Q.C.R. Interstate Sanitation Commission, New York,
N.Y. April 1974,
5. U.S. Environmental Protection Agency. Control of Photochemical Oxidants—
Technical Basis and Implications of Recent Findings. July 15, 1975.
86
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10. AIR QUALITY ABOVE THE MORNING SURFACE
INVERSION AND ITS EFFECT ON URBAN OZONE CONCENTRATION
Robert A. Whitby
New York State Department of Environmental Conservation
Albany, NY
INTRODUCTION
In 1973 and 1974, Drs. William Stasiuk and Peter Coffey discovered that New York
rural air monitoring stations exhibited violations of the National Ambient Air Quality
Standard for ozone as frequently as urban stations, although the urban stations had
higher maximum values during mid- to late-afternoon periods. Rural stations separat-
ed by distances of 300 miles showed remarkably similar patterns; ozone concentration
increased as high pressure systems entered the region and decreased as the systems
moved away. Urban levels snowed the typical diurnal variation, with maximums fol-
lowing the general rural pattern associated with high pressure cells. Rural levels
were found to have little diurnal variation. Transport of ozone and/or precursors
could not explain such events; thus, we considered a significant proportion of the
ozone observed to be a regional air mass characteristic. Since there were often wide-
spread ozone levels in excess of the standard, the air mass levels alone were consid-
ered to contribute significantly to the typical urban diurnal pattern through a mixing
and transport mechanism. To test this hypothesis and to provide greater understand-
ing of ozone variations, a study of air quality above the urban nocturnal inversion
was undertaken. The objectives of this study were:
1. Establishment of a high altitude urban monitoring site.
2. Measurement of ozone above and below the low level nocturnal inversion.
3. Measurement of nitrogen oxides and hydrocarbons associated with ozone
levels.
4. Measurement of regional ozone and vertical ozone profiles by instrumented
aircraft flights.
The high altitude urban site was located at the 82nd floor of World Trade Center II
(308 meters), while a ground level station was located at Roosevelt Island. The low
level nocturnal inversions were found to occur both above and below the World Trade
Center site level. Instrumented aircraft flights were made on 8 days in June, the 17th
through 24th. Other state agencies provided hourly ozone data for the mid-Atlantic
States region in order to plot regional ozone isopleth maps. Data from 95 individual
stations were utilized.
WORLD TRADE CENTER SITE
Ozone, NO, and NO2 were monitored continuously from June through September
1975 at the 82nd floor (308 meters) of the World Trade Center (WTC) , Tower II, in
New York City (Figure 10-1) . Sample was drawn by the instrument through a 1/4-
87
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inch O.D . Teflon sample line that ex-
tended horizontally from the building a
distance of 10 feet and was supported in
an aluminum conduit. A single instru-
ment, an Aero-chem Chemiluminescence
Analyzer, was used to monitor all three
species. Fire laws prohibited the use
of ethylene chemiluminescence monitors.
During August, an acoustic sounder
was employed at nearby Roosevelt Island
to measure low level nocturnal inversions.
03, NO, and NOX data for the period
August 8-12, typical of the study period,
are presented in Figure 10-2. Wind
directions for the period were generally
west to north-northwest as the region
was under the influence of a modified
summertime polar air mass that had de-
veloped over the southern Canadian
Rockies on August 4 and moved east-
southeastward across the United States
into the southeastern states by August
12. During August 6, 7, and 8, cloudi-
ness and rainy periods covered the sam-
ple area. This was a period of low ozone
throughout the mid-Atlantic region. By
the 9th, high pressure was established over the eastern third of the country. At
this time, the ozone increased markedly and remained elevated until the high moved
into the deep south. The high pressure system appeared to have greater effect on
the ozone levels than the morning inputs of NO. NO did exhibit scavenging effects
on ozone, but the NOX~O3 interrelationships are difficult to assess due to continuous
inputs, atmospheric mixing, and advection.
Figure 10-1. Sampling sites in the New York City
area.
WORLD TRADE CENTER. 308 M
PPB OZONE
PPB NO
PPB NOx
AUGUST a
FRIDAY
AUGUST 9
SATURDAY
AUGUST 10
SUNDAY
AUGUST II
AUGUST 12
Figure 10-2. Ozone and nitrogen oxides levels at
New York City site.
88
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OZONf <
OZONf•
WOULD THAOf CtNTIR, 301 M
ROOUVILT ItlANO,
WOUND LtVIL STATION
AUGUST 12
TUESDAY
Ozone was also monitored at
the Roosevelt Island ground level
'station 7.2 miles northeast of the
WTC (see Figure 10-1) . The data
presented in Figure 10-3 show three
well developed nocturnal inversions
o below the 308-meters level of the
I WTC site. During the inversion of
^-August 9-10, the 63 levels observed
-200 | at the WTC site were much higher
| than at the ground site. Addition-
Is ally, the highest 63 values occur
, S(near midnight, a result quite simi-
lar to previous observations at
ground level rural stations in New
York State. Somewhat the same re-
sults were observed for the inver-
sion condition of August 10-11.
Figure 10-3. Ozone and inversion data (measured
by acoustic sounder) at World Trade Center and
Roosevelt Island.
On August 8-9, the 03 levels
were low both above and below the
nocturnal inversion. As previous-
ly stated, the period of August 6-8 was one of low regional 03; thus, the air layer
obierved above would be expected to be low in ozone.
The data indicate that the air layer above the nocturnal inversion exhibits charac-
teristics associated with ozone levels observed at ground level rural stations in New
York State; it appears fairly representative of background ozone levels plus any accu-
mulation of ozone from photochemical processes during the day. When separated from
ozone scavengers by the nocturnal inversion, the upper air layer retains a relatively
high 03 content which, following the breakup of the inversion, will mix with ozone-
depleted air near the surface and contribute to the typically observed increase in ozone
through the day at surface sites.
INSTRUMENTED AIRCRAFT STUDIES
Instrumented helicopter flights over the New York-New Jersey area between Tren-
ton and New York City were made on 8 days in June, the 17th through 24th. A New
York State government helicopter was instrumented with an AID portable ozone moni-
tor calibrated by the Interstate Sanitation Commission (NBS calibration) and provided
with altitude correction data by the manufacturer. A 5-foot length of Teflon tubing
extended from the helicopter through the door seal. Ground and air tests with various
lengths of tubing indicated the system used was not affected by aircraft exhaust or
rotor wash.
The flight of June 23 was considered representative of a high ozone situation,
and flight data are presented in Figures 10-4 to 10-7. F'igure 10-4 is a map of the
NJ-NYC region with flight path, altitudes (feet), times (EDT), and ozone levels (ppb)
indicated. The meteorological conditions were those typically favoring high ozone
level development in this region: a high pressure system was located off the mid-
Atlantic coast; surface winds were southwest at 11 knots; 1000- to 2000-foot winds were
west-southwest at 24 knots; 3000- to 10,000-foot winds were west-northwest at 10 knots;
89
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MONDAY 6/23/78
MORNIN8 FLI0HT PATH
Figure 10-4: Flight pattern and ozone results
(in ppb) for morning flight of June 23, 1975.
OIOHC VDtTKAL raVK.II 1/tVTt AH
Figure 10-5. Vertical ozone profiles at three loca-
tions measured during morning flight of June 23,
1975 (Figure 10-4).
there were early morning low level inversions (data from Fort Totten) at surface to
200 meters and 419 to 910 meters. There was a subsidence inversion based at 1817
meters with a top of 2149 meters, which lowered to the 1500-meter level during the
afternoon.
During the morning flight (Figure 10-4), 03 levels increased with altitude from
7 ppb at the surface at Trenton to about 55 ppb at the 1000-foot level. A vertical to
«/i»/ra **
-<4KKCM*M
OZO*e M MMT1 W •LL.NM
_ Figure 10-7. Vertical ozone profiles at two loca- '
Figure 10-6. Flight pattern and ozone results (in tions measured during afternoon flight of June 23,
ppb) for afternoon flight of June 23, 1975. 1975.
90
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5000 feet was made at the WTC. Ozone levels remained at about 55 ppb on the third
leg at 1000 feet. Another vertical was performed_a^Asburj Park. Onjthe southerly
third leg at 1000 feet the ozone remained at the 55-ppb level, but was much higher
(75 to 97 ppb) at 3000 and 4000 feet. A third vertical was made at Hightstown.
The verticals showed reduced levels of ozone below the morning inversion heights
at all three locations (Figure 10-5) . Ozone was 70 to 100 ppb from 2000 to 4000 feet
and 100 to 110 ppb from 4000 to 5000 feet. The profiles were similar at WTC and
Hightstown, while levels below 1000 feet were slightly higher at Asbury Park, quite
probably reflecting a lower amount of ozone scavenging due to less local pollution.
Figure 10-6 presents the afternoon flight path for June 23. The flight path was
reversed in direction from that of the same morning and a 3-hour stop at LaGuardia
Airport was required. Vertical ozone profiles were obtained at Asbury Park and the
WTC. Winds during the flight remained from the southwest. Ozone levels on the
southern leg had increased from about 55 ppb during the morning to 90 to 133 ppb
at 1000 feet. Increasing levels of ozone were encountered approaching New York City
from the southwest. During the return flight in the late afternoon, values of approx-
imately 200 ppb were observed over central New Jersey.
Of particular interest are the afternoon profiles at Asbury Park and the WTC
shown in Figure 10-7. The former shows a nearly constant concentration of ozone
with altitude (105 to 115 ppb) . This concentration is virtually the same as the region-
wide ozone concentration at 4000 to 5000 feet during the morning flight. The lack of
large scale sources of scavengers in the Asbury Park area and a well developed sea
breeze result in a uniform mixing of ozone from aloft with low ozone destruction. This
is possibly the best approximation of the regional background ozone concentration.
This does not necessarily mean "natural" background ozone; the various sources of
this regional background level are a matter of debate and require further investigation,
Above 3000 feet, the WTC profile is in good agreement with the regional background
concentration (110 to 120 ppb), but is significantly higher (180 to 200 ppb) below
3300 feet. It should be noted that, except for Staten Island, the WTC was upwind of
New York City hydrocarbon and NOX sources and the air entering the New York City
area had a measured ozone concentration of 150 ppb. This indicates that precursors
to the southwest of New York City are being emitted and photochemically reacting to
produce 03, which subsequently is advected into New York City. Thus, New York
City can suffer from photochemical pollution not of its own making as well as generate
ozone precursors that may cause further ozone pollution downwind. The contribution
of sources upwind of New York City should be considered when assessing the impact
of New York City sources on receptors downwind.
OZONE ISOPLETH MAPS
Figures 10-8 to 10-11 map the surface ozone conditions for the day of the flight
over the mid-Atlantic states. The maps were Dlotted from data submitted by 95 moni-
toring stations (Figure 10-12 and Table 10-1) . Wind directions at the surface and a-
bove 5000 feet are indicated on the maps for the New York City area. The maps indi-
cate the very widespread nature of high ozone levels, indicating a regional problem.
Some very high centers develop and grow throughout the day; however, this effect
appears to be superimposed upon the regional phenomenon.
The isopleth maps and flight data for the entire study period indicate a general
increase near the surface during the morning over a wide region and a further in-
crease during the day, particularly downwind oFurban areas. A combination of local
91
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O-j generation and destruction,
mixing of ozone-rich air from a-
loft with ozone-depleted air at
the surface, and advection appear
to be producing the levels and pat-
terns of ozone observed at ground
level.
HYDROCARBON-OXIDANT STUDIES
Ambient hydrocarbons in the
C2~C£ range were measured by
gas chromatographic techniques
at the WTC (308-meter altitude)
and Interstate Sanitation Commis-
sion Laboratories (ISC) , fourth .
floor, W. 48th, Manhattan. Ap-
proximately 75 integrated 3-hour
samples were collected in 5-liter
Tedlar bags over the period June
20 through August 20. During
the period July 7-18, an intensive
sampling program was under-
taken on weekdays. Samples were
collected by an automated system at 0530 to 0830 hours and 1230 to 1530 hours at the
WTC and ISC sites. The early sample was not available on Mondays and three ISC
samples were missing for the period. Analysis was made by cryogenic trapping of
hydrocarbons from a 70-cm^ aliquot of the ambient sample. The concentrated sam- •
pie was injected to the GC column (2 feet x 1/16-inch. 07D. activated alummaJTwhicn
was temperature programmed from 20°C to 200°C. Figures 10-13 and 10-14 present
^representative calibration and ambient chromatograms.
Individual hydrocarbons were grouped as C^-C^ paraffins, C2~C6 olefins, and
acetylene and plotted for each site in Figure 10-15A. The data points represent 3-
hour integrated averages and the graph is, thus, not intended to present a continuous
Figure 10-8. Ozone isopiethsfor 1100-1200 time
period of June 23, 1975, constructed using data
from a network of 95 ground-based sampling
stations.
Figure 10-9. Ozone isopleths for the 1300-1400
time period of June 23, 1875, constructed using
data from a network of ground-based sampling
stations.
Figure 10-10. Ozone isopleths for the 1500-1600
time period of June 23, 1975, constructed using
data from a network of 95 ground-based sampling
stations.
92
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OZONE ISOPLETHS
e/28/78
S-6 RM.
Figure 10-11. Ozone isopleths for the 1700-1800
time period of June 23, 1975, constructed using
data from a network of 95 ground-based sampling
stations.
Figure 10-12. Geographic location'of the 95 ground-
based ozone sampling sites.
93
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Table 10-1. LISTING OF MONITORS SUPPLYING DATA
USED IN MAKING OZONE ISOPLETHS - BY STATE
New York State Monitors
1. Niagara Falls
2. Amherst
3. Buffalo No. 1
4. Rochester
5. Syracuse No. 1
6. Syracuse downtown
7. Utica
8. Glens Falls
9. Schenectady
10. Rensselaer
11. Elmira
12. Kingston
13. Mamaroneck
14. Roosevelt Island
15. Eisenhower Park
16. Babylon
Massachusetts Monitors
17. Pittsfield
18. Greenfield
19. Fitchburg
20. Lowell
21.'" Amherst
22. Worcester
23. Springfield
24. Framingham
25. Waltham \
26. Medford
27. Salem
28. Cambridge
29. Boston
30. Quincy
31. Fall River
,
Connecticut Monitors
32. Greenwich
33. Stamford
34. Bridgeport
35. New Haven
36. Groton
37. Hamden
38. Middletown
39. Danbury
40. Morris Dam
41. Torrington
42. Windsor
43. Enfield
44. Eastford
New Jersey Monitors
45. High Point
46. Chester
47. Somerville
48. Bayonne
49. Sandy Hook
50. Asbury Park
51. McGuire Air Force Base
52. Camden
53. Ancora
54. Bivalve
Pennsylvania Monitors
55. Erie
56. New Castle
57. Beaver Falls
58. Baden
59. Charleroi
60. Johnstown ~~
61. Harrisburg
62. York
63. Lancaster
64. Reading
65. Chester
66. Norristown
67. Bristol
68. Bethlehem
69. Allentown
70. Wilks-Barre
71. Scranton
Delaware Monitors
72. Wilmington
Maryland Monitors
73. Baltimore city, Calvert and 22nd
74. Baltimore city. Green and Lombard
75. Bethesda
76. Silver Spring
77. Cheverly
78. Suitland
Virginia Monitors
79. Fairfax
80. McLean
81 . Seven Corners
82. Shirlington Road
83. Alexandria
84. Engleside
85. Fredericksburg
86. Richmond City, Spencer Road
87. Richmond City, State Fair Grounds
88. Richmond City, McGuire VA Hospital
89. Richmond City, 501 North 9th
90. Hampton
91. Norfolk
92. Nansemond
93. Salem
94. Marion
West Virginia Monitors
95. Charleston
Street
94
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J
Figure 10-13. Composite calibration chromatogram.
TIME turn}
Figure 10-14. Some results of detailed hydrocarborf
analyses for typical ambient air sample.
95
-------
Hydrocorbon ObMfvooons, AM ond PM t
Cj - C6 Paroffios C; - C« Olit.M Ae*tytan«
0—0 ISC t. & ISC O—-DISC
r7! i • jy"1 ~s t ' )T"
WOULD TRADE CENTER
3 Hour Average Ot)iervat«ni
WTC
ROOSEVELT ISLAND
a 9 ^ 10
Figure 10-15. Hydrocarbon, nitrogen oxides, and
ozone observations during study periods of July
7-11 and 14-18 in New York City.
record. Oxides of nitrogen and ozone were monitored continuously and plotted as
3-hour average values in Figures 10-15B and 10-15C, respectively.
Certain hydrocarbon resolutions in the area of the butenes and pentanes were
difficult with the analytical procedure used and it is quite possible that our identifi-
cation of cis-2-butene and 2-methylpropene includes a significant amount of isopen-
tane. Mr. William Lonneman of EPA reports that one typically finds the isopentane-
pentane pair upon chromatographic analyses of urban air. This would somewhat af-
fect the olefin and paraffin values plotted in Figure 10-15A. Nonetheless, significant
levels of hydrocarbons were found at the WTC to produce high ozone levels through
photochemical reactions with oxides of nitrogen.
Our data indicate that a somewhat different hydrocarbon composition exists at the
WTC and ISC locations, indicating different degrees of source influences or reactive
losses during advection. There were days during the study period, however, when
several compounds had very similar ratios at both sites, indicating simple dilution.
Winds during the first week were variable from the southeast to northeast; during the
second week, winds were consistantly from the south to southwest. There were heavy
rains from July 14 through July 16.
High ozone levels were observed during both weeks, but very low ozone was ob-
served during the period of heavy rain. During the first week, NO and NO2 levels
of 20 to 60 ppb were observed during the morning with approximately 400 to 800
Wg/m3 hydrocarbon levels at WTC. On July 17 and 18, both hydrocarbon and NOX
levels were reduced, yet significant ozone buildup occurred. Although there was a
reduction of absolute values, a comparison of HC/NOX ratios on the mornings of July
10 and 18 shows a higher ratio on the 18th. Although it must be cautioned that the
96
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air parcels observed in the morning and afternoon may have different chemical com-
position histories, which invalidates comparison of morning hydrocarbon-NOx levels
with afternoon 03 levels, it is plausible that significant photochemical ozone produc-
tion has been observed.
There is evidence that the WTC was above a low level inversion on the mornings
of July 9^and 10, conditions similar to those observed on June 23 when the vertical
03 profile in Figure 10-5 was made. On July 18 the morning sounding at Fort Totten,
taken at 0700 hours, showed a 1.5°C inversion between 300 and 410 meters; there-
fore, the WTC was about level with the base of this early morning inversion. Thus,
it is also possible that a high level (approximately 100 to 150 ppb) of ozone could
exist in air layers aloft (2000 to 5000 feet) on these dates and that an upper air layer,
upon mixing with lower levels following inversion dissipation, could contribute sig-
nificantly to the afternoon 63 peak.
It is likely that the processes of photochemical production of ozone, advection of
ozone, mixing of ozone rich upper air with ozone depleted lower air below an inver-
sion, and ozone scavenging by NO and surface reactions all play significant roles in
generating the magnitude and patterns of ozone concentrations observed at ground
level stations. The importance of each of these processes in any instance may well
depend upon the site locations, pollutant inputs, and meteorological conditions at
the time.
97
-------
11. OZONE FIELD AUDITS FOR
1975 NORTHEAST OXIDANT TRANSPORT STUDY
Thomas M. Spittler
U.S. Environmental Protection Agency, Region I
Boston, MA
In order to assist the Air Branch in its evaluation of ozone data collected in New
England during the 1975 ozone season, and in order to provide a common reference
point for intercalibration of ozone sensors for all participants in the Northeast Oxi-
dant Transport Study, the Technical Support Branch, Surveillance and Analysis
Division, EPA Region I, undertook an extensive audit program covering the period
May 20 to November 14, 1975. During this time period, 74 separate audits were per-
formed on field ozone sensors.
Active participants in the Transport Study included the states of Connecticut,
Massachusetts, Rhode Island, and New Hampshire; portable trailers were set up and
operated by groups from the Research Triangle Park and Las Vegas Environmental
Protection Agency Laboratories as well as by contractors from Battelle Institute, Co-
lumbus, OH, and Washington State University. The latter groups also provided
planes equipped with ozone monitors for overflight data. Additional audits were made
late in the season on ozone sites in Burlington, VT, and Portland, ME. Finally, inter-
laboratory calibrations were performed on August 14 with the Interstate Sanitation
Commission and the State of Connecticut at Greenwich, CN, and on a National Bureau
of Standards ozone generator shipped to the Region I laboratory in November. This
calibrator was then loaned to the states of Massachusetts, Connecticut, and Rhode
Island as well as to a private research laboratory before being returned to NBS for
post calibration. Table 11-1 shows the various sites by name, collaborator, and
geographic location.
AUDIT TECHNIQUE
Because of the need to recheck calibration of our ozone generator after each audit
trip, field audits were all made as 1-day trips. Prior to a field audit, the ozone gen-
erator (AID Model 565) was calibrated in our laboratory using the neutral buffered
potassium iodide (KI) technique (F.R. 36. No. 228, 22393-22395). During the period
May 20 to June 18, 1975, only a few KI calibrations were performed. An in^novfseTien-
dix 03 monitor was used to record these calibrations. Before and after field audits,
the ozone generator was checked against this Bendix monitor. The KI technique was
subsequently reevaluated at EPA-RTP, and several modifications were proposed in a
draft memorandum dated April 14, 1975. The proposed modification to Section 5.10.1
substitutes a midget impinger for the "Mae West" bubbler pictured in the original
published method. The accompanying statement is "MSPEB and others have found that
midget impingers recover up to 15 percent more 12 than the Mae West type bubbler."
At the EPA Region I laboratory, the Mae West bubbler had been in use prior to this
modification. Indeed it continues in use to this day. It has been our experience that
the Mae West bubbler does indeed cause lower I? recovery (about 15 percent) when
the sampling flow is reduced from 800 to 300 cm^/min in the bubbler, but at a flow
rate of 800 cm^/min, we find no difference between the Mae West and midget impinger
bubblers.
98
-------
Table 11-1. LOCATION
OF OZONE COLLABORATOR SITES
State sampling sites
State
Salem
Wellington
Quincy
Framingham
Worcester
Amherst
Eastford
Enfield
Windsor
Middleton
Hamden
New Haven
Manchester
Nashua
Providence
Scituate Reservoir
Massachusetts
Connecticut
New Hampshire
Rhode Island
On or about June 18, 1975, an in-
advertent change was made in the
Region I laboratory procedure for cal-
ibrating ozone generators. A new team
assumed responsibility for ozone cali-
bration and arbitrarily chose a flow of
300 to 400 cm3/min for collecting ozone
in the Mae West bubblers. Previous
calibrations (in 1974 and early 1975)
were made using a flow of 800 cm^/min.
Both flows were well within the 200
to 1000 cm^/min range recommended.
Prior to this change, 16 field audits
were performed using the high-flow
calibration data. Subsequent to this
change in flow, an active program of
field audits was conducted based on
^ the low-flow calibration.
On or about September 6, 1975, a
summary of the summer audits was be-
gun. At this time, a pronounced shift
in audit data was noted. Values at all
sites audited after June 18 were found
to have shifted upward, and an expla-
nation was sought. Detailed examina-
tion of laboratory record books finally
pointed to the change in sampling flow
from 800 to 300 cm^/min as one possi-
ble cause. A careful investigation of
this flow problem did indeed reveal
that a consistent loss of about 15 per-
cent was experienced when the lower
flow was used. All field audits between
June 19 and September 6 had been
based on direct calibration of the ozone
generator by the KI method. A tabula-
tion of these data showed very consist-
ent results (Table 11-2) . Examination
of recorder charts from an in-house Bendix ozone monitor used to verify all calibrator
recordings before and after audits performed during the period April 20 to June 18
also showed good consistency (Table 11-3) . The two sets of data are plotted in Figure
11-1. As may be readily seen, there is a consistent difference of about 16 percent be-
tween the two curves over the useful concentration range (0.1 to 0.3 ppm) . This dis-
crepancy agreed well with the 14 percent difference found during our study of the
flow problem and the 15 percent difference discussed in the April 14 document from
Research Triangle Park. Table 11-4 shows some of the data developed during this
study. The large discrepancy at a sleeve setting of 200 indicates the problem inher-
ent in attempting KI calibration of an 03 generator at levels below 0.1 ppm 03. It
should be noted that the data in Table 11-4 were developed on a different generator
(II) than the data used in Figure 11-1 (generator I) . Ozone output versus sleeve
setting is not directly comparable between generators owing to difference in lamp
temperature, lamp output, etc.
Special sampling sites
Location
Battelle
Washington State University
EPA-RTP
EPA-LV
State of Connecticut Laboratories
EPA, Region I
Simsbury, CN
Groton, CN
Quincy, MA
Weymouth, MA
Greenwich, CN
Needham, MA
99
-------
Table 11-2. NEUTRAL BUFFERED Kl CALIBRATION
DATA, JUNE 20 TO SEPTEMBER 4,1975,
SAMPLE FLOW 300 TO 400 cm3/min
Date
6/20
6/27
6/30
7/9
7/15
7/18
7/21
7/29
8/6
8/14
8/27
8/28
9/14
Average
03, ppm, at
sleeve
setting
300
0.08
0.10
0.09
0.08
0.09
0.08
0.08
0.08
0.097
-
0.097
0.095
0.095
0.088
03, ppm, at
sleeve
setting
500
0.15
0.17
0.16
0.15
0.17
0.16
0.15
0.15
0.16
0.16
0.156
0.15
0.145
0.156
03, ppm, at
sleeve
setting
700
0.21
0.22
0.22
0.21
0.23
0.22
0.21
0.21
0.21
0.21
0.217
0.205
0.20
0.213
Table 11-3. BENDIX INSTRUMENT
RESPONSE TO TWO SETTINGS OF AID
GENERATOR DURING PERIOD MAY 20
TO JUNE 17.1975
(Kl calibration at flow of 800 cm3/min)
Date
5/20
5/21
5/27
5/28
6/4
6/10
6/13
6/16
6/17
Average
800 sleeve
setting
0.30
0.30
0.295
0.295
0.29
0.30
0.295
0.295
•„ 0.29
0.32
0.297
400 sleeve
setting
0.13
0.145
0.15
0.155
-
0.15
0.15
0.14
-
0.16
0.148
• Kl CAUIRATION AT JM4M tm'/mm
• ItHOIX «OHITOR DMA USED Oh
Kl CALIMATIIM AIM «3/.,,
Table 11-4. COMPARISON OF Kl CALIBRATION
USING FLOWS OF 300 AND 800 cm3/min
Date
9/22/75
9/24/75
Average
Generator
sleeve
setting
800
600
800
600
Flow
cm^/min
856
289
856
289
861
294
861
294
Concentration,
ppm
0.328
0.273
0.246
0.215
0.330
0.284
0.246
0.216
Percent
difference
17
13
14
12
14
020«!CO«Ci»TR«TIO».,,«
Figure TT-1. Kl calibration curves for ozone at
sample flow rates of 300-400 cm3/min and 800
crnwmin.
100
-------
Based on this study, all field audits made during the period June 19 to Septem-
ber 5 were recalculated using a corrected set of values of 63 level versus sleeve
settings. Corrections were taken from Figure 11-1 using the 800 cm^/min flow data.
AUDIT RESULTS
Figures 11-2 to 11-4 are graphical representation of audit data by site. Audit
dates are arranged chronologically on the horizontal axis for a given site. The ver-
tical axis represents percent deviation of audited values from the Region I calibrator.
The average value of the deviations is indicated by a dot and the range of deviation
is indicated by the bar. A circle around the dot indicates audits made prior to June
19 and after September 5, 1975. The remaining values were all subjected to the cor-
rections explained above. An audit normally consists of four or five concentrations
between 0.08 and 0.3 ppm.
The following observations are offered on the data illustrated:
1. Within a given agency (e.g., Connecticut, Massachusetts, Rhode Island),
there is a high degree of self consistency.
2. It must be remembered that all data are referenced to the Region I calibration
system. This system is itself subject to variations, and hence some of the
divergent data could be accounted for by fluctuations in the auditing ozone
equipment.
3. Data in Figure 11-4 require special attention: In the case of New Hampshire
sites, no ozone generator was available to the agency, hence calibration of
a sensor was performed by transporting the KI calibration equipment into
the field. This procedure, in our experience, is subject to many sources of
error. In the case of the four groups collaborating in the Transport Study,
all contractors precalibrated ozone generators, then transported them 600
to 2000 miles and operated them for 2 months without benefit of laboratory
support^ Under these conditions, the degree of agreement must be consid-
ered good.
4. In support of the data adjustments discussed above, it is important to note
that data for Massachusetts and Connecticut include two audits in each set
(circled) that bracket the altered data (6/18-9/5/75) . The limited range
of variations within a given data set indicates that the modified data indeed
fit into each set.
5. Because different calibration teams are used at different sites (especially in
the case of Massachusetts) , it is not surprising that a certain amount of vari-
ation from site to site will occur. This could reflect calibration team exper-
ience as well as individual site instrument performance.
6. Averaging all audit values, a mean value (relative to Region I calibrator) is
-7.8 percent. A summary of audit data by collaborating groups is given in
Table 11-5.
An attempt was made to determine some of the reasons for variations between col-
laborating groups. In a telephone inquiry, the chemist or technician responsible for
KI calibration was asked specific questions about various points of analytical tech-
nique and data reduction. The responses are summarized in Table H~6. As discussed
101
-------
+ 15
C9
<
o
oc
NEW
HAVEN
HAMOEN MIODLETOWN ENFIELO WINDSOR EASTFORD
Figure 11-2. Ozone audit results at the Connecticut sampling sites.
102
-------
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Figure 11-3. Ozone auditsresults for Massachusetts and Rhode Island sampling sites.
103
-------
-5
-10 —
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(9
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Figure 11-4. Ozone audit results for special study participants and for New Hampshire sampling
sites.
104
-------
Table 11-5. SUMMARY OF AUDIT DATA BY GROUP
Group or agency
Connecticut
Massachusetts
Rhode Island
New Hampshire
Contractors
Average
Sum of percent diff .
+ 21.1
-233
- 93.4
- 75.8
- 200.5
Number of audits
24
24
9
4
13
Avg. percent diff.
+ 0.88
- 9.7
-10.4
- 18.9
-15.4
- 7.8
Table 11-6. VARIABLE PARAMETERS USED IN THE Kl CALIBRATION METHOD
Collaborator
EPA Region I
Same
6/18-9/5/75
Mass.
CN
Rl
NH
EPA-RTP
EPA-LVC
Battelle
WSU
NBS
UV cell
used,
mm
10
10
19
10
10
10b
10
10
10
10
Col lee.
device3
MWB
MWB
Ml
Ml
Ml
Ml
Ml
Ml
Ml
Ml
Collec.
flow
rate,
l/min
0.8
0.3-0.4
0.8
0.8
0.5
1.0
1.0
1.0
0.5
1.0
Concen.
range of
calibra.,
ppm
0.1 -0.3
0.1 -0.3
0.1 -0.3
0.04-0.12
0.1 -0.35
N.A.
0.02-0.1
0.1 -0.5
0.1 -1.0
0,1-0.5
Collec.
time,
min
10
10
10
10
10
10
10-30
15
15-30
10
Wasl2
curve
calcu.
by least
sq
Yes
Yes
No
No
Yes
No
No
Yes
No
Yes
Chemist
replying
E. Goffi
E. Goffi
J. Clements
D. Gregorsky
J. Cucco
A. Festa
R.Seila
C. Bennett
C. Spicer
E. Grimsrud
A. Hughes
aMWB--May West bubbler; Mi-midget impinger.
^Circular curvettes.
Calibration performed with long path UV photometer.
105
-------
above, the variation in flow rate in the Mae West bubbler used by Region I caused
a 14 percent difference in results. This point was checked by two groups (Massachu-
setts and Rhode Island) using their own midget impingers. Little or no variation in
collection efficiency with flow rate was experienced in the impingers. This tends to
verify the recommendation made by Research Triangle Park in their April 14, 1975
memo.
Where a low concentration range is used for calibration, several problems can
occur: Low values for absorbance increase the chances of error. Small variations
in the 12 calibration curve can cause sizeable error, especially when the slope is only
estimated and no intercept is taken into account. Where collection time exceeds 10
minutes, there is a well documented risk of losing some collection efficiency through
decay of the absorbing species with time.
In such a complex procedure, other parameters will also effect results, e.g.,
type of ultraviolet instrument used, chemicals employed for standards and titration,
impurities in the absorbing solution, etc. The present study points out a need to
further specify operational steps within a collaborating group. Such an effort is be-
ing proposed for the Region I collaborators prior to the 1976 ozone season.
INTERLABORATORY CALIBRATIONS
Two interlaboratory calibrations were performed comparing ozone generators
traceable to the National Bureau of Standards. On August 14, 1975, the Region I lab-
oratory equipment was taken to Greenwich, CN, to be compared with a calibrator used
by the Interstate Sanitation Commission (recently calibrated at NBS laboratories) as
well as one used by the state of Connecticut. Data on this calibration are shown in
Table 11-7. No attempt was made to precalibrate an on-site monitor used in this com-
parison . Each group simply fed four or five levels of ozone to the same monitor and
recorded the values obtained. As may be seen, the agreement between the three
calibrators was excellent.
Table 11-7. INTERLABORATORY CALIBRATION. GREENWICH, CN,
AUGUST 14,1975
Collaborator
Interstate Sanita-
tion Commission
Connecticut
EPA Region I
Sleeve
setting
900
700
500
300
150
Ozone
generator,
ppm
0.077
0.080
0.108
0.214
0.107
0.089
0.063
0.056
0.335
0.260
0.185
0.11
0.055
Ozone
monitor
response
0.071
0.074
0.10
0.208
0.094
0.080
0.059
0.048
0.288
0.225
0.162
0.098
0.052
Percent
diff.
- 7.8
- 7.5
- 7.4
- 2.8
-12
-10
- 6
-14
-14
-13
-12.4
-11
- 5.4
Average
percent
diff.
- 6
-10
- 8.2
106
-------
A second interlaboratory calibration was performed on an NBS calibrator. On
November 12, 1975, a calibrator was received at the Region I laboratory from NBS .
It was tested for 2 days using our KI method. Results were then compared to a cali-
bration curve sent under separate cover from NBS. Subsequently, the calibrator was
loaned to the states of Massachusetts, Connecticut, and Rhode Island and to a private
laboratory (Environmental Research Technology) to enable these groups to check
their KI techniques. Results of the tests are shown in Table 11-8. Data are calculated
oh percent difference (NBS-X) x 100. Each group worked without the NBS calibration
NBS
curve. Actual values were supplied at the termination of each study. Again, atten-
tion is drawn to the problem encountered with low levels of ozone. Only the ERT data
show good results at low 03 levels. This is so because an ozone monitor was used in
their test. Good linearity at both high and low levels is to be expected in such a test.
The generator supplied by NBS was not temperature controlled. Calibration was per-
formed at 25°C. Each collaboratory was asked to note room temperature during their
calibration runs. These temperatures are noted in Table 11-8. Each group noted
a variation of about + 1°C during their period of operation.
These interlaboratory calibrations indicate a high level of competence in the par-
ticipating laboratories. When the additional steps involved in field calibration are
taken into account, wider fluctuations must be expected. Here the range of variables
includes different calibration equipment, competence of field personnel, field instru-
ment stability, site suitability, and individual collaborator equipment performance as
well as variations in the audit team performance and equipment. It is this set of
variables which probably accounts for much of the variation found in Figure 11-1 data.
107
-------
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108
-------
12. SIMULATION OF OXIDANT AND PRECURSOR
TRANSPORT IN A SMOG CHAMBER
Lyman A. Ripperton
Research Triangle Institute
Research Triangle Park, NC
Figure 12-1 is a diagram of the Research Triangle Institute's smog chamber instal-
lation. The system is composed of four outdoor chambers (each 27 cubic meters in
volume) made of 5-mil FEP Teflon on aluminum frames. Each chamber has its own air
cleaning system to oxidize hydrocarbons and remove oxides of nitrogen (NOX) .
M (MMT)
Figure 12-1. Diagram of RTI Outdoor Smog Chamber.
The study reported here in brief was initiated, under Environmental Protection
Agency sponsorship, to study the behavior of 03 concentration under simulated con-
ditions of transport of oxidant and its precursors downwind from urban environs. To
simulate movement from the cities, chemical pollutant systems were irradiated for
multiple daylight periods and subjected to a period of dilution with clean air. Data
for three dilution rates are reported: 0.0 percent dilution (i.e., batch), 77.5 percent
dilution, and 95 percent dilution in 24 hours. After dilution, the chambers were run
in a batch mode with no additional dilution.
Initial reactant charges were 1 to 10 parts per million carbon (ppmC) of a surro-
gate urban mixture and 0.1 to 1.0 part per million (ppm) of NOX, of which 20 percent
was nitrogen dioxide (NO2) • The nonmethane hydrocarbon (NMHC) to NOX ratios
were chosen to be from 7 to 20.
109
-------
The results of the study have been summarized, in part, in a series of tables
similar to Table 12-1. The first four columns after the data and chamber number pro-
vide information about the first day's behavior of the system. This series of runs was
diluted 95 percent for 24 hours starting at the time of NOX crossover (at about 0830) .
In chamber 1, the NMHC charge was about 7 ppmC and the NOX was about 1.0 ppm
with a ratio of 7. Maximum ozone (03) concentration in chamber 1 was about 1.1 ppm
the first day. The next column indicates whether the following data are from the
second or third day of irradiation. The NOX concentrations at sunrise were in the
part per billion (ppb) range. The NMHC/NOX ratios were high; for the whole set of
experiments, they ranged from 27 to over 300. On the second and third days, gas
chromatographic analysis of the remaining hydrocarbons showed a preponderance of
alkanes and aromatic compounds, with alkenes virtually exhausted except for a few
tens of parts per billion of ethylene that usually remained.
The maximum 03 concentrations obtained in the second and third days were, in
most cases (in all cases in Table 12-1) , above the National Ambient Air Quality Stand-
ard (NAAQS) for photochemical oxidant. The net O^ concentrations generated (i.e. ,
the difference between the morning minima and the afternoon maxima) were also al-
most all greater than the NAAQS despite extremely low NOX concentrations.
Table 12-2 represents another type of summary and analysis of the O^ generative
data from the second and third days of irradiation. In Table 12-2, both the NOX data
and the NMHC/NOX ratios have been stratified by numerical range and the net Oj con-
centrations associated with a particular combination have been listed in the appropri-
ate squares. Averages of individual boxes, vertical columns, and horizontal rows,
are indicated. Although not illustrated, the same treatment was afforded the maximum
03 concentrations and then both the net 03 and the maximum 03 concentrations were
compared for various combinations of NMHC concentration range and NMHC/NOX ratios.
Ranges of NOX and NMHC concentration were arbitrarily selected to provide a spread
of ratios. These indicated comparisons are plotted in Figures 12-2 to 12-4.
In Figure 12-2, it can be seen that maximum, minimum, and net 03 concentration
increased with increasing NOX. As the maximum 03 concentration increased, so did
the minimum. The divergence between maximum and net 03 concentrations as the
NOX concentration increased was due to 03 left over from the day before. A similar
phenomenon with increasing NMHC concentrations can be seen in Figure 12-3.
In Figure 12-4, 03 concentration was plotted against NMHC/NOX ratios. Here
there was a maximization of 03 concentration (both maximum and net) in the 55 to 99
ratio range.
A so-called "dilution effect" on 03 generation was mentioned in an earlier presen-
tation . It has previously been noted by others that a reduction in initial concentrations
of reactants (at the same ratio) did not produce a proportional reduction in the sub-
sequent 03 maximum. Similar phenomena have been observed under dynamic dilution
in this study. An example employing second day data is illustrated in Figure 12-5.
Similar initial concentrations and conditions of solar irradiation existed in the three
cases. As can be seen, a 95 percent dilution of the system in 24 hours (ending about
0830 on the second day) produced only a 40 percent reduction in maximum 63. The
net O3 generated in the 95 percent dilution (0.26 ppm) was actually greater than the
net generated in the batch system (0.20 ppm) . The efficiency of 63 generation (per
NOX molecule) is increased by dilution,. This so-called dilution effect is one of the
processes helping to deliver high 03 concentrations to nonurban areas.
110
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111
-------
Table 12-2. NET OZONE GENERATED ON SECOND AND THIRD DAYS OF IRRADIATION
AS A FUNCTION OF OXIDES OF NITROGEN AND NONMETHANE HYDROCARBON/OXIDES
OTNITROGEKTRATTO
Range
,NMHC (ppmC)
NOX IppmT
0-49
50-99
100-199
200
Average
ozone
NOX range, ppb
1 -5
0.201
Avg. 0.201
0.1 52a 0.1 23a
0.21 7a 0.054a
0.1 53a
Avg. 0.140
0.076 0.173
0.206 0.129
0.172 0.1 25a
Avg. 0.147
0.149
6-8
0.124*
0.131*
Avg. 0.128
0.263 0.257a
0.2503 0.0683
0.1 50a
Avg. 189
0.171
9-14
0.195 0.1 82a
0.115
/ Avg. 0.164
0.312 0.190*
0.256 0.119*
0.230 0.177*
0.214
Avg. 0.21 4
0.123 0.033
0.094 0.2853
Avg. 0.1 34
0.180
15-53
0.181
0.154
Avg. 0.168
0.365 0.344*
0.300
0.197
0.371
Avg. 0.315
0.150 0.238a
0.135 0.2283
Avg. 0.188
0.241
Indicates third day values.
A term "fossil" 03 has been coined (and should now be abandoned) to denote 03
which is generated in urban environs and then drifts for some distance downwind.
Prodigious distances of translation for undiminished 03 levels are implied.
In order to see what light the smog chamber data shed on this phenomenon (i.e. ,
the possible duration of 03 in a spent and non-O3~generating system) , the nighttime
half-lives of 03 were calculated in chambers at a time when they were not undergoing
mechanical dilution. Results are shown in Table 12-3. Maximum 03 levels of the pre-
vious day are shown, and half-lives were calculated using the 0200 and 0500 concen-
trations. The table shows the 0200 concentrations and the calculated half-lives.
Half-life was calculated by removing the dark-phase clean chamber 63 destruc-
tion rate constant (ks) . Assuming first order decay, half-life may be calculated as
follows:
112
-------
E
a.
a.
10
O AVERAGE 03 MAXIMA
• AVERAGE 03 MINIMA
DAVERAGE A03
20 30
OXIDES OF NITROGEN, pgb
40
50
Figure 12-2. Average maxima, minima, and AOs concentrations as function of NOX concen-
trations at sunrise on second and third days of irradiation.
ktt =
t =
k =
k =
kg =
£n
C0200
CQ500
3 hours
(k
kg)
rate constant for 03 destruction due to reaction with the chamber plus
reaction with pollutant contents of the chamber (calculated)
rate constant for 03 destruction by the chamber determined from 03 -
clean air mixtures in the dark
gas phase destruction of 03 by contents of the experimental pollutant
system
k* - k0
£n2
kg
Of the 24 values listed, 17 are below 20 hours, 5 others are below 60 hours, and 2 are
rather large, 265 and 450 hours. The only field data the author has from which to
113
-------
.60
.50
.40
.30
.20
.10
O AVERAGE 03 MAXIMA
• AVERAGE 03 MINIMA
D AVERAGE A03
0.50
1.00 1.50
NMHC, ppm
2.00
2.50
3.00
Figure 12-3. Average maxima, minima, and AC>3 concentrations as function of nonmethane
hydrocarbon concentrations on second and third days of irradiation.
make an estimate of the dark phase half-life are shown in Figure 12-6. A series of
vertical 03 concentration profiles were taken with an aircraft on August 1, 1974, at
Wilmington, OH. To obtain a rough estimate of what the 63 half-life might have
been, it was assumed that the profile at 0700 on August 2 was the same as that at 0700
on August 1 . Assuming a first order decay from 1700 August 1 to 0700 August 2 , the
calculated 63 half-life was 29 . 5 hours .
With half-lives of 20 to 30 hours, the amount of 0| left ever OR the felipwifl§
ing can provide a high minimum on which to build a high ffl&xifflUHi l©r the day . WHh
half-lives of 20 to 30 hours, however, a parcel of go-called "fossil" 63 cannot ftiaifi-
tain high concentrations for more than a day or two without augmenting synthesis .
Chamber data of the second and third day are remarkably similar to field data .
A major difference in the two kinds of systems was that after the initial charge no
114
-------
0.40-
0.30
IO
o o.
20-
0.10
O AVERAGE Qj MAXIMA
AVERAGE A0«
0 '
0 50
Figure 12-4. Average maxima
nitrogen ratio.
.14
.12
.10
E .08
a,
a.
K> .06
O
.04
.02
.00
itiir
100 ISO 200 250 300
NMHC/NOX , ppmC/ ppm
and A 03 as function of nonmethane hydrocarbon to oxides of
I_ • August 13 - Batch 0% Dilution • July 29 - 95% Dilution
_ 03 Minimum 0.53 ppm 03 Minimum 0.02 ppm
— 03 Maximum 0.72 ppm 03 Maximum 0.29 ppm
- A03 0.20 ppm A03 0.26 ppm
- A August 9 - 77% Dilution
— 03 Minimum 0 . 10 ppm
— 03 Maximum 0.40 ppm
— A(Vj 0.30 ppm
I"'-.
- '•
-_
-::-".
- I l*i*l»l«l
-•••••
• • ' • •
•• . •
A A A A
** • t * * A
A * •
•l«l«l 1 1 i I 1 1 I 1 1 1 1 1 1
0200 0400 0600 0800 1000 1200 1400 1600 1800 2000 2200 2400
TIME (HOURS-EOT)
Figure 12-5. Ozone profiles over second day irradiations for same initial conditions and different
dilutions in chamber 1.
115
-------
Table 12-3. DARK-PHASE OZONE HALF-LIVES IN SMOG CHAMBER RUNS
Date
July 24
July 30
August 6
August 10
August 13
August 14
Experimental type
Dilution 95% a
Initiated at 1700
Dilution 95%
Initiated at NOX
crossover
Dilution 77%
Initiated at NOX
crossover
Dilution 77%
Initiated at NOX
crossover
Batch
Batch
Chamber
number
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
Max. [03] previous day,
ppm
0.185
0.138
0.119
0.089
0.286
0.212
0.214
0.175
0.479
0.366
0.350
0.214
0.400
0.293
0.288
0.179
1.378
0.886
0.997
0.549
0.724
0.525
0.786
0.336
[03] at 0200,
ppm
0.066
0.048
0.038
0.025
0.102
0.085
0.076
0.083
0.311
0.243
0.213
0.109
0.218
0.175
0.150
0.109
0.776
0.561
0.567
0.415
0.422
0.333
0.352
0.252
Half-life (t1/2),
hr
4.3
3.6
11.6
13.3
6.4
6.2
7.4
7.8
14.9
11.6
10.0
7.1
16.6
14.2
19.2
14.2
33.5
42.9
50.3
265.4
19.9
27.2
54.5
449.6
aMechanical dilution had been terminated prior to the time periods chosen for half-life calculations.
additional reactants were added to the chamber. To compare actual field conditions
with second and third day smog chamber data, observe Figures 12-7 to 12-12.
Figure 12-7 depicts diurnal curves drawn from hourly 03 averages at three Ohio
stations in the summer of 1974. Note that the maxima are between 0.07 and 0.08 ppm,
indicating that many of the individual concentrations making up the hourly averages
were over the NAAQS. The time of maxima at the rural station was shifted more to-
ward sundown than in city diurnal curves. Also the slope of the 63 destructive side
of the curve is less steep than the 63 synthesis side of the curve. This is not general-
ly the case in urban diurnal curves and can be attributed to the fact that in a relatively
spent photochemical system out of touch with fresh pollutants (as auto exhaust in even-
ing rushhour traffic) the 03 destructive agents are depleted.
Figure 12-8 depicts the hourly averages of NOX from the field obtained at the same
time and in the same areas as the 63 data in Figure 12-7. The NOX concentrations
ranged from about 2 to 12 ppb. Smog chamber second and third day values were 1 to
53 ppb. Calculated from average data, the NMHC/NOX ratios were 27 to over 300.
Figures 12-9 to 12-12 compare field and chamber data graphically. Figure 12-9
contains the data from the first day of a smog chamber run in which there was no dilu-
tion. The data of the second and third days (Figures 12-10 and 12-11) both achieved
maximum 03 concentrations and net 03 generation well over the NAAQS.
116
-------
~ 3.01-
o
M
2E 2.4-
CO
o
3
1.8
1.2
0.6-
1754 /I4I4
0704
0.05
0.075 0.10
°» ppm
0.125
Figure 12-6. Vertical ozone soundings at Wilmington, Ohio, on August 1, 1974.
117
-------
0.0* r
• MCCONNELSVILLE
o WOOSTER
• WILMINGTON
0.00
0700 0900 1100 1900 1500 I7OO 1900 2100 MOO 0100 OSOO 060O OTOO
TIME (HOURS-EST)
Figure 12-7. Mean diurnal 63 concentration ^t^Wi|mington, Wooster, and McConnelsville,
Dh 10, TrorrF~ "
14
12
10
i 6
A
J t
>v \
I i
I
o WILMINGTON
o WOOSTER
• MCCONNELSVILLE
J
0700 0900 HOO 1300 1800 1700 1900 2100 2300 0100 0300 0500 0700
TIME (HOURS-EST)
Figure 12-8. Mean diurnal NOo concentration at Wilmington, Wooster, and McConnelsville, Ohio,
from June 14 to August 31, 15(74.
118
-------
1 .%}
1.3
1.2
1.1
1.0
cJ 0-9
z 0.8
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c? 0.5
0.1
0.3
0.2
0.1
n n
-1 1 '
—
—
—
_
—
—
—
, | , | , | , |. |, | ,| , ,, | , , , | , | ,
O NO, ppm
A N02, ppm X
X 03, ppm x
° a A x
A A
a a
A
A X
A
A A A A A D A
L Iw Iw Iw Iw Ulw-LUiLld U L IH
1 , , i 1 i 1 , 1 . I i 1 . 1 . 1 ._
x $/12 #1 STflTIC ~
x
x —
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iL
—
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U-ld-UJd.idJd-ld Id Id"
i . 0
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0.9 z
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0.6 °
0.5
0.1
0.3
0.2
0.1
n n
012315678 91011121311151617181920212223
TIME OF DRY
Figure 12-9. First day chamber concentration profiles.
o
Z
o
z
1^
0
1 5
1*O
l.f
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.1
0.3
0.2
0.1
n n
_,,.,. 1 . 1 . 1 • 1 i 1 ,
— D NO, ppm
L. A N02, ppm
2_ X °3.PPm
X
— X
:_ x x x
—
—
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—
^^^
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H IH IH U IH IH IH IH
_ _ _ _ __ ___ — _.„ _ - - - _ __. „.
. , . , . 1 . , . 1 . 1 . 1 , , , , . 1 , , . , . , . 1 . 1 ._
8/13 fl STflTIC ~
^_
—
—
— ^_
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—
v X X x
X X
x x x x _I
x x x x x xl
—
—
—
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A lA |A iA iA lA iA lA |A IA IA lA IA IA IA 1 A—
H ^H 'H 'H *H 'H 'r\ 'H 'r\ 'H 'n 'n 'n 'n ^n 'n
123^5678 910111213H151617181920212223
TIME OF DflY
Figure 12-10. Second day chamber concentration profiles.
1
1
1
1
1
1
0
0
0
0
0
0
0
0,
0.
0.
3
2
1
8 P
7 z
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1.3
1.2
1.1
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0.9
0.8
0.7
0.6
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0.3
0.2
0.1
n n
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—
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8/H #1 STflTIC "I
D NO, ppm _
A N02. ppm _2
X 03, ppm
—
—
—
—
x x -
x _I
X X v, X —
V
x y X —
X X X
—
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122
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13. OZONE TRANSPORTED TO NANTUCKET, MA
OCTOBtR 1975
Thomas J. Kelleher, Jr., William A. Feder,
William D. Riley, and Irving Perkins
Suburban Experiment Station
University of Massachusetts
Waltham, Massachusetts, U.S.A.
Plants of Bel-W3 tobacco, a plant easiiy injurec by ozone, were used in conjunc-
tion with Mast oxidant meters to confirm that oxidants occurring on Nantucket during
the summer of 1975 were from a distant source. The oxidant, probably ozone, was
maximal on southwest winds with very little ozone transported to Nantucket Island on
east and northeast winds. Since Nantucket has no means of producing the high levels
of ozone indicated by the Mast meters and plants that were positioned across the is-
land, a likely source may-be the urban areas about 200 or more miles over ocean to
the southwest.
Ozone flecking of Bel~W3 tobacco has been shown to have a direct correlation with
hours of ozone higher than 0.04 ppm if a sufficient number of plants are used in a grid
system. Using Nantucket Island as a single grid with nine areas of tobacco plants a-
cross it, the direct correlation with daylight hours of ozone was confirmed. Nantucket
experienced 260 daylight hours (6 a.m. to 9 p.m.) with ozone concentrations ,>0.04
ppm and 351 hours of night-time ozone (10 p.m. to 5 a.m.) >. 0.04 ppm. All ozone
levels above 0.06 ppm between June 3 and August 12, 1975, occurred when the winds
were from the southwest.
INTRODUCTION
Oxidant injury to plants has been well documented, especially for urban areasr'^
The major constituent of high oxidant levels in the atmosphere is probably ozone,
which was commonly thought to be relatively labile.3.4
Bel-W3 tobacco plants are widely used as indicators of ozone pollution, but sev-
eral previous studies report that the relationship between oxidant doses and injury to
tobacco leaves is nonlinear. 5,6 ^ grid layout of tobacco plants has been used in pre-
vious work, which showed that leaf damage and hours of ozone greater than 0.04 ppm
were linearly related, if a sufficient number of tobacco plants are distributed in a grid
formation over an area at least 0.5 mile in diameter. The grid system seems to elimi-
nate the large deviations observed between individual plant responses to ozone. ?
The study reported here was conducted on Nantucket Island, MA, an island 30
miles to the southeast of Woods Hole, MA, and about 200 miles to the northeast of the
Middle Atlantic States. The objectives of the study were: (1) to demonstrate long-
range transport of ozone, and (2) to evaluate tobacco injury due to ozone using a grid
layout. This was the first large-scale field test of that system.
MATERIALS AND METHODS
Seeds of the Bel-W3, ozone-sensitive, tobacco were grown in a charcoal filtered
air chamber for a period of 6 weeks. The plants were then transplanted into uniform,
123
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steamed soil at nine areas on Nantucket Island on June 5, 1975. The areas each con-
sisted of three points containing at least three plants at each point. The tobacco plants
were observed from June 5 to August 11, 1975. All plants were shaded (approximate-
ly 50 percent) , watered, and fertilized. The injury due to ozone on each leaf was
scored weekly by inspection of area flecked.
Ozone was monitored with a calibrated Mast oxidant meter fitted with strip chart
recorders, and hourly maximums were recorded. Mast devices were placed on the
opposite ends of Nantucket. The ozone levels were correlated to wind direction,
which was monitored on a standard anemometer positioned approximately 40 feet above
sea level at Quaise (middle-north location on the Island) .
The mean and standard deviation of percent leaf injury for all nine areas of the
grid were related to the number of daylight hours (6 a.m. to 9 p.m.) during which
the maximum ozone level equaled or exceeded 0.04 ppm.
RESULTS
The wind rose of Figure 13-1 points out the predominance of southwest winds dur-
ing the study period. The figure also relates wind direction to the cumulative hours
of ozone .> 0.04 ppm. The ozone transport on southwest winds is clearly seen when
compared to the lack of ozone transported to the island from the east. Table 13-1 in-
dicates that the cumulative hours of ozone .> 0.04 ppm were more frequent at night
(10 p.m. to 5 a.m., with 351 hours) than during the day (6 a.m. to 9 p.m., with
260 hours) . The total for the study period was 611 hours. The highest single hourly
ozone level was 0.205 ppm, with levels over 0.08 ppm common on southwest winds.
Table 13-2 relates increasing plant injury at individual areas to increasing cumula-
tive daylight hours of ozone _>0.04 ppm. The linearity of the data in Table 13-2 is
illustrated in Figure 13-2.
WIND ROSE
250
150
50
x-AXIS, WIND DIRECTION
y-AXIS, CUMULATIVE HOURS >0.04
ppm OZONE
N NE E SE S SW W NW
Figure 13-1. Wind rose (left) showing wind directions of June, July, and
August 1975. Cumulative hours of ozone related to wind direction (right)
shows the predominance of ozone transported to Nantucket Island, MA,
from the southwest.
124
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Table 13-1. CUMULATIVE HOURS DURING WHICH
OZONE LEVELS WERE > 0.04 ppm
2 hours
Daylight hours (6 a.m. to 9 p.m.) of ozone
Night hours (10 p.m. tolTa.m.} of ozone
Total hours of ozone
260
351
611
DISCUSSION
The appropriately calibrated Mast
oxidant meters confirmed that there
were no detectable sources of ozone
pollution on Nantucket Island itself.
The two Mast meters and the nine-area
tobacco plant grid did indicate the
presence of frequently occurring high
concentrations of ozone. The linearity
of the plant injury due to ozone was
based on daylight hours of ozone, since
plants seemed to be susceptible to injury from ozone only when the stomata were open.^
The linear relationship between plant injury and hours of ozone 2 0.04 ppm developed
by the use of the grid system? appears to be reproducible. The slopes of these rela-
tionships do vary, but not significantly, and at this time no concrete explanation for
this variation can be given.
The evidence for the presence of ozone on Nantucket, when related to the record-
ed wind directions, suggests that a likely source for the majority of ozone was the ur-
ban areas about 200 miles or more to the southwest of Nantucket. Furthermore, since
Table 13-2. CUMULATIVE DAYLIGHT HOURS (6 a.m. to 9 p.m.) OF OZONE >0.04 ppm,
AND MEAN PERCENT PLANT INJURY DUE TO OZONE AT EACH AREA OF THE GRID
Date
5/9/75
5/16/75
5/23/75
5/30/75
6/11/75
6/22/75
6/30/75
7/6/75
7/11/75
Hours of ozone > 0.04
27
55
- 72
79
140 ~'
154
208
250
260
Mean percent plant injuries at nine areas3
I
1
5
6
9
25
22
39
52
52
II
0
2
12
14
32
41
48
52
III
2
11
14
18
40
38
59
62
51 j 73
IV
0
3
15
21
39
43
56
66
59
V
0
1
12
13
39
40
55
55
54
VI
2
8
12
18
28
31
34
40
54
VII
3
9
10
16
31
39
37
52
48
VIII
0
3
4
5
25
27
38
42
50
IX
4
11
12
14
26
32
30
53
48
?Mean percent injury for nine plants per area. Area names and locations:
I. U.S.C.G. Loran Station (SE) VI.
II. Shimo (middle, N) VII.
III. Ram Pasture (SW) VIM.
IV. Squam (NE) IX.
V. Mile Stone Road (middle)
Bartlett Farm (SSW)
Univ. of Mass., Quaise (N)
M.S.P.C.A. Reserve (IMW)
Nantucket Cranberry Co. (middle, E)
125
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50
100
ISO
200
250
CUMULATIVE HOURS OZONE
OVER 0.04 ppm
Figure 13-2. Percent leaf injury of Bel-W3 relates linearly
to the daylight hours of ozone > 0.04 ppm.
ozone is produced by a photoreaction of hydrocarbons and nitrogen oxides, the com-
mon night-time occurrence of ozone supports the contention that ozone is produced in
the light and later transported to the island by wind. The long range transport of
ozone might be considered in relation to the surface over which the ozone is being
transported. This study confirms that ozone is capable of long raftge^alas^ort ever
the ocean surface, but the range of ozone transport may be quite different over a for-
est or a mountain range.
Communities and others interested in local air quality, but unable to afford the
cost of buying and maintaining monitoring equipment, might be able to utilize a grid
system of tobacco plants for a semi-quantitative estimate of daylight hours of ozone.
A proper set of standard curves should be developed for this purpose. The concept
of using plants as air quality monitors may even have advantages over a single pur-
pose monitoring device. A plant is capable of integrating many subtle variations in
any given microenvironment and, therefore, is measuring the true quality of its en-
vironment rather than a single aspect or substance in that environment.
REFERENCES
1. Middleton, J.T. Photochemical Air Pollution Damage to Plants. Ann. Rev. of
Plant Physiol. 12:483-448, 1961.
2. Heck, W.W. Factors Influencing Expression of Oxidant Damage to Plants. Ann.
Rev. Plant Physiol. 6:165-188, 1968.
3. Jaffe, L. S. Effects of Photochemical Air Pollution on Vegetation with Relation to
the Air Quality Requirements. J. Air Pollut. Contr. Ass. 17: 38-42, 1967.
4. Stephens, E.R. Chemistry of Atmospheric Oxidants. J. Air Pollut. Contr. Ass.
19:181-185, 1969.
126
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5. Heck, W.W. andD.T. Tingey. Time Concentration Model to Predict Acute Foliar
Injury. Proc . 2nd Int. Clean Air Congress . 1970. p.249~255.
6. Jacobson, J.S. and W.A. Feder. A Regional Network for Environmental Moni-
toring: Atmospheric Oxidant Concentrations and Foliar Injury to Tobacco Indi-
cator Plants in the Eastern United States. Bull. 604, Mass. Agric. Exp. Station,
Coll. of Food & Natl. Resources, University of Massachusetts at Amherst. 1974.
7. Riley, W.D., K. Moeller, I. Perkins, and W.A. Feder. Evaluation of Tobacco
>• Plants as Biological Monitors of Oxidants. Proc. Fall Tech. Meeting of N .E.
Section A.P.C.A., Falmount, MA. 1974. p. 92-99.
127
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ATTENDANCE LIST
Kenneth Hagg
Massachusetts Department of
Environmental Quality Engineering
Boston, MA
Alan Eschenroeder
Environmental Research and
Technology, Inc.
Santa Barbara, CA
Helen McCammon
Environmental Protection Agency
Region I
Boston, MA
John W. Shiller
Ford Motor Company
Dearborn, MI
Tai Y. Chang
Ford Motor Company
Dearborn, MI
W.J. Koehl
Mobil Oil Research and Development
Corp.
Paulsboro, NJ
Robert Frankhauser
Environmental Protection Agency
Research Triangle Park, NC
Bruce Carhart
Environmental Protection Agency
Region V
Chicago, IL
R.A. Rasmussen
Washington State University
Pullman, WA
J.A. Anderson
Meteorological Research, Inc.
Altadena, CA
L.L. Spiller
Environmental Protection Agency
Research Triangle Park, NC
Robert Arnts
Environmental Protection Agency
Research Triangle Park, NC
Robert L. Seila
Environmental Protection Agency
Research Triangle Park, NC
Emmet Jacobs
DuPont Petroleum Lab.
Wilmington, DE
Thomas R. Powers
EXXON Research and Engineering Co.
Linden, NJ
J.M. Pierraro
E.I. Dupont Corp.
Wilmington, DE
John L. Pearson
Environmental Protection Agency
Research Triangle Park, NC
Richard Angus
Environmental Protection Agency
Research Triangle Park, NC
Mark Scruggs
Florida State University
Tallahassee, FL
Jim Worth
Research Triangle Institute
Research Triangle Park, NC
Rich Kamens
University of North Carolina
Chapel Hill, NC
Art Spratlin
Environmental Protection Agency
Kansas City, MO
Bob Chanslor
Environmental Protection Agency
Region VII
Kansas City, MO
Region VH
128
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Lewis Nagler
Environmental Protection Agency
Region IV
Atlanta, GA
Martin Ferman
General Motors Research Lab.
Warren, MI
Pete Groblicki
General Motors Research Lab.
Warren, MI
Gary Whitten
Systems Application, Inc.
San Raphael, CA
Ship Burton
System Application, Inc.
San Raphael, CA
Tim Belian
Coordinating Research Council
New York, NY
Richard Kuntz
Environmental Protection Agency
Research Triangle Park, NC
Rod S. Spindt
Gulf Oil Corp.
Pittsburgh, PA
Charles R. Hosier
Environmental Protection Agency
Research Triangle Park, NC
J. Romanosky
Environmental Protection Agency
Research Triangle Park, NC
A.M. Ellison
Environmental Protection Agency
Research Triangle Park, NC
Clif Decker
Research Triangle Institute
Research Triangle Park, NC
Don L. Fox
University of North Carolina
Chapel Hill, NC
L.A. Ripperton
Research Triangle Institute
Research Triangle Park, NC
Marijon Bufalini
Environmental Protection Agency
Research Triangle Park, NC
H.E. Jeffries
University of North Carolina
Chapel Hill, NC
T.G. Ellestad
Environmental Protection Agency
Research Triangle Park, NC
Ronald Patterson
Environmental Protection Agency
Research Triangle Park, NC
Barry Martin
Environmental Protection Agency
Research Triangle Park, NC
L.W. Chancy
University of Michigan
Ann Arbor, MI
E.L. Martinez
Environmental Protection Agency
Research Triangle Park, NC
Phillip Youngblood
Environmental Protection Agency
Research Triangle Park, NC
F .L. Ludwig
Standford Research Institute
Menlo Park, CA
Irv. Leichter
Geomet Inc.
Gaithersberg, MD
Ted Winfield
Environmental Protection Agency
Research Triangle Park, NC
Marcia Dodge
Environmental Protection Agency
Research Triangle Park, NC
129
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Gordon Ortman
Environmental Protection Agency
Research Triangle Park, NC
A.P. Altshuller
Environmental Protection Agency
Research Triangle Park, NC
Ken Demerjian
Environmental Protection Agency
Research Triangle Park, NC
Bruce Gay
Environmental Protection Agency
Research Triangle Park, NC
Joseph J. Bufalini
Environmental Protection Agency
Research Triangle Park, NC
George Wolff
Interstate Sanitation Commission
New York, NY
Hal Westberg
Washington State University
Pullman, WA
Chet Spicer
Battelle Memorial Institute
Columbus, OH
Karl Zeller
Environmental Protection Agency
Las Vegas, NE
Donna Morris
Environmental Protection Agency Region I
Boston, MA
Robert Whitby
New York State Dept. of Environmental
Conservation
Albany, NY
George Siple
Environmental Protection Agency
Las Vegas, NE
William Lonneman
Environmental Protection Agency
Research Triangle Park, NC
Bruce Bailey
Texaco, Inc.
Beacon, NY
130
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TECHNICAL REPORT DATA j
(Please read Instructions on the reverse before completing)
;1 REPORT NO. 2.
I EPA-600/3-77-017
4 TITLE AND SUBTITLE
PROCEEDINGS OF SYMPOSIUM ON 1975 NORTHEAST OXIDANT
TRANSPORT STUDY
-
7 AUTHOR(S)
Joseph J. Bufalini and William A. Lonneman (editors)
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Environmental Science Research Laboratory
Office of Research and Development
'J.S. Environmental Protection Agency
Research Triangle Park, NC 27711
12. SPONSORING AGENCY NAME AND ADDRESS
Environmental Science Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
3. RECIPIENT'S ACCESSI OI*NO.
5. REPORT DATE ',
February 1977
6. PERFORMING ORGANIZATION CODE !
i
8. PERFORMING ORGANIZATION REPORT NO ;
i
10. PROGRAM ELEMENT NO. I
1A603 !
11. CONTRACT/GRANT NO.
' I
13. TYPE OF REPORT AND PERIOD COVERED >
Final I
14. SPONSORING AGENCY CODE I
EPA/600 $9
15. SUPPLEMENTARY NOTES 1
1
16. ABSTRACT • \
The nreliminarv results of the 1975 Northeast Oxidant Transport Study were presented 1
by the participants of the study at a symposium held at the Environmental Research
Center in Research Triangle Park, NC, on January 20-21, 1976. The participants
included the Environmental Protection Agency's Environmental Sciences Research
Laboratory, EPA Region I, EPA Las Vegas, Battelle Columbus, Washington State Univer-
sity, Interstate Sanitation Commission, New York State Department of Environmental
Conservation, and the University of North Carolina. Discussed were preliminary re-
sults of ozone measurements collected during a study conducted to investigate trans-
port phenomena in the Northeastern United States. The study was undertaken to in-
vestigate the extent and importance of transport in this densely populated area.
The ultimate purpose of the study was to provide the necessary information needed to
determine the suitability of present control strategy.
17. KEY WORDS AND DOCUMENT ANALYSIS 5
a. DESCRIPTORS
*Air Pollution
*0zone
*Atmospheric circulation
*Field Studies
18. DISTRIBUTION STATEMENT
RELEASE UNLIMITED
b. IDENTIFIERS/OPEN ENDED TERMS
Northeastern U.S.
19. SECURITY CLASS (This Report)
UNCLASSIFIED
20. SECURITY CLASS /This page)
UNCLASSIFIED
c. COSATI Held/Group •
13B |
07B
04B !
14B !
21. NO. OF PAGES I
145 1
22. PRICE J
EPA Form 2220-1 (9-73)
131
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