EPA-650/3-74-005
PRECIPITATION SCAVENGING
OF INORGANIC POLLUTANTS
FROM METROPOLITAN SOURCES
by
M.T. Dana, J.M. Hales,
C.E. Hane, and J.M. Thorp
Atmospheric Sciences Dept. , Battelle,
Pacific Northwest Laboratories
P.O. Box 999
Richland, Washington 99352
Interagency Agreement No. IAG-D4-0323
Program Element No. 1AA009
EPA Project Officer: Herbert Viebrock
Meteorology Laboratory
National Environmental Research Center
Research Triangle Park, North Carolina 27711
Prepared for
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
June 1974
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This report has been reviewed by the Environmental Protection Agency
and approved for publication. Approval does not signify that the
contents necessarily reflect the views and policies of the Agency,
nor does mention of trade names or commercial products constitute
endorsement or recommendation for use.
11
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CONTENTS
Page
ABSTRACT iv
LIST OF FIGURES v
LIST OF TABLES vii
ACKNOWLEDGEMENTS viii
SECTIONS
I. CONCLUSIONS 1
II. RECOMMENDATIONS 2
III. INTRODUCTION 3
IV. MODELING OF SCAVENGING BY CONVECTIVE STORMS 7
V. EXPERIMENT DESIGN 25
VI. EXPERIMENTAL RESULTS: AUGUST, 1972 37
VII. ANALYSIS OF RESULTS 63
VIII. REFERENCES 85
IX. NOMENCLATURE 87
X. APPENDICES 91
iii.
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ABSTRACT
This report describes initial results of a program to measure and model
the precipitation scavenging of urban pollutants in the St. Louis area.
The primary field measurements of the program are of concentrations of
trace inorganics (H , SO? , SO , NH , NO ~, N0~) in rainwater collec-
i5 5 5 a o
ted at specific locations in the area. These, along with supporting field
measurements, will be used to formulate and verify mathematical models of
scavenging which will subsequently be employed as components of an over-
all model developed by the Environmental Protection Agency's Regional Air
Pollution Study.
A review of possible field experimental designs in the context of the
modeling objectives of this study indicates that the concept of a regional
pollution material balance is an appropriate initial approach. The scav-
enging term in the balance is the scavenging rate, the mass of a given
pollutant removed per unit distance (along the storm path) per unit time.
These rates were computed from the concentrations measured during five
conveotive storms in August, 1972. For one storm, where scavenging rates
were determined at three distances from the city, the derived downstorm
removal rates (mass per unit time) for sulfate and nitrate were comparable
in magnitude to estimates made of the urban area emission rates.
This report is submitted in fulfillment of work specified in proposal No.
300A00584 (BNW-389), Amendment 4, by Battelle, Pacific Northwest Labora-
tories, under the sponsorship of the Environmental Protection Agency.
Work was completed as of July, 1973.
iv.
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FIGURES
Page
1. Simplified Schematic of RAPS Model 4
2. Schematic of Cumulonimbus Cloud 8
3. Wind Shear Structure of Cumulonimbus Cloud 10
4. Updraft and Downdraft Interactions in Cumulonimbus Cloud . . 12
5. Material Balance Schematic for Washout Ratio Analysis. ... 15
6. Schematic Representation of May's^ Model 19
7. Schematic for Macroscopic Storm Cell Model 21
8. Schematic of Overall Regional Material Balance 26
9. Precipitation Sampling Array: August 1972 30
10. Freezing Precipitation Sampler 33
11. Rainfall Map, Run 1 42
12. National Weather Service Radar Echo Maps, Run 1 43
13. Radiosonde Results, 1402 CST, August 19, 1972 45
14. Rainfall Map, Run 2 46
15. National Weather Service Radar Echo Maps, Run 2 47
16. Radiosonde Results, 0938 CST, August 20, 1972 48
17. Radiosonde Results, 1430 CST, August 20, 1972 49
18. Rainfall Map, Run 3 51
19. Radiosonde Results, 1417 CST, August 21, 1972 53
20. Rainfall Map, Run 4 54
21. National Weather Service Radar Echo Map, Run 4 55
22. Radiosonde Results, 1025 CST, August 25, 1972 57
23. Radiosonde Results, 1501 CST, August 25, 1972 58
24. Aircraft Sounding Results for S02 Air Concentrations,
August 16, 1972 60
v.
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Page
25. Rainfall and Rain Pollution Fluxes, Runs 1 and 2 69
26. Rainfall and Rain Pollution Fluxes, Run 3 70
27. Rainfall and Rain Pollution Fluxes, Run 4, Line A .... 71
28. Rainfall and Rain Pollution Fluxes, Run 4, Line B . . . . 72
29. Rainfall and Rain Pollution Fluxes, Run 4, Line C . . . . 73
30. Component of the Wind in the Plane of Motion of the Storm
as a Function of Height for the 21 August 1972 Storm ... 79
31. Time Evolution of Maximum Upward Motion (m/sec), Maximum
Downward Motion (m/sec), and Maximum Rainwater Mixing
Ratio for the Model Storm 81
32. The Motion Field Within the Model Storm as Represented by
the Streamfunction (kg/m-sec) 82
33. The Pollutant Distribution at Four Different Times Following
its Insertion into the Storm Environment; (Upper left) Time = 0,
(Upper right) Time = 30 min, (Lower left) Time = 50 min, and
(Lower right) Time = 70 min 84
vi.
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TABLES
Page
1. Convective Storm Properties 9
2. Input Measurements from Field Study 29
3. Analytical Procedures for Rain Chemistry 34
4. General Field Information: August 1972 38
5. Results of Chemical Analyses 39
6. Condensation Nuclei: August 16 Aircraft Sounding .... 61
7. Sampling Line Average Concentrations: August 1972 .... 65
8. Selected Air Concentrations of Particulate Pollutants for
Midwest Cities, and Estimate of Maximum Dry Deposition
Flux for v, = 5 cm/sec 68
9. Scavenging Rates: August 1972 75
10. Fractional Removal and Rate of Removal by Scavenging:
Run 4, Lines B and C 76
11. Variables of State and Water Vapor Mixing Ratio as a
Function of Height Used as Environmental Conditions for
Model Calculations. Based Upon Observations Taken at
Lambert Field, St. Louis, Missouri on 21 August 1972
at 1417 CST 80
vii.
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ACKNOWLEDGMENTS
This research was conducted by scientific and technical personnel of the
Atmospheric Sciences Department of Battelle-Northwest Laboratories under
related services agreement BNW-389 with the Richland Operations Office,
Atomic Energy Commission, for the Division of Meteorology, U. S. Envi-
ronmental Protection Agency. The following Battelle personnel contributed
significantly to this project:
A. J. Alkezweeny F. B. Steele
J. M. Baily T. M. Tanner
F. 0. Gladfelder C. W. Thomas
D. W. Glover N. A. Wogman
M. C. Miller J. A. Young
J. W. Sloot
Our efforts formed a part of a cooperative effort, the Metropolitan
Meteorological Experiment (METROMEX). Other groups in this effort
included:
Illinois State Water Survey
University of Chicago
University of Wyoming
Stanford Research Institute
Argonne National Laboratory.
We express our sincere appreciation to these groups for their assistance to
this study.
We are also indebted to Mr. George Brancato and his staff at the National
Weather Service Station at Lambert Field, for their cooperation and tech-
nical interest, which were major factors contributing to the success of
this research. In addition, we express our thanks to Mr. Ralph Murkin
and the staff at the Lambert Federal Aviation Administration Control
Tower for their continued help and cooperation, which were also major
elements leading to the successful outcome of this project.
viii.
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SECTION I.
CONCLUSIONS
The concentration measurements of this study have demonstrated that pre-
cipitation scavenging by convective storms can be an extremely effective
mechanism for removal of urban pollutants from the atmosphere. Grid-
point measurements indicate that spatial concentration distributions of
common inorganic pollutants in their higher oxidation states—sulfate and
nitrate—show little variability over the scale of a kilometer or more.
Substances in lower oxidation states (with the exception of ammonia) tend
to exhibit more variability—ostensibly because of greater source-config-
uration dependence for these constituents.
The data from this study do not provide a simple or obvious assessment of
the relative contributions to precipitation chemistry of St. Louis vs.
"background" contamination. However, concentration—and subsequently,
scavenging rate—measurements made at various distances downstorm of the
urban area indicate that precipitation scavenging removal rates can be
comparable to urban emission rate estimates. The importance of background
pollution to this effect, as well as more quantitative explanations of
scavenging rates and source magnitudes will be examined in forthcoming
modeling efforts of this program.
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SECTION II.
RECOMMENDATIONS
This report documents results from two field studies, conducted during the
summers of 1972 and 1973. The recommendations following the first of these
two studies have been largely fulfilled by the second; we list them here
only to provide the reader some perspective to the program:
In view of our 1972 findings regarding spatial distributions
of rainborne pollution, an additional field program should be
conducted to expand the data base for the convective-storm
component of this study.
This additional program should have a modified sampler orien-
tation possessing the following characteristics:
a) A relaxation of sampler spacing in the cross-storm
direction
b) A grid orientation, rather than arcs, so that greater
down-storm resolution can be obtained
c) More samplers closer to the metropolitan core, and
d) At least one sequential precipitation sampler.
Field results from the 1973 experiments, which fulfilled these objectives,
are summarized in Appendix I of this report.
Additional recommendations arising from these two field investigations are
given as follows: First, a frontal-storm scavenging experiment should be
conducted in the St. Louis area to provide a RAPS data base similar to that
acquired for convective storms. Second, the data that have been collected
to date should be evaluated carefully, and examined in the context of the
models described in this report. Subsequently these (and possibly addi-
tional) models should be evaluated as potential candidates for incorpora-
tion in the RAPS model structure. A large fraction of the future program
support should be dedicated to this portion of the study to ensure the most
beneficial and meaningful utilization of these field results.
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SECTION III.
INTRODUCTION
The Regional Air Pollution Study (RAPS) has been initiated by the Envi-
ronmental Protection Agency with the primary objective of developing
comprehensive air quality models for use in support of future emission
control strategy. Because of the magnitude and complexity of this model-
ing problem, the RAPS has been designed to facilitate relatively independ-
ent modeling of individual mechanisms of atmospheric response; subsequent
combination of these interacting "submodels" will result in the desired
comprehensive models as shown by the simplified schematic of Figure 1.
Precipitation scavenging is one such submodel within this structure; the
objective of the research described in this report series is to formulate
reliable precipitation scavenging submodels in accordance with the overall
requirements of the Regional Air Pollution Study.
Precipitation scavenging is an important component of atmospheric response
both from the standpoint of delivery of pollutants to the Earth's surface
and from that of depletion of these materials from the atmosphere. In
modeling local phenomena, the traditional approach has been to neglect
the effects of scavenging, noting in the process that the small amounts of
depletion involved tend to add a degree of conservatism to calculations of
ambient air concentrations. On the scale of the present study, however,
scavenging processes tend, on the average, to reduce ambient levels sig-
nificantly. Here both the spatial and temporal scales are sufficiently
large that 1) slower removal processes tend to become significant, and/or
2) complex, efficient scavenging entities such as thunderstorms can com-
pletely run their course within the region of study. Thus, it is essential
that scavenging phenomena be considered in any comprehensive control strat-
egy that is regional in extent.
The formulation of adequate models to describe precipitation scavenging in
a regional situation necessarily involves consideration of a host of
pertinent atmospheric processes and variables. These include source
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characteristics and the efficiencies of removal associated with precipi-
tation of various types, whether through simple below-cloud scavenging
from pollution-laden air near the ground (washout) or through the more
complex process of uptake by storms and subsequent removal - possibly at
some place outside the metropolitan area. Precipitation chemistry, pre-
cipitation and cloud microphysics, and storm dynamics are all prime fac-
tors of consideration. Because of these multiple considerations this pro-
gram has been organized into individual segments, and a series of reports
will be published as the research progresses. The initial research em-
phasis is on the analysis of scavenging by convective storms; later
efforts will focus on frontal-storm activity. Accordingly, the objectives
of this initial report of the series are as follows:
1) examination of techniques for modeling of scavenging by
convective storms and their applicability to RAPS requirements,
2) discussion of field experiment design for convective-storm
scavenging as it relates to modeling demands
3) presentation of field data from the 1972 and 1973 convective-
storm field measurement series, and
4) presentation of a review of precipitation chemistry as it relates
to regional modeling requirements.*
Owing to unanticipated program changes, the 1973 field data are not
presented in detail. These are summarized in Appendix A, along with the
review of precipitation chemistry which has been included to provide an
overview of the current state of the art in this field. The remainder of
the above items are presented in the main text of this report.
The St. Louis, Missouri metropolitan area has been chosen as the site of
the RAPS field program. This is also the site of the Metropolitan Meteor-
ological Experiment (METROMEX), currently in its fourth year of progress.
METROMEX is a cooperative effort of independent research groups working in
the St. Louis area to examine urban weather modification effects. While
the research described in this report is aimed specifically at RAPS
*
This portion of the research effort was supported in part by funding
from the AEG Division of Biomedical and Environmental Research.
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objectives it is also an interactive component of METROMEX, and many of
the supporting measurements utilized in this report have been acquired
through cooperative efforts with our colleagues in the METROMEX program.
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SECTION IV.
MODELING OF SCAVENGING BY CONVECTIVE STORMS
There are several possible approaches to modeling scavenging by convective
storms, and consideration of these is a fundamental prerequisite for field
experiment design. We address this problem in the present section by first
considering the basic characteristics of convective storms, and then des-
cribing possible modeling formulations in the context of their implications
with regard to experiment design.
A QUALITATIVE CONVECTIVE STORM PICTURE
Qualitative descriptions of convective storm processes have been presented
in the meteorological literature at various times since the latter part of
the 19th century. Modifications have come about as more pertinent obser-
vations have been gathered, and as refinements in theory concerning cloud
dynamics and microphysics have developed which are consistent with these
observations. This description will be limited to the case of storms
experiencing moderate to strong vertical wind shear in convectively un-
stable environments, since the best organized storms in the St. Louis area
occur under these conditions during the summer months.
The typical dimensions of a thunderstorm (cumulonimbus cloud) are 5 to 30
km in horizontal extent and 10-18 km in the vertical, as shown schematic-
ally in Figure 2. Since the freezing level in summertime is usually at
the 4 to 5 km level, half or more of the cloud volume consists of ice in
various forms. Near the top the water is entirely frozen and an anvil-
shaped ice cloud may extend outward from the main portion of the storm
for many tens of kilometers in the direction of the strong upper level
winds. Near the cloud base, where in one area droplets form in upward
moving air and in another area rain falls in downward moving air, the
water (except for hailstones) is in the liquid state. Near the freezing
level a mixture of liquid droplets, snow, and hail may exist. At increas-
ingly higher levels in the cloud a lesser fraction of the water is in a
liquid or supercooled state.
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Table 1 includes estimates of the maximum warming in the updraft (result-
ing from the release of latent heat of condensation) and other quantities
for both the typical thunderstorm and the large severe storms.
Table 1. CONVECTIVE STORM PROPERTIES
Feature
Maximum warming in updraft
Maximum cooling in downdraft (surface)
Maximum updraft speed
Maximum water concentration
Maximum surface wind gusts
Average Storm
Few C
5-10 C
10-15 m/sec
5 g/m3
10-20 m/sec
Severe Storm
10-15 C
10-15 C
20-40 m/sec
10-15 g/m3
20-40 m/sec
The relationship of the motion of these storms to the motion of the envi-
ronmental air is not often a simple one. Since these storms tend to
exist in regions where both the speed and direction of the horizontal wind
vary with altitude, the speed and direction of the storm are not likely to
be the same as the environmental wind speed and direction at a given
altitude. The storms of weak to moderate intensity tend to move at speeds
and directions which are approximately the average of the environmental
winds through the height of the storm. With the larger, more intense
storms, however, the movement is partly translational and partly propa-
gative, and the motion is usually to the right of the mean environmental
wind direction and the speed somewhat less. This propagation is due to
either a continuous or discontinuous regeneration on the storm's right
flank which is closely related to the availability of moisture there.
The reason for the importance of vertical wind shear in combination with
2
convective instability was pointed out by Newton and is shown schemati-
cally in Figure 3. The arrows in the drawing represent the motion of the
storm itself and air motions in its environment; the lengths of the arrows
indicate relative magnitudes of storm or wind speed. It should be noted
that this is a two-dimensional representation in the plane of propagation
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of the storm, whereas real storms are three-dimensional. This considera-
tion, however, does not affect the basic concept to be put forth here.
Note that the storm motion is different from that in both low and middle
levels as well as high levels, so that new air is entering the storm at
various locations. Low level air enters from the right (downshear), but
because of the strong vertical shear, middle-level air overtakes the storm
from the left (upshear). The low-level air is quite moist, a situation
that favors updraft development due to buoyancy produced by condensational
warming; the middle level air is quite dry and favorable for downdraft
development by means of negative buoyancy produced by cooling, accompany-
ing the evaporation of liquid water. These are the basic driving mech-
anisms for the conversion of the latent energy of the environment into
the kinetic energy of the storm circulation.
There is also a cooperative interaction which occurs between the updraft
and downdraft within the storm. Details of this interaction are uncertain,
but basic mechanism can be inferred from observations in the storm's peri-
phery. Figure 4 illustrates this interaction, at least in part. The
evaporative cooling in the downdraft air produces a "dome" of cold air near
the ground which may be 10 C or more colder than the surrounding surface
air. This results in a hydrostatically-produced high pressure area in the
cold air which is one of three factors tending to accelerate low-level air
horizontally in the downshear direction. A second factor is that the air
which moves downward in the downdraft must spread horizontally as it nears
the ground. A third factor which also may be important in producing strong
horizontal motions along the right side of this cold air is the tendency
for the transfer of horizontal momentum from middle levels to lower levels
by the downdraft. These strong horizontal motions resulting from the
presence of the storm encounter the low-level ambient air, producing hori-
zontal convergence near the ground and upward motion at higher levels.
The moist ambient air is thus lifted over the cold advancing air to the
condensation level, where the release of latent heat allows for further
upward penetration of the cloud. The updraft is quite likely tilted from
the vertical in an upshear sense from the surface to the mid-troposphere
11
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so that rain produced in it falls into the downdraft region where it may
undergo varying degrees of evaporation. It is in this sense that the
updraft and downdraft are dependent one upon the other as was mentioned
previously.
With the preceding description in mind, a framework is available for the
discussion of convective storm scavenging models and the relation of each
to RAPS objectives. Although it seems likely in light of this description
that in-cloud scavenging as a result of incorporation of low-level polluted
air by the updraft is the dominating scavenging process, not all scaveng-
ing models attempt to treat this process explicitly. Therefore in the
following section in our discussion of various scavenging models, the
above concepts of storm structure are taken into account to varying degrees,
depending upon the spatial scale and detail contained within each model.
SCAVENGING MODELS
In reviewing potential modeling techniques for precipitation scavenging
prediction and assessment, it is important to note that despite large
differences in complexity, resolution, and scale, all such models are
formulated from basic material balances; thus it is convenient to cate-
gorize models in terms of this common property. Here we itemize and
describe briefly some potentially useful modeling approaches in order of
increasing complexity. One should note that the approaches described here
are certainly not the only ones possible. They do, however, provide a
summary of past and anticipated modeling activity that is adequate to
illustrate the present discussion of experiment design features.
Empirical-Climatological Approach^
As its name implies, this approach to scavenging analysis entails simply
the interpretation of wet deposition rates purely on the basis of past
behavior. It can be challenged in the present context because it is a
model only in the most general sense. It can be described in terms of a
gross material balance, however, and related to competing processes in the
atmosphere by defining the metropolitan area as a "system" and summing
13
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input and output contributions as indicated later in Figure 8. This gross
material balance concept is also useful for experiment design, since the
measurements that are pertinent to it tend also to fulfill the require-
ments of other modeling approaches. This balance will be discussed in
further detail in the following section.
Insofar as the prediction of specific concentrations of trace pollutants in
precipitation is concerned, the empirical-climatological approach is cer-
tainly the simplest, since it involves estimation solely on the basis of
past observations. It is also the easiest to interface with the other
RAPS submodels, since it requires minimal exchange of information between
components of the overall modeling structure.
Washout Ratios
Washout ratio is defined here as the ratio of concentrations of pollutant
A in water and in air at ground level:
_ mass of A in precipitation/liter precipitation ,-, s
w mass of A in air/liter air
3 4
Engelmann ' has formulated a simple model to explain the past observa-
tions of rather constant washout ratios for a number of substances over
wide ranges of conditions. As shown in Figure 5, Engelmann's approach is
to perform a macroscopic material balance over a storm or cloud that is
assumed to exist in a quasisteady state. Moist, polluted air enters the
system from the left, and its water vapor partially condenses. Consequent-
ly, a fraction of A is removed from the air and leaves via precipitation
scavenging; the remaining fraction leaves in the air exiting the system to
the right.
If m^, rcif, and m are the quantities of material entering and leaving the
system per unit time, then the material balance is given by
mr = mi " mf• (2)
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By making further simplifications—notably:
1) airborne A is well mixed in the horizontal and vertical,
2) the areas of the storm updraft and rain regions are comparable—
Engelmann used Equation (2) to formulate an expression for r . This is
w
,. - c - pf + U-n)p3 , HA
L ~ "" _ "T " T ~
w
where p = density of water
q = absolute humidity of air entering from left
f = fraction of particles which nucleate cloud droplets and
are subsequently removed
E = efficiency of cloud in removing water from air entering
at left
3 = dimensionless "reactivity factor"
H = cloud base height
A = below-cloud scavenging coefficient
J = rain rate.
The use of washout ratios for the RAPS is attractive because here again we
require little interchange of information between modules of the overall
urban model; in its simplest application one needs only the ground-level
concentrations in air to proceed. This model, however, is rather dissat-
isfying for application at St. Louis for a number of reasons. The two
most important of these are:
1) its quasisteady state basis is doubtful in view of the large
transient effects typical of convective storms, and
2) inhomogeneities in the concentration fields near St. Louis are
pronounced, in contrast to Engelmann's stipulation of well
mixed conditions.
Despite these obvious difficulties, the washout ratio concept may find
appreciable use in St. Louis on an empirical basis. Inhomogeneous concen-
tration fields, for instance, possibly may be "averaged out" by employing
long duration (e.g., 24-hr) air sampling techniques. This approach will be
investigated extensively in forthcoming reports.
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Washout Coefficients
In its strictest sense the washout coefficient is simply a transport
property. Its concept has been applied so extensively, however, that
it often has been tacitly redefined in the context of various models,
and at the present time a rather confused state of affairs exists. The
true washout coefficient is defined here in terms of a unit volume element
in the atmosphere. If k. is the rate of material A being removed from the
gas phase by hydrometeors within this element, then the washout coeffic-
ient is defined as
k
A =f , W
XA
where XA is the local gas-phase concentration of A.
A
This definition can be used to formulate relationships predicting gross
removal rates from the air and delivery to the surface. It is important
to note, however, that all suah relationships necessitate the use of some
type of idealisation., or "model" of physical behavior. An example of this
is an approach that has been used frequently in the past. This is to re-
late the flux of A to the ground in rainwater to a vertical integ-
ral of airborne concentration, thus
Such an expression, however, is based on the rather severe restriction of
vertical rainfall, as well as a number of additional assumptions. The
past tendency to redefine the washout coefficient according to Equation 5,
that is,
\-l
A = w.( \ vv(z)dzj t (6)
therefore should be regarded with the utmost caution.
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A more well-known example of simple modeling using the washout coefficient
is May's method of field analysis. Shown schematically in Figure 6, this
method visualizes a plume being emitted from a (point or area) source.
The system is assumed to be in a steady state in Eulerian coordinates. It
is most conveniently described in a Lagrangian frame of reference, however,
by considering a discrete, transient "puff" of the plume as it drifts in
the downwind direction. Performing a material balance over this puff of
initial mass m ,, one obtains
oA'
dm
where m. is the mass of A at a distance x downwind, and u is the mean
A
windspeed. Equating the amount removed from the puff to the amount de-
posited on the ground gives
dx
/+00
WA
.« A
dy , (8)
where b is the width of the sampling line in the x direction. Combining
Equations (7) and (8), and dropping the exponential term, the expression
A= — f\
moA/ *
V —00
results. This formulation has been used extensively for calculation of A
from field measurements; in
variant of this expression,
from field measurements; in fact, we have employed the continuous-source
A - W
where Q . is the pollutant release rate (moles/sec) and W is the scavenging
OA.
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rate (defined in Section V) (moles/cm sec), for numerous below-cloud scav-
enging applications.
The development of the above equations is contingent upon a host of model-
ing assumptions. These include (but are not restricted to) the assumptions
of
1) vertical rainfall
2) steady state (Eulerian)
3) non-meandering plume, and
4) no competing removal processes.
In view of this obvious contingency on modeling, one should avoid any tend-
ency to use the above equations to define the washout coefficient. This
statement applies equally to "rule-of-thumb" definitions—for example,
"the washout coefficient is the fractional removal rate." Such statements
are unavoidably contingent on modeling assumptions, and a clear distinction
between definition and approximation should be preserved in order to avoid
confusion in subsequent applications.
Macroscopic Storm-Cell Model
In addition to obvious divergences between the modeling assumptions listed
above and anticipated convective storm scavenging behavior, additional
problems arise which concern the two following features:
1) The propagation of convective cells is not generally in the
same direction as the ambient wind, and
2) The dimensions of the cells are generally smaller than those
of the urban plume.
In an attempt to remedy these shortcomings, we have formulated an addition-
al macroscopic model by performing a material balance over a storm as it
transects the urban plume as shown in Figure 7. Details of this model will
be given in a forthcoming report. Basically it assumes a quasisteady state
storm passing through a varying concentration field. Transients in actual
storm characteristics can be incorporated, if desired, by discretizing the
quasisteady state system in finite increments along the storm path. Re-
quired input to this model—assuming the storm characteristics are known—
is simply the environmental air concentration.
20
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H
M
P-l
21
-------
Microscopic Formulations Describing Scavenging Behavior
Thus far we have concerned ourselves with gross material balances over
macroscopic systems. A more refined approach is to formulate and solve
the microscopic equations of conservation for pollutant in the precipita-
tion and in the air. In their most general form these are
9P
and 3p
A1
T = ~V'PA1VA1 + kA + rAl (PreclPitation phase) (11)
~ kA + rA (gas phase)
Here p - and p denote molar densities* of liquid- and gas-phase pollutant
A (moles per unit volume of total space) respectively. Similarly v and
/LJ.
v. denote average velocity vectors for pollutant in the rain and in the
Ag
gas phase, and r - and r are the corresponding terms for generation of
AX Ag
pollutant by chemical reaction, k is defined again as the time rate of
loss of pollutant mass in the gas phase by washout, per unit volume of
space.
Equations (11) and (12) are coupled to a mathematical description of storm
behavior through the velocity vectors v... and v . Such a description can
be provided by storm models obtained by formulating and solving further
conservation equations (total mass, water mass, momentum and energy). At
the present time such models are capable of calculating the time evolution
of air motions, temperature, water vapor, and liquid water distributions in
either one, two, or three space dimensions. The one- dimensional models
generally concentrate on the details of the cloud microphysics and employ
assumptions concerning the dynamics. The two- and three-dimensional models,
on the other hand, attempt to deal with the dynamics more realistically
while employing parameterization schemes to deal with the microphysics of
clouds and rain. In the future with the coming of larger and faster
* Here it should be noted that pAi denotes a density of liquid-phase A
(moles per unit volume of space) corresponding to an average of the rain-
drop ensemble.
22
-------
computers, detailed microphysics will be included in three-dimensional
models and the realism of these numerical experiments will be increased.
Because of the coupling mentioned previously, precipitation scavenging is
intimately related to cloud microphysics, and incorporation of Equations
(11) and (12) in conjunction with storm models of this type must obviously
involve a number of simplifying assumptions. Inclusion of scavenging
features in convective cloud models at the present time must be either
(a) in detailed form in one-dimensional models or (b) in parameterized
form as is the microphysics in two- or three-dimensional models. The
relative merits of these approaches depend to some extent upon the type
of convective cloud with which one wishes to deal. A small shower cloud
existing in an environment whose motion is characterized by very little
wind shear might be dealt with fairly realistically in a one-dimensional
model. A large isolated thunderstorm on the other hand would probably
require a three-dimensional treatment. A possible exception is the well-
organized deep convection which occurs in lines which propagate over the
earth in a direction roughly perpendicular to the line orientation. The
basic aspects of this type convection can be treated rather successfully
Q
in two dimensions.
The additional detail of the microscopic approaches necessitates a consid-
erable increase in information to be exchanged between modules within the
RAPS scheme. Further aspects of this problem will be discussed in a later
section of this report, where initial applications of a two-dimensional
storm model to analysis of scavenging by a St. Louis convective storm
are presented.
23
-------
SECTION V.
EXPERIMENT DESIGN
In view of the complexities of convective storms, and the input require-
ments of models such as those discussed in the previous section, it is
convenient to idealize our visualization of the storm somewhat in order
to formulate a basis for experiment design. In modeling we are basically
interested in material balances of pollution as it is exchanged between
the atmosphere, precipitation and the ground surface. Such balances tend
to become increasingly complex as finer detail is included regarding
spatial and temporal variations; accordingly, the simplest possible such
approach is to formulate a macroscopic material balance over the metro-
politan complex, as was set forth in Section IV.
This formulation may be accomplished by summing contributions from various
pollution sources and sinks as shown in Figure 8. The balance for each
pollutant of interest can be stated as follows:
Time rate of change of mass of material
in the system =
Rate of emission to the atmosphere within
system +
Rate of transport to the system by flow -
Rate of transport from the system by
flow + (13)
Rate of gain of material in system by
chemical and microphysical reaction
Rate of loss of material from system
by dry deposition
Rate of loss of material from system
by precipitation scavenging
Mathematically, this corresponds to the equation
25
-------
-\--l-
00
§
26
-------
Ay f Ax
-/
o
/•Az /»
0 * 0
Ax Ay Az AA
3t / I xoA
0 0
•Az
9x 3y
Az/»Ay
/•Az/»
0 0
X, v. 9y 3z
AA Ax J
*AVAx
+/7
Jo Jo
XA VAy 3x 9z
x = 0
•Az /»Ax
•n
x = Ax
o o
Ay/» Ax
a
• Az-Ay »L
•o * o *o
/•Ay /» Ax
*AVAZ
Ay/* Ax
•n.
z = 0
o o
r. (x,y,z) 3x 3y 3z -
A
(x,y) 3x 3y -
/Ay /» Ax
. "
3x
VAZ 8x 3y
= 0
y = Ay
z = Az
(x,y) 3x 3y .
(14)
o o
where
X. = air concentration of pollutant A (mass /volume)
A
Q = emission rate of A (mass /area -time)
•TT
Ai = velocity of A in gas phase in ith direction
r = generation rate of A by reaction (mass /volume* time)
A
d = dry deposition flux of A (mass/area- time)
w = scavenging flux of A (mass /area* time) , and
Ax,Ay,Az = dimensions of systems.
Equation (14) actually corresponds to the basis for a comprehensive RAPS
model as depicted in Figure 1; the primary concern of this research pro-
ject is restricted to the elucidation of w , the precipitation scavenging
A
flux. Because of w 's dependence on other features of the total material
27
-------
balance, however, each of these entities must be considered—both from the
standpoint of formulating a meaningful experiment design and from that of
ensuring that the submodels developed will be of maximum use as modules in
an interactive system.
Proceeding with the macroscopic material balance approach, it is obvious
that no reasonable field experiment can be designed which could accurately
"close" the material balance of Equation (14). Accordingly, we have empha-
sized direct measurement of scavenging fluxes in this program through use
of a precipitation sampling array, but also have included limited support
operations which, in conjunction with data obtained from other sources,
allow approximate material-balance information to be obtained for scaveng-
ing analysis. Table 2 provides a summary of these sources of information.
In addition to the variety of simplifying assumptions and approximations
necessitated by this approach, some idealization of storm characteristics
is also desirable. The preferred storm for study, for example, would be a
single-cell convective disturbance which traverses the city and sampling
lines on both sides of town without substantial changes in the storm's
character. Such behavior would allow a rather direct comparison of pre-
and post-city washout rates, and would simplify other aspects of the mater-
iable balance considerably. It is obvious that actual storms rarely
exhibit such behavior, but experimental data derived from a number of
storms will be useful in assessing the variabilities in scavenging behavior
as the storms deviate from the ideal in different respects.
The precipitation sampling array for the 1972 field series is shown in
Figure 9. The washout flux w was determined at each sampling station via
chemical analysis of the collected rainwater. The spatial array of the
samplers then dictated the extent to which the total rate of scavenging
removal—the last term on the right of Equation (14)—could be evaluated.
Resource and personnel limitations did not allow an extensive gridwork in
both the x and y directions, so we opted to evaluate the integral in the
y direction, normal to the expected direction of storm movement. Thus the
array took the form of lines of samplers, and the cross-plume integrated
flux, which we shall refer to subsequently as the scavenging rate, is
28
-------
Table 2. INPUT MEASUREMENTS FROM FIELD STUDY.
Material Balance
Component or
Meteorological Parameter
Source of Information
"Ai
Storm characteristics
& trajectory
Rainfall pattern
Temperature, R. H.
St. Louis Air Pollution Control
District Network
Illinois EPA network
CAMP station
Limited aircraft sampling
(Battelle & ISWS)
Balloon soundings (Battelle & others)
Emissions Inventory (EPA)
Estimation and dustfall measurements
NWS radar (Lambert field)
ISWS radar (Pere Marquette)
METROMEX flights
Battelle precipitation chemistry
array
ISWS raingauge network
Balloon soundings (Battelle & others)
Aircraft data
Virtually no direct input. Some indi-
rect estimations possible by observa-
tions of concentration ratios in rain
and in air. Note literature survey
in Appendix II.
Comprehensive precipitation chemistry
array—major measurement emphasis of
this study.
29
-------
CN
r^
Oi
.H
H
W
S3
C3
O
H
fe
30
-------
/b n-1
w (x,y) 3y c* l/2£ (c J. + c , , J ) |y - y | (15)
^^ ri 1 Lll~!~j_,J l~r_l_ 1 1TJ.
T=1
n-1
z
i=l
where n = the total number of collectors along the line
c . = the concentration mass of pollutant at the ith collector
along the line, moles/I
J. = rainfall rate at ith collector, cm/sec
y. = the coordinate of the ith collector, cm.
The expected motion of storms was generally from northwest to southeast,
so one line was placed upstorm (Line A—numbers 147-200), and two lines
were placed downstorm (Line B—numbers 1-38—and Line C—numbers 49-97).
The upstorm line was included for measurement of background fluxes.
A proper evaluation of W requires that the sampling line contain the
y-direction "extent" of the scavenging. There can be two interpretations
of this extent, depending on the type of storm encountered. If the storm
is smaller than the breadth of the city, the containment must be of the
rainfall (the pollution source is then presumably only part of the city).
In the case of more widespread rain, the containment must be of the down-
storm projection of the city. These considerations required that the
sampling lines be at least as long as the width of the city, but also that
the spacing be fine enough so that there be proper scavenging resolution
of smaller showers. A compromise was reached whereby the sampler spacing
was set at about 1 km (on the assumption that significant showers would be
at least kilometers wide) on the inner lines, and about 2 km on the outer
line. Since only one field worker was assigned to each line, the complete
line (containing more than the y-direction projection of the city) could
not be set out on short notice. Consequently we deployed samplers only
over selected segments of the lines, and relied on storm forecasting to
select which portions of the lines to deploy. During the latter portion
of the experiment series, we doubled the sampling spacing, as it appeared
that most rains would be extensive.
31
-------
A special precipitation collector was required for this study because of
the desire for chemical analysis of a number of pollutants. Furthermore,
the pollutants varied widely in chemical state, reactivity, and sensitiv-
ity to post-collection conditions. In the past we have chemically fixed
the pollutants at the time of collection, but this required separate
collectors for each pollutant and its particular fixing agent. This has
been fraught with technical difficulties, and in the present study we
attempted to fix the pollutants on collection in single samplers using a
freezing technique. It is well known that extremely small amounts of
pollutants tend to deposit on the walls of rain collectors unless they are
fixed in the ice structure. To a degree this was important in the present
study, but we were dealing mainly with larger concentrations. Our main
concern was with chemical deterioration, such as conversion of NOo" to
N03~ or desorption of S02 or the ammonium ion in the form of NH3.
A sampler was designed which would freeze rainfall as it was collected,
and which would remain effective in the field for several hours after
deployment. The sampler, shown in Figure 10, consists of a 500 ml plastic
bottle attached to a 20 cm diameter funnel. In operation this arrangement
was enclosed in a Styrofoam insulating container with about 1 kg of dry
ice. Thus with deployment of only one sampler and subsequent recovery of
one rain sample at each position, we could analyze for all the desired
pollutants. Bottle capacity corresponded to about 2 cm of rainfall; in the
few cases of rainfall exceeding this amount, estimates were made of amounts
up to an additional 2 cm from observation of the level of water in the
funnel.
Rain samples were kept frozen until just before chemical analysis, which
was completed generally within a few days at the Battelle mobile air pol-
lution laboratory, located at Glen Carbon, Illinois. Some of the samples
from the later runs were packed in dry ice and flown to Richland, Washington
for analysis after the conclusion of the field trip.
The chemical constituents of the samples which were determined were: pH,
S02, SOA=, N02~, NC>3~, and NH^+. The first was determined through standard
pH technique, the rest by wet chemical methods, using Technicon Autoanal-
ysers.
32
-------
RAIN COLLECTOR FUNNEL
STYROFOAM
500 ML BOTTLE
DRY ICE
FIGURE 10. FREEZING PRECIPITATION SAMPLER.
33
-------
A summary of the species examined and the analytical methods used is given
in Table 3.
Table 3. ANALYTICAL PROCEDURES FOR RAIN CHEMISTRY.
Species
H+ (PH)
S02 (dissolved)
SO =
•r
NO -
•J
NH.+
/i
'"T
N02"
Analytical Procedure
Glass electrode
Q
Modified West & Gaeke method
Methylthymol blue method
10
Phenoldisulf onic acid method
11, 12
Chromotropic acid method
Phenoldisulfonic acid method
13
Saltzmann method
The samples which were returned to Richland, Washington, were subjected to
repeat nitrogen pollutant analyses, both as a check on initial procedures
and as a limited evaluation of potential post-collection changes. In addi-
tion, an independent method of nitrate analysis was performed as a check on
the nitrate procedure. The results of these reanalyses and discussion of
errors appears in Section VII.
The general process of conducting scavenging runs was as follows. The field
director, stationed at the National Weather Service radar station at Lambert
Field, assessed the run potentials for each day and coordinated all activi-
ties. When the early morning forecast called for potential showers, the
field workers were alerted; if rain appeared imminent, they were advised to
prepare the samplers with dry ice, and, if the likely motion and extent of
rain were reasonably certain, set out over a directed portion of the sampl-
ing lines. The radar observations were necessary for forecasting, it turned
out, because it was generally impossible to tell by visual observation from
the east side of the city whether or not a shower was coming until the onset
of lightning, or obscuration of sunlight. This was because of the poor
34
-------
visibility attributable to the general high pollution level over the city
during the experiment period. After set out of the samplers and evidence
that rain had fallen on the sampling lines, collection was instituted at
the discretion of the field workers, and the samples were put in frozen
storage.
35
-------
SECTION VI.
EXPERIMENTAL RESULTS: AUGUST, 1972
During the field experimental period—August 8-31, 1972—precipitation
was collected on five convective storm days. In addition, radiosondes
were flown—attempts were made on all storm days, but flights on other
days were also accomplished in support of METROMEX activities—and near-
continuous meteorological monitoring was maintained at the National
Weather Service station at Lambert Field. Table A is a summary of these
activities, and Table 5 is the complete list of precipitation sample
pollution concentrations. Further discussion of the concentrations is
centered in Section VII; the following is a summary of the meteorological
and sampling situations for the scavenging runs, plus a brief presentation
of aircraft results. All times mentioned are Central Standard, and "STL"
is the designation of the weather station at Lambert Field.
RUN 1 (August 12, 1972)
At 0600 a stationary front was located across the Great Lakes, northern
Illinois and central Iowa, with a short wave trough at 500 mb over eastern
Missouri and Illinois moving slowly eastward as it deepened. A line of
showers oriented east-west moved across the St. Louis area from north to
south as an apparent squall line. Thunder was reported at STL from
0937-1000, and light showers occurred until 1143. The total rainfall at
STL was only 0.05 cm, but radar estimates indicated cloud tops to 12 km
before and during passage of the line over the city. One cloud top was
noted to 14 km at 1040 some 75 km east-southeast of STL. A rather intense
cell passed over sample Line B between 0840 and 1040.
On this day, laboratory and sampling line setup was still underway, with
Line C not having been established. The early arrival of rainfall pre-
cluded setout of samplers on Line A, but the southern portion of Line B
was deployed beginning at 0900. Figure 11 is a map showing the precipi-
tation amounts which fell during the sampling time, and the locations of
37
-------
Table 4. GENERAL FIELD INFORMATION: AUGUST, 1972.
Date
8/12/72
8/17/72
8/19/72
8/20/72
8/21/72
8/25/72
8/28/72
Run
No.
1
2
3
4
5
Sample
Line
B
B
C
B
A
A
B
C
-A
Position
Numbers3
19-38
22-28
61-74
1-5
146-153
146-190
15-37
65-89
154-168
Indus iveb
Collection Time
(Time of Day-CST)
0912-1433
1421-1647
1334-1700
1349-1649
1530-1840
1530-2030
1455-1731
1503-2001
0955-1705
Approximate
Storm
Path
NW to SE
NW to SE
NE to SW
NE to SW
NE to SW
NW to SE
NW to SE
NW to SE
W to E
Rawinsonde
Release
Time (CST)
1026
1402
0938, 1430
1417
1025, 1501
1053
Sample positions used at which measureable rain fell.
Total time from first collector out to last collector in.
the active sampling positions. The rainfall data on this map and subse-
quent similar ones were those recorded on the Illinois State Water Survey
precipitation array, which consists of over 200 recording rain gages cover-
ing an area somwehat larger than our map area.
Radar observations of movement of peak echo intensity indicate that the
cell which affected Line B moved from about 320 degrees at about 30 km/hr.
The origin of the cell appeared to be roughly over the central business
district of St. Louis, with sampling positions 25-35 ostensibly most
affected by the city's plume. Figure 12 is an hour-by-hour illustration
of National Weather Service radar echo patterns during the time of Run 1
sampling.
38
-------
Table 5. RESULTS OF CHEMICAL ANALYSES
Date
8/12/72
8/19/72
8/20/72
Run
1
2
3
Position
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
22
23
24
25
26
27
28
1
2
3
4
5
61
62
63
64
65
66
67
68
69
70
71
72
Rainfall,
mm
3.42
2.09
1.49
3.18
1.45
.82
.88
.60
.63
.69
.62
.58
.68
.66
.72
1.26
2.06
.57
1.09
2.79
4.54
2.02
.26
.15
12.8
8.08
1.37
.06
.35
.23
.20
.86
.28
.06
.15
.18
.57
9.09
16.6
18.2
Concentration (g-moles/1) x 10
N02~
.063
.059
.056
.047
.243
.502
.028
.313
.046
.583
.039
.067
.074
.074
1.07
1.04
.086
.065
.022
.239
.087
.087
.087
.109
.783
.043
.065
.850
.021
.043
.043
N03
161
104
93.5
123
146
154
206
20.2
49.6
44.4
NH.+
4
18.1
24.7
27.2
14.9
21.7
6.78
6.78
9.06
12.6
13.8
17.3
30.9
16.8
46.3
40.6
23.4
21.7
44.4
55.6
99.4
49.6
31.2
22.7
H+
166
141
174
200
120
58.9
115
97.7
102
55.0
129
33.1
100
132
45.7
132
129
2.00
1.23
42.7
209
245
25.1
182
214
170
112
153
224
10.7
93.3
77.6
107
so -
4
44.0
47.1
60.9
47.1
46.0
60.1
31.3
20.8
26.7
26.4
28.3
56.7
47.1
46.7
37.8
35.8
29.3
183
261
143
108
136
183
183
133
164
219
173
230
297
257
109
163
286
149
29.1
35.6
25.4
39
-------
Table 5 (continued). RESULTS OF CHEMICAL ANALYSES
Date
8/20/72
8/21/72
Run
3
4
Position
73
74
146
147
148
149
150
151
152
153
15
17
18
19
21
23
25
27
29
31
33
35
37
65
67
69
71
73
75
77
79
81
83
85
87
89
146
148
150
152
154
156
158
160
Rainfal],3
nun
22.8
9.89
.03
1.3
6.5
11.0
9.8
11.3
6.2
3.4
1.4
1.6
9.8
14.0
10.0
5.4
27.0°
42.0°
59.0°
56. 0C
52.0°
49.0C
44.0C
1.6
1.3
1.4
3.1
4.7
11.5
12.7
15.8
22.0°
17. Oc
11.9
2.9
1.5
.7
.7
.7
.8
2.3
1.8
2.0
3.2
U £
Concentration (g-moles/1) x 10
N02~
.021
.021
.196
.065
.086
.130
.196
.086
.152
1.96
1.43
.174
.087
.065
.283
.043
.043
.021
.065
.043
.587
.870
.152
.086
.978
.086
.065
.021
.021
.021
.043
.021
.065
.043
.043
.043
.217
.043
.522
.543
.043
.043
.065
N03
49.4
89.8
229
132
123
169
157
123
157
130
130
77.6
97.7
31.2
99.5
52.7
43.2
43.8
36.1
50.6
79.5
92.8
109
93.9
71.5
67.5
48.8
37.2
34.9
33.8
35.7
47.0
54.2
42.0
49.8
43.5
35.5
NH4+
26.4
24.4
68.3
52.9
50.2
52.4
44.7
40.1
62.2
9.06
39.6
27.2
14.9
33.3
14.7
28.7
27.2
27.9
21.4
19.3
5.31
20.2
9.06
20.2
25.4
10.9
17.3
18.6
25.4
25.2
43.3
14.2
19.3
10.2
10.2
5.17
14.9
H+
135
191
95.5
282
178
70.8
251
158
229
21.4
38.0
38.9
126
191
9.55
138
115
93.3
112
72.4
5.75
12.6
77.6
61.7
0.95
162
11.2
69.2
60.3
40.7
46.8
44.7
75.9
132
91.2
58.8
15.8
60.3
40.7
56.2
115
158
83.2
so4=
53.5
91.1
233
186
126
261
144
117
167
158
147
130
21.6
99.8
103
89.6
143
69.0
50.7
51.4
48.5
175
93.4
99.2
133
127
77.0
42.5
32.5
16.5
27.8
34.9
41.5
32.9
63.8
56.8
53.1
47.7
30.1
51.1
65.2
52.4
40
-------
Table 5 (continued). RESULTS OF CHEMICAL ANALYSES
Date
8/21/72
8/25/72
Run
4
5
Position
163
165
167
169
171
173
175
176
178
180
182
184
185
186
188
190
154
156
158
160
163
165
167
168
RainfalJ,3
mm
4.6
1.4
2.0
3.1
1.8
0.6
0.15
0.4
0.06
.1
.15
5.4
10.6
3.45
2.4
1.1
.3
.3
.3
.3
.3
.7
.8
.8
Concentration (g-moles/1) x 10
N02~
.065
.065
.043
.043
.109
.761
.478
.283
.609
.898
.870
.283
.043
.065
.021
.152
.043
.021
N03
46.1
70.6
74.3
49.8
48.6
34.3
41.8
52.4
92.1
84.5
NH.+
4
22.7
17.7
37.4
16.6
32.2
13.3
12.3
22.2
32.2
23.7
H+
66.0
89.1
70.8
87.1
74.1
58.8
5.25
45.7
3.80
29.5
33.9
14.4
50.1
55.0
40.7
2.45
135
39.8
58.9
42.7
SV
39.4
67.3
70.4
47.6
73.4
115
120
32.5
26.7
53.3
60.5
60.0
114
94.6
62.1
79.7
42.3
28.1
31.3
32.0
Calculated from volume of water collected by sampler.
All S0_ concentrations were insignificant.
Estimated from Illinois State Water Survey raingage records.
41
-------
a
42
-------
AUGUST 12, 1972 1040 CST
AUGUST 12, 1972 1240 CST
ST. LOUIS ISTLI INDUSTRIAL AREA
WEATHER RADAR ECHOES: UNATTENUATED
WEATHER RADAR ECHOES: 36db ATTENUATION
SAMPLING ARCS
III
FIGURE 12. NATIONAL WEATHER SERVICE RADAR ECHO MAPS, RUN 1
43
-------
RUN 2 (AUGUST 19, 1972)
The surface weather pattern at 0600 again showed a stationary front north
of the area, with a large weak high pressure area over the entire eastern
United States. At 500 mb a broad ridge extended from the Gulf to central
Canada. No radar echoes appeared until about noon. The afternoon situa-
tion was typified by an apparently random cell development with most cells
in the area moving from about 290 degrees. A few persistent cells passed
both north and south of STL with thunder reported between 1348 and 1415.
No precipitation fell at STL, however, nor on the setout portion of Line A.
The radiosonde flight at 1402 indicated moderate moisture to 400 mb. The
temperature and wind profiles for this sounding are shown in Figure 13.
Inasmuch as most cells were building rapidly and rather shortlived, a
section of Line B approximately downstorm of the city was set out, begin-
ning about 1400. The downstorm personnel doubled up to expedite this
setout. Figures 14 and 15 indicate that the sampled cell matured to the
south and east of the deployed area; however, only seven of the rain col-
lectors had measurable amounts—those from a trailing edge of the shower.
Any rain that occurred on the positions south of Number 28 apparently fell
just prior to setout. Thus, the containment achieved was of a small side
shower trailing the main storm. The direction of movement of the cell was
approximately 305 degrees; thus the sampled rain would appear to be direct-
ly downstorm of the city. The origin of the cell is uncertain, as the cloud
buildups were rapid and randomly placed, and the time series of radar pho-
tographs contains some gaps. The speed of motion of the major echo was
about 35 km/hr.
RUN 3 (AUGUST 20, 1972)
The synoptic situation at 0600 was characterized by a wave centered in
North Dakota with a cold front extending southward to eastern Colorado and
a stationary front southeastward through Iowa and Illinois, and to Alabama.
The latter later provided "back door" frontal activity, touching off a line
of thunderstorms moving across the St. Louis area from northeast to south-
west. Radiosondes taken at STL at 0938 and 1430—Figures 16 and 17—
44
-------
WM BERT FIELD -ST. LOUIS
AUGUST 19, 1972 1402 CST
2002 Z
TEMPERATURE
WIND
DIRECTION-SPEED
(DEGREES -KNOTS)
290 14
SATURATION
ADIABAT
TEMPERATURE F
FIGURE 13. RADIOSONDE RESULTS, 1402 CST, AUGUST 19, 1972.
.0
E
O£.
00
Qi
Q.
800
900
1000
45
-------
w
c^
:=>
46
-------
AUGUST 19, 1972 1403 CST
AUGUST 19, 1972 1540 CST
ST. LOUIS ISTLI INDUSTRIAL AREA
WEATHER RADAR ECHOES: UNATTENUATED
WEATHER RADAR ECHOES: 36db ATTENUATION
SAMPLING ARCS
FIGURE 15. NATIONAL WEATHER SERVICE RADAR ECHO MAPS, RUN 2,
47
-------
LAM BERT FIELD -ST. LOUIS
AUGUST 20, 1972 0938 CST
1538 Z
TEMPERATURE
DIRECTION -SPEED
(DEGREES - KNOTS)
SATURATION
ADIABAT
ce
CO
CO
Di
Q.
1000
120
TEMPERATURE F
FIGURE 16. RADIOSONDE RESULTS, 0938 CST, AUGUST 20, 1972.
48
-------
LAMBERT FIELD -ST. LOUIS
AUGUST 20, 1972 1430 CST
2030 Z
TEMPERATURE
WIND
DIRECTION - SPEED
(DEGREES - KNOTS)
110
TEMPERATURE F
Qi
Q-
1000
120
FIGURE 17. RADIOSONDE RESULTS, 1430 CST, AUGUST 20, 1972.
49
-------
indicated a decrease in moisture at all levels in the interval with the
earlier sounding fairly moist, and both soundings conditionally unstable.
A few cells were observed on radar to the northeast at 0940, but they soon
dissipated. By 1240, a north-northwest/south-southeast line of cells had
formed about 55 km east of STL. Subsequent radar observations showed rapid
growth and merging of these cells as well as similar activity in an amor-
phous grouping 140 km west of the city. At 1540, the city was surrounded
by this activity with several cumulonimbus tops reaching 15 km. Movement
was minimal and disorganized, but in general the growth process brought
them nearer to STL from both east and west by 1540. At 1640 the two masses
had joined south of STL with a pattern of major cells in a rough east-west
line with no activity to the north. No precipitation fell at Lambert Field,
it being just north of the vertex of the converging cells.
A decision as to which portions of the sampling lines to outfit with col-
lectors was hindered by an uncertainty as to which direction of storm
movement would affect the St. Louis area. Finally, the northern portions
of (normally upstorm) Lines B and C, and the southern portion of Line A
were set out. Most of the rain at Line B fell north of the established
line, and no containment was achieved there. Cells also crossed A and C,
but the rain map, Figure 18, shows that the three line collections came
from three distinct showers.
The rain which fell on Lines B and C came from a north-south line of
activity that radar observations indicated moved very slowly if at all.
The northern cell, the most intense rain of which was north of Line A, was
moving about 5 km/hr from 90 degrees. The Line C cell probably did not
move at all, and developed and matured in place. Any possible movement of
this cell would have probably been 90 degrees also. The cell which affected
Line A was apparently part of the western edge of the "V" formation of
cells, and may represent an entirely different air mass. It moved from
350 degrees at about 13 km/hr, and probably originated some distance west
of the city. Thus all the Run 3 collected rain came from storms whose
origin and movement were not clearly related to the city's pollutant
source.
50
-------
51
-------
RUN 4 (AUGUST 21, 1972)
The early morning surface weather charts showed a cold front extending
from Lake Superior southwest to the Oklahoma panhandle. A squall line
some 185 km in advance of the front arced from south central Wisconsin to
the Kansas City area. Radiosondes were flown from the St. Louis Arch—on
the downtown waterfront—at 0625 and 1130 to 700 mb, and a 1417 sounding
at STL to 400 mb. The latter sounding is shown in Figure 19. All the
soundings were relatively dry except for a moist layer between 800 and 750
mb on the latter two.
At 1040 radar echoes indicated a northeast-southwest line of precipitating
cells 185 km northwest of STL with motion indicated from 290 degrees at
28 km/hr. At 1440 the largest area of echoes was west to southwest of STL
from 55 to 230 km. At 1500, a thunderstorm began at STL, and though cells
moved over the station for the next three hours, only a trace of precipi-
tation fell. The rainfall pattern, Figure 20, and the radar maps, Fig-
ure 21, indicate that most of the intense rain development occurred south
and southwest of STL. Radar plots showed strong cells rising to more than
12 km crossing the downstorm sampling lines until at least 1700. Activity
continued with less intensity until about 1900.
All three sampling lines were set out, this time at double spacing to con-
tain a greater extent of precipitation. Several small cells affected
Line A, while a large mass of storm cells crossed both downstorm lines.
Intense precipitation was experienced in the area; rainfall totalled 9.5
cm in downtown St. Louis, some 10 cm in Cahokia, Illinois, and over 7 cm
across Line B. Strong winds felled power lines and trees along Line B, and
2 cm diameter hail was unofficially reported at Cahokia.
An examination of the precipitation patterns indicates that two separate
showers affected Line A. The northern cell—which would have been an ideal
storm for our purposes, had it passed over St. Louis—was long-lived and
moved steadily from 260 degrees at about 25 km/hr, passing directly over
Alton, Illinois. Its origin was likely some distance west of the city.
The major activity which affected Lines B and C first appeared on radar
about 10 km east of STL at 1510, and moved at approximately 40 km/hr from
52
-------
LAMBERT FIELD-ST. LOUIS
AUGUST 21, 1972 1417 CST
2017 Z
TEMPERATURE
WIND
DIRECTION - SPEED
(DEGREES - KNOTS)
SATURATION
ADIABAT
30
70
80
TEMPERATURE °F
90
100
110
.0
E
700
800
900
000
120
FIGURE 19. RADIOSONDE RESULTS, 1417 CST, AUGUST 21, 1972.
53
-------
Pn
S5
M
O
CM
54
-------
AUGUST 21, 1972 1610 CST
AUGUST 21, 1972 1707 CST
ST. LOUIS [STL) INDUSTRIAL AREA
WEATHER RADAR ECHOES: UNATTENUATED
WEATHER RADAR ECHOES: 36db ATTENUATION
SAMPLING ARCS
FIGURE 21. NATIONAL WEATHER SERVICE RADAR ECHO MAP, RUN 4.
55
-------
320 degrees. After passing Line C, the mass of cells became more wester-
ly, and increased in speed.
RUN 5 (AUGUST 25, 1972)
At 0600, a low pressure center was located at the Missouri-Nebraska border,
a frontal wave with warm front extended to Springfield, Illinois, and a
cold front extended southward from the low center to just east of the
Kansas-Missouri border. Temperature profiles from radiosoundings flown
from STL are shown in Figures 22 and 23.
At 0930 a 75 km-long line of cells oriented north-south approached St. Louis
from 45 km to the southwest. The cloud tops were only about 7.5 km and
thunder was not reported at STL, though showers began at 1035 and persisted
about an hour. The line preserved its identity for two hours as it moved
eastward, but numerous holes in the line appeared after 1130. A second
group of cells northwest of STL at 1130 grew to form another north-south
line over 500 km in length, with St. Louis 35 km east of the center of the
line at 1430. This line also had gaps, however, and one group of cells
passed over the city at about 1530. This group dissipated before it reach-
ed the downstorm sampling lines; thus only Line A received significant
precipitation. Detailed analyses of Run 5 will not be presented here.
56
-------
LAMBERT FIELD -ST. LOUIS
AUGUST 25, 1972 1025 CST
1625 Z
TEMPERATURE
WIND
DIRECTION -SPEED
(DEGREES -KNOTS)
225 \36
SATURATION V
(/I
LU
C£
700
800
900
1000
70
80
TEMPERATURE °F
90
100
110
120
FIGURE 22. RADIOSONDE RESULTS, 1025 CST, AUGUST 25, 1972.
57
-------
LAMBERT FIELD-ST. LOUIS
AUGUST 25, 1972 1501 CST
2101 Z
TEMPERATURE
WIND
DIRECTION -SPEED
(DEGREES-KNOTS)
39 /
SATURATION
ADIABAT
400
80
90
100
110
FIGURE
TEMPERATURE °F
23. RADIOSONDE RESULTS, 1501 CST, AUGUST 25, 1972.
500
600
700
800
900
1000
120
58
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AIRCRAFT MEASUREMENTS
During the field-experiment period in August, 1972, several aircraft
flights collected pollutant air concentrations at upwind locations, over
the city, and at downwind locations at various levels in the lowest 1.5
km of the atmosphere. Though it was intended to gather this information
on storm days, specifically to provide estimates of pollutant emissions
for inclusion in Equation (14), scheduling difficulties allowed flights
only on other days, generally in fair-weather conditions. The results of
one such flight will be described here, however, to note the type and
capabilities of the instrumentation involved.
On August 16, 1972, an aircraft sounding was made on tracks flown roughly
perpendicular to the mean wind direction in the lowest 1.5 km. Instru-
mentation included a Sign-X S02 monitor and a condensation nucleus counter.
The results for a track approximately 35 km downwind of the city at three
separate levels are shown in Figure 24. Plotted is the combined concen-
tration of SC>2 and 002 i-n parts per million (ppm) . An air pollution sta-
tion in East St. Louis, Illinois, operated by the Illinois State Environ-
mental Protection Agency measured S02 concentrations of 0.04-0.05 ppm
during the hours of the flight.
The region of enhanced concentration which is present at all three levels
is probably indicative of a localized source in the Alton, Illinois area.
The concentration appears to increase with height; the high concentration
at about 1100 m is consistent with the presence of a stable layer at
700-1100 m upwind and over the city, and at slightly higher levels down-
wind of the city. The stability would act to dampen any turbulent or
convective mixing between the low levels and levels above the stable layer.
The higher concentration of S02 at about 1100 m on the downwind pass is
also consistent with the concentrations of condensation nuclei found on
this flight. A portion of this data is listed in Table 6. The condensa-
tion nucleus concentration increases drastically downwind from the city
at 1100 m elevation where the inversion is somewhat higher.
59
-------
r*--
CM
I I
00
CSJ
\O
00
3
J
CNJ
o
oo
CD
vO ^T CM
CD* CD* CD*
s s
• •
CD CD
CD CD1
CM
E
CD
r—4
|
'
D CD C
d- CM
CD
1 —
i — i
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LU
§
h-
CM
D^
D* CD*
CM
O •
-------
Table 6. CONDENSATION NUCLEI: AUGUST 16 AIRCRAFT SOUNDING.
Location of
Flight Track
Upwind of City
Over City
Downwind of City
Condensation Nuclei Concentration
in Air
(cnT3) x 1CT4
600 m
1.9
5.0
4.0
900 m
5.0
5.0
4.1
1100 m
0.11
0.14
6.0
61
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SECTION VII.
ANALYSIS OF RESULTS
The various alternative approaches to modeling precipitation scavenging
in the urban environment were described in Sections IV and V. We have
chosen to couch the results of this initial phase of the study in terms
of evaluation of scavenging fluxes and rates which would form the scav-
enging input to a more comprehensive material balance model for the RAPS.
The analysis of the August 1972 results necessarily must be confined in
a quantitative sense to calculation of those entities as they were ob-
served for particular convective storms. Beyond that, we hope to show
the extent to which development of the various modeling approaches are
possible and useful; current and future convective storm data will be of
importance in validating and testing these approaches.
CHEMICAL ANALYSIS
The results of chemical analyses of the precipitation samples are listed
in Table 5. Gaps in the data indicate either lost or spoiled samples or
insufficient rain volume available for analysis. Each analysis required
a separate volume of water; about 50 ml or 0.15 cm of rain was required
to perform all six analyses. The only unsatisfactory overall analysis
run was that for nitrate for Run 1. The sensitivity was very poor; con-
centrations that were apparently very high were judged too doubtful for
reporting due to uncertainty in the calibration.
Some of the later run samples were returned to Richland, Washington, for
repeat analyses for nitrate and NH/ ; the chromotropic acid analysis, an
independent means of determining nitrate content, was also performed on
several samples. Good agreement was observed between the two methods of
nitrate analysis on the average, but there was a scatter of about + 15%
on individual samples. The second analysis for ammonium ion, which took
place after several stages of thawing and freezing for prior analyses,
showed systematically higher readings than the first analysis. Some
63
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recent work, which will be described in a later report, indicates that
with aging and handling there appears to be an increase in apparent ammon-
ium content. In view of these developments, which are still under study,
we are placing greater value on the first measurements, which are those
listed in Table 5.
AVERAGE RAINWATER CONCENTRATIONS
The average pollutant concentrations for each sample line are listed in
Table 7. These can give some insight into relative rainwater content at
various distances from the city both up- and downstorm, but the upstorm
values—particularly 4A and 5A—do not necessarily represent background
concentrations. Though the general storm motion was west to east in these
runs, the low-level air entered from the opposite direction. Thus, sig-
nificant scavenging of urban pollution could have taken place over Line A.
These data are certainly too limited to lead to firm conclusions, but their
consistency and magnitude somewhat lower than the Line B average concen-
trations suggests that this low-level effect—possibly due to washout only
—is smaller than the general downstorm scavenging effects. It should be
noted, however, that residence times of pollution within the storms also
affect relative positions of uptake of pollution and deposition on the
ground, it is interesting to note here the strikingly similar concentra-
tions on Line A and C of Run 4. The intensity of the storm as it developed
from the city eastward may possibly have removed a large part of the urban
pollution output before Line C. Though the rainfall on Lines A and C are
not directly related in terms of continuity of rainfall across the entire
area, the similar concentration values may be a result of sampling of back-
ground concentrations.
We do not report any S02 concentrations; no rain sample was found to have
a significant amount of S02 present. These results are not surprising,
inasmuch as the solubility of S02 in water is greatly reduced when the
concentration of hydrogen ions is high. The acidity of the St. Louis
area rain was found to be uniformly high, as the tables show. It would be
expected, however, that significant concentrations of 862 would be found
64
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Table 7. SAMPLING LINE AVERAGE CONCENTRATIONS:
AUGUST, 1972.
Concentration3
(gm-moles/1) x 106
Run/Line
1/B
2/B
3/C
3/B
3/A
4 /A
4/B
4/C
5/A
S04~
40.1
171.
144.
172.
176.
59.4
98.2
63.2
59.9
N02~
0.16
0.42
0.21
0.10
0.13
0.28
0.44
0.12
0.09
N03~
b
121.
51.4
169.
156.
54.2
72.1
61.2
c
NH4+
17.1
33.0
30.8
66.3
52.9
19.4
23.9
19.4
c
H+
114.
87.5
125.
170.
181.
42.6
46.7
44.7
c
Q
All S02 concentrations were Insignificant.
Analysis unsatisfactory.
Insufficient water for chemical analysis.
in rain sampled near local strong sources, despite the high overall
acidity; apparently all the samples collected during the current study
were not affected by local sources.
We must also note here that though the nitrite average data are listed
in Table 7 and in subsequent analyses, the observed irregularity of the
concentrations along sample lines as compared with the major species, as
well as the generally very low concentrations, gives the impression that
local sources (such as highway traffic) may be more important for nitrite
than overall urban sources. Thus they are listed for comparison only, and
should not be considered seriously as an indication of the overall urban
nitrite source effect on scavenging.
65
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SCAVENGING FLUXES AND RATES
In order to calculate the scavenging rates using Equation (15), we must
first evaluate the individual scavenging fluxes. These can be derived
from the measured concentrations, as the flux is just the product of the
concentration and the rainfall rate J = V/ctTr, where V is the volume of
rainfall collected, a is the area of one collector and Tr is the time of
rainfall at the collector site. Two complicating factors msut be con-
sidered, however. First, an evaluation of Tr must be made, since the time
of rainfall is not in general the same as the total collection time Tt;
i.e., there often was a period of time prior and/or subsequent to the
rainfall during which the sampler was deployed. This evaluation must be
done by estimation from raingage records. The second factor to consider
is that the measured concentration of pollutant was actually the total con-
centration resulting from both dry and wet deposition processes. In fact,
the total flux F is
F = d + w, (16)
where d and w refer to dry and wet, respectively. In terms of measured
quantities, this is
V/aT = d + Cr V/aTr . (17)
We made no measurement of d during this study, but if it can be ascertained
somehow that d was small compared to w, then it would be assumed that
Cr = Ct, and the rain flux can be calculated with T provided by an examin-
ation of raingage records.
Estimate of Dry Deposition Flux
The dry flux d is often defined as the product of the air concentration x
(at the ground surface or some reference level) and a deposition velocity
V(j, which is ostensibly a function of the particle size and chemical and
physical properties of the pollutant. Any significant vertical motion of
66
-------
the air near the ground should also affect the value of v-,. We measured
neither x nor vd directly during this study, but reasonable estimates may
be made of them which will aid in evaluating any dry deposition impact on
our concentration data. Table 8 lists selected urban and nonurban air
concentrations as reported by the National Air Surveillance Networks for
1968.1-* There were no data reported for urban St. Louis, but East St.
Louis, Illinois, is included, which may be more relevant to our downstorm
measurements. Also in Table 8 is an estimate of deposition of material
of the listed air concentration, if the deposition velocity v,j = 5 cm/sec.
This value is conservatively high, being equivalent to the settling vel-
ocity of a particle of radius 20 microns.-'-"
Scavenging Fluxes
The observed total flux values for our samples were in general much higher
than the rough estimates for dry deposition in Table 8. Thus, for the
purposes of calculating the rain fluxes and scavenging rates for the
sample lines, it was assumed that Cr = Cf Figures 25 to 29 show the
rain scavenging fluxes plotted as a function of sample position (y coor-
dinate) along the sample lines. The sampling positions are located on
Figure 9. Hourly data from the Illinois State Water Survey rain gage
network were used to estimate Tr, the time of rainfall. These estimates
were aided by our field notes concerning rainfall start and stop times.
On runs when the total sampling and rainfall times were fairly short,
errors of up to + 50% are possible in the flux data, as the raingage data
reported only the amounts within a given hour. The total sampling times
were kept as short as possible, however, so that Tr averaged about 75%
of Tt. It is therefore advisable to consider the flux data of Figures 25
to 29 as only for comparison, rather than as exact expressions of the
rain flux. In subsequent calculation of the scavenging rates, involving
summation over the sample line, the errors tend to cancel somewhat. Most
of the rainfall volumes used in calculating the fluxes are those which we
measured in our collectors. These amounts agreed reasonably well with
amounts interpolated from our maps made from the Illinois State Water
Survey precipitation data (Figures 11, 14, 18, and 20). The raingage
data were used, however, to fill in missing sampler amounts on Run 4,
Line B.
67
-------
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19 21 23 25 27 29 31 33 35 37 38
SAMPLING POSITION
FIGURE 25. RAINFALL AND RAIN POLLUTION FLUXES, RUNS 1 AND 2.
69
-------
cxi
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0.8
0.6
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146 148 150
152
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61 62 63 64 65
66 67 68 69 70 71 72 73
SAMPLING POSITION
74 75
FIGURE 26. RAINFALL AND RAIN POLLUTION FLUXES, RUN 3.
70
-------
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73
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Examinations of Figures 25 to 29 reveal that some of the low-rain samples
had fluxes which were not large compared with the dry flux estimates made
above. These then may be considered doubtful as rain fluxes, due to the
possibility of significant dry deposition present.
Scavenging Rates
As we noted in Section V, containment of the rainfall, but not necessarily
containment of the city's plume, was considered a requirement for calcu-
lation of scavenging rates. We should caution, however, that the calcu-
lated rates for individual lines only reflect the scavenging conditions
which apply to the locale of the sampling line. For example, the Run 2
rain collection, because of timing of setout, contained the rainfall of a
portion of the main shower, slightly to the side of the main shower, and
trailing it in time. Thus the source of pollution contributing to the
scavenging rate is generally in doubt; in most cases, it is expected that
only a portion of the city's output is involved, plus possibly a contribu-
tion from washout of low-level air moving from a direction different from
that of the motion of the storm.
The scavenging rates, calculated from Equation (15) using the rain flux
data, are shown in Table 9. Run 3, Line B, and Run 5 are not included
because of insufficient containment of the rainfall. In the case of Run 4,
Line A, the gap in the rainfall required that the two portions be separated
for scavenging rate purposes, but it is noteworthy that the two apparently
different showers {of. Figure 20) resulted in roughly the same scavenging
rates. As noted above, the nitrite data possibly reflect local source
contributions more than the other species, so nitrite scavenging rates are
included only for a rough comparison with the others.
In relating scavenging rates for different lines of the same run, it is
true that the relationship will not be the same as that for the average
concentrations, as listed in Table 7. The scavenging rate results essen-
tially from the average flux, which includes the effect of rainfall rate.
For example, the 4C concentrations were similar to the 4A concentrations,
but the rainfall rate was much higher on Line C, leading to a higher scav-
enging rate.
74
-------
Table 9. SCAVENGING RATES: AUGUST, 1972.
Scavenging Rate
(gm-moles/cm sec) x
Run/Line
1/B
2/B
3/C
3/Ab
4/A (North)
4/A (South)
4/B
4/C
so4-
0.92
6.62
10.3
8.49
2.21
3.83
192.
18.0
N02~
0.002
0.014
0.009
0.006
0.028
0.004
0.516
0.024
N03~
a
6.60
11.5
7.33
2.92
3.55
128.
22.1
106
NH4+
0.32
1.84
6.52
2.49
0.97
1.37
55.4
10.9
Tfo measurement.
Rain not sufficiently contained on 3/B.
In general, the scavenging rates, which express the rate of removal of
pollution in terms of mass per unit time per unit distance, do not give
much insight into more absolute rates of removal which reflect the magni-
tude of the pollution source. But with Run 4, we have independent measure
of scavenging rates for two distances downstorm. These data allow very
crude integration of the removal over the x direction. If we assume that
there is no further source of pollution to the storm between Lines B and
C, i.e., that the airborne pollution at Line B can only decrease by scav-
enging as it moves downstorm, the fractional removal is
= W(line B) - W(line C)
BC W(line B)
(18)
A more useful calculation, but equally crude, involves carrying the inte-
gration of the last term of Equation (14) one more step to include the
x direction. We have calculated
75
-------
rb v (wi+
W =/ w (x,y) 3y =>
(moles/cm sec).
(15)
The next step, which for Run 4 involves just a two-step approximation to
the integration, is
W(XB) + W(xC)
W(x) 3x = ~2 [XB - XG] (moles/sec),
(19)
where x_ and
o
are the distances from the St. Louis arch to Lines B
calculated for
and C, respectively. Table 10 lists values of F and
15 C
Run 4; the latter compared with approximate 1963 emission rates for
St. Louis County, and St. Clair County, Illinois (E. St. Louis).
Clearly, the simple averages derived from consideration of only two points
downs torm can only give a rough estimate of the magnitude of the scavenging
effect of this particular storm, but it is noteworthy that — though the
exact pollution source is unclear — the deposition in one downs torm area
was comparable to the emission in the urban area.
Table 10. FRACTIONAL REMOVAL AND RATE OF REMOVAL BY SCAVENGING
FOR RUN 4, LINES B AND C.
Pollutant
so4=
N03~
NH.+
4
Approximate St. Louis
n Emission Rate - 1963 17
BC (moles/sec) (moles/sec)
0.91 189. 69.
0.83 135. 39.
0.80 60. a
available.
76
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APPLICATION OF A COMPREHENSIVE STORM MODEL FOR SCAVENGING ANALYSIS
The two-dimensional convective storm model mentioned previously in Section
IV has been applied for limited analyses of the 1972 field results. As
noted previously, this model is essentially a solution of the transient
conservation equations for mass, water vapor, liquid water, momentum, and
energy, subject to appropriate constraints and boundary conditions, and is
o
described in detail elsewhere.
The approach that has been utilized thus far involves first obtaining a
realistic storm cell circulation using the model in conjunction with mea-
sured environmental conditions. Steady state motion and liquid water
fields are then assumed and a plume of pollutant is inserted ahead of the
storm. Subsequently, three separate calculations are performed, each more
complicated than the one preceding.
1. The air motions in the storm are allowed to redistribute the mater-
ial, with no interaction with rain.
2. Same as 1., except that below-cloud scavenging processes are added.
3. Same as 2., except that in-cloud scavenging processes are added.
An example of the results of 1. is presented in the following pages,
while 2. and 3. are included in future research plans. Since the form of
the pollutant plume on the day in question was not measured by aircraft,
future calculations will be performed using several initial spatial
distributions of the pollutant to be scavenged. The calculated deposi-
tion patterns resulting from diverse initial conditions and processes may
then be compared with the observed pattern.
TEST CASE: ENVIRONMENTAL CONDITIONS AND RESULTS OF CALCULATIONS
The squall line thunderstorm model has been applied for a test case using
the environmental conditions existing in the St. Louis area on August 21,
1972, the day of Run 4. The storm which occurred on that day possessed
several squall line characteristics. The rainfall pattern is shown in
Figure 20 as measured by the raingage network operated by the Illinois
State Water Survey. Amounts in excess of three inches were measured in
southeast St. Louis and directly across the Mississippi River in Illinois.
77
-------
The elongated rainfall maximum in the northern section of the area
resulted from the movement of a separate cell toward the east-northeast.
The rainfall pattern in the south part of the city represents the move-
ment of individual cells in an easterly direction, but with development of
new cells quasi-continuously on the right flank. The result of this was
a propagation toward the southeast.
The wind, temperature, and moisture profiles were measured at approximately
1400 CST, a few hours prior to the storm's occurrence. The winds which
were used in the two-dimensional model calculation were the components of
the wind in the direction of storm motion (taken to be from the northwest
(315°)). The resulting wind profile is shown in Fig. 30. Actually two
wind profiles were used in the model calculations, one profile to the left
and one profile to the right of the storm, so as to produce low level con-
vergence and upward motion. The profile shown in Fig. 30 is actually the
mean of these two profiles. The temperature, water vapor mixing ratio,
pressure, and air density as shown as functions of height in 400 m incre-
ments in Table 11.
The model calculations were initated by allowing the area of upward motion
to produce a convective cloud. The evolution of the cloud is represented
by the time variation of several parameters shown in Fig. 31. The model
was run for about 60 minutes until a fairly regular oscillatory time evolu-
tion of the cloud circulation was obtained. A time was chosen (about 55
minutes) when a typical cloud circulation was occurring. The motion field,
rainwater mixing ratio distribution and cloudwater distribution were then
assumed to be fixed in time for purposes of experimentation with pollutant
inclusion into the storm. The streamfunction, representing the motion
field, is shown in Fig. 32. A pollutant distribution was then introduced
in the lower 2 km of the atmosphere upwind from the storm. The pollutant
was then allowed to travel with the air motion (motion field is that rela-
tive to the moving storm, translational speed has been removed) and not
allowed to interact with the rain or cloud. The distribution was allowed
to enter through the right boundary for a limited amount of time corres-
ponding to the finite width of a pollutant over an urban area.
78
-------
12.8
12,0
112
10.4
9.0
8.8
8.0
= 7'2
£ 6.4
£ 5.6
4.8
4.0
3.2
2.4
1.6
0.8
0
I
I
-5 -4 -3
-2-10 1 2
WIND SPEED (m/sec)
FIGURE 30. COMPONENT OF THE WIND IN THE PLANE OF MOTION OF THE STORM
AS A FUNCTION OF HEIGHT FOR THE 21 AUGUST 1972 STORM.
79
-------
Table 11. VARIABLES OF STATE AND WATER VAPOR MIXING RATIO AS A FUNCTION
OF HEIGHT USED AS ENVIRONMENTAL CONDITIONS FOR MODEL CALCULA-
TIONS . BASED UPON OBSERVATIONS TAKEN AT LAMBERT FIELD, ST.
LOUIS, MISSOURI ON 21 AUGUST 1972 AT 1417 CST.
Ht. (km)
0.0
0.4
0.8
1.2
1.6
2.0
2.4
2.8
3.2
3.6
4.0
4.4
4.8
5.2
5.6
6.0
6.4
6.8
7.2
7.6
8.0
8.4
8.8
9.2
9.6
10.0
10.4
10.8
11.2
11.6
12.0
12.4
12.8
P (mb)
990.
947.
905.
865.
826.
788.
751.
716.
682.
649.
618.
588.
559.
532.
505.
480.
455.
432.
409.
388.
368.
348.
329.
312.
295.
278.
263.
248.
234.
220.
207.
195.
183.
T (°C)
35.2
30.4
26.0
21.6
17.5
14.0
11.8
8.7
5.7
4.2
2.7
1.1
-1.1
-3.6
-6.9
-9.8
-12.3
-14.6
-16.7
-18.7
-21.1
-23.5
-25.9
-28.3
-30.7
-33.5
-36.3
-39.1
-42.2
-45.4
-48.7
-52.0
-54.2
qv (g/kg)
15.542
14.526
13.305
12.193
11.503
11.216
8.691
6.264
4.429
4.238
3.825
3.317
2.707
2.182
1.844
1.511
1.187
.896
.664
.448
.377
.307
.251
.207
.163
.131
.104
.077
.057
.045
.033
.021
.015
P (kg/m3)
1.1082
1.0775
1.0458
1.0147
.9828
.9492
.9134
.8812
.8492
.8130
.7782
.7450
.7146
.6861
.6600
.6339
.6075
.5816
.5559
.5312
.5080
.4857
.4641
.4433
.4233
.4045
.3865
.3690
.3525
.3368
.3216
.3069
.2914
80
-------
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-------
The resulting redistribution of the pollutant by the storm circulation is
shown in Fig. 33 at four different times. It can be seen that most of the
pollutant is transported to the upper atmosphere while another significant
part is retransported to lower levels in the storm downdraft. This portion
which is transported to the lower levels would have ample opportunity to
be scavenged by cloud and rain since it traverses both the updraft and
downdraft. The portion of the pollutant which remains in the upper levels
might not be scavenged so effectively. An examination of the circulation
pattern within the storm reveals that the air which comprises the down-
draft originates in the lowest levels prior to its incorporation into the
storm. Therefore, if it is true that pollutant traversing both the updraft
and downdraft is scavenged most effectively, the fraction of pollutant
which is ultimately scavenged depends to a very large extent upon the
vertical distribution of pollutant prior to its entry into the storm.
A next step in this ongoing research will be to determine the extent to
which the pollutant traversing various parts of the storm will be scav-
enged by cloud and rain. This will involve invoking realistic assumptions
regarding the interaction of the pollutant with falling rain, and finally
assumptions regarding the interaction of pollutant (either as a condensa-
tion or as a dissolved gas) with the cloud droplets. Regarding the latter
interaction, the pollutant may have to be considered in a less passive
manner in its effect upon the evolution of the storm. This approach and
others listed in Section IV will be pursued in subsequent stages of this
research; the modeling results will form an important part of future
reports.
83
-------
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84
-------
SECTION VIII.
REFERENCES
1. Ludlam, F. H. Severe Local Storms: A Review. Meteorological
Monographs. 1(27):33-58, 1963.
2. Newton, C. W. Structure and Mechanism of the Prefrental Squall
Line. J. Meteor. ^7:210-222, 1950.
3. Engelmann, R. J. Scavenging Prediction Using Ratios of Concentra-
tions in Air and Precipitation. In: Precipitation Scavenging (1970),
Engelmann, R. J., and Slinn, W.G.N., eds. Oak Ridge, Tennessee, USAEC
p. 475-485. December, 1970.
4. Engelmann, R. J. Scavenging Prediction Using Ratios of Concentrations
in Air and Precipitation. J. Appl. Meteor. 1.0:493-497, June 1971.
5. May, F. G. The Washout of Lycopodium Spores by Rain. Quart. J. Roy.
Meteor. Soc. 84:451-485, 1958.
6. Hales, J. M., J. M. Thorp, and M. A. Wolf. Field Investigation of
Sulfur Dioxide Washout from the Plume of a Large Coal-Fired Power
Plant by Natural Precipitation. Battelle, Pacific Northwest Labor-
atories. Richland, Washington. March 1971.
7. Hales, J. M. Fundamentals of the Theory of Gas Scavenging by Rain.
Atmos. Environ. (London) 6;635-659, 1972.
8. Hane, C. E. The Squall Line Thunderstorm: Numerical Experimentation.
J. Atmos. Sciences. JO:1672-1690, 1973.
9. Scaringelli, F. P., B. E. Saltzman, and S. A. Frey. Spectrophoto-
metric Determinations of Atmospheric Sulfur Dioxide. Anal. Chem.
J39:1709, 1967.
10. Lazrus, A., E. Lorange, and J. P. Lodge. New Automated Microanalysis
for Total Inorganic Fixed Nitrogen and for Sulfate Ion in Water. In:
Trace Inorganics in Water. ACS Advances in Chemistry Series Number
73. Washington, D.C., American Chemical Society, 1968.
11. West, P. W., and T. P. Ramachandvan. Spectrophotometric Determina-
tion of Nitrate Using Chromotropic Acid. Anal. Chim. Acta. 35:317,
1966.
12. West, P. W. Chemical Analysis of Inorganic Particulate Pollutants.
In: Air Pollution, Stern, A. C., ed., New York, Academic Press, 1968.
85
-------
13. Saltzman, B. E. Anal. Chem. ^6:1949, 1954.
14. Dana, M. Terry, J. M. Hales, and M. A. Wolf. Natural Precipitation
Washout of Sulfur Dioxide. Battelle, Pacific Northwest Laboratories.
Richland, Washington, pp. 23-32. February 1972.
15. Air Quality Data for 1968. U. S. Environmental Protection Agency.
Research Triangle Park, North Carolina. APTD-0978. August 1972.
16. Gunn, R., and G. D. Kinzer. The Terminal Velocity of Fall of Water
Droplets in Stagnant Air. J. Meteor. £:246, 1949.
17. Venezia, R., and G. Ozolins. Interstate Air Pollution Study:
Phase II Project Report, Part II. Air Pollutant Emission Inventory.
USHEW, Public Health Service. Cincinnati, Ohio. December 1966.
86
-------
SECTION IX.
NOMENCLATURE
Units: 1 = length; t = time; none = dimensionless
b Length of sampling line in x direction, 1
c , c Concentration of pollutant (A) in rainfall from scavenging,
moles/1
c Concentration of pollutant in collected rain sample from
scavenging and dry deposition, moles/l^
2
d, d Dry deposition flux of pollutant (A), moles/1 t
A
E- Efficiency of cloud in removing water from air entering it
f Fraction of particles which nucleate cloud droplets and
are subsequently removed
F Total flux to surface from both dry and wet deposition,
moles/I2t
F Fractional removal of pollution between Line B and Line C
H Height of cloud base, 1
i Subscript: initial, or summation index
J Rainfall rate, 1/t
k. Rate of removal of pollutant A from gas phase by hydro-
meteors, t"1 1~3
m. Mass of pollutant A in atmosphere, moles
mf Mass of material leaving (washout ratio) storm system in
air, moles.
m. Mass of material entering (washout ratio) storm systems in
air, moles
moA
Initial mass of pollutant A source, moles
m Mass of material leaving (washout ratio) storm system in
precipitation, moles
87
-------
n Number of precipitation collectors along sampling line
q Absolute humidity of air entering (washout ratio) storm
system, moles/1^
Q . Rate of emission of pollutant A, moles/t
r Generation rate of pollutant A by chemical reaction, t~
r Rate of production of pollutant A in gas phase, t~
Ag
r... Rate of production of pollutant A in liquid phase, t~
r Ratio of concentrations of pollutant in water and air at
ground level (washout ratio)
t time
T Time of rainfall at collector site during collection, t
T Total time of sampler deployment, t
u Mean wind speed, 1/t
V Volume of rain sample, 1
v.. Velocity of pollutant A in gas phase in ith direction
(i = x,y,z), 1/t
v. Average velocity of pollutant A in gas phase, 1/t
Ag
vA1 Average velocity of pollutant A in liquid phase, 1/t
AJ~
2
w, w. Flux of pollutant (A) to surface by scavenging, moles/I t
A
W Scavenging rate, moles/1 t
x Distance downwind (or downstorm) from source, 1
x,,, x0 Average distance from St. Louis Arch to Line B, Line C, 1
13 C
y Distance across plume (or storm), 1
y. Coordinate of ith precipitation collector in y-direction, 1
z Height, 1
88
-------
2
a Area of precipitation collector, 1
3 "Reactivity factor" from washout ratio analysis
Ax,Ay,Az Dimensions of material-balance system in coordinate directions, 1
A Washout coefficient, t
3
p Density of water, moles/I
3
p. Molar density of pollutant A in gas phase, moles/1
Ag
3
p.. Molar density of pollutant A in liquid phase, moles/1
3
X, X* Air concentration of pollutant (A) moles/I
ft Removal rate by precipitation scavenging, moles/t
89
-------
SECTION X.
APPENDICES
Page
A. Field Results for Summer 1973 93
B. Some References Pertinent to the Field of Precipitation
Chemistry 121
91
-------
APPENDIX A: FIELD RESULTS FOR SUMMER 1973
As noted in the introduction to this report, unanticipated changes in
program planning have led to the temporary discontinuation of this
project. Consequently the results for the summer 1973 field period are
presented here in rather brief form, hopefully for the benefit of others
who may be conducting future research in this area. These results are
composed primarily of rain-concentration and sounding information. De-
tailed synoptic material is currently on file at BNW but has not been
included in this Appendix.
The study of precipitation scavenging mechanisms affecting removal of
metropolitan-source pollutants proceeded with a second summertime field
program in the St. Louis area. As during the August, 1972 effort, rain
samples from convective storms were collected and chemically analyzed for
several pollutant species. Support operations included rawinsonde re-
leases, aircraft measurements, and radar observations. A considerably
expanded field operation was successfully maintained, however, through a
cooperative effort with other Battelle projects in the area. Extension
of the spatial and temporal capabilities of the sampling array, plus
additional aircraft flights with more instrumentation allowed us to add
a considerable body of experimental results which will prove beneficial
in ongoing precipitation scavenging model development and testing. This
appendix describes progress in collection and analysis of data from the
July, 1973 field work, and initial developments in the modeling program.
Experimental Procedure
With the exception of the additions described below, the procedure for
collection of rain samples and meteorological data was the same as during
the August, 1972 field program. The field director at Lambert Field
National Weather Service station (STL), observed the meteorological radar
and alerted the field crew for deployment of samplers in anticipation of
rainfall. The sampling array, which consisted of three sampling lines in
1972, was expanded to form the grid of 120 sample positions shown on
93
-------
page 95. This new network included the original western (upstorm) line,
plus a downstorm grid which extended from 2 to 52 km east of the St. Louis
Arch ("*" on figure). Maintenance of this extended array was achieved
through cooperation with a concurrent Atomic Energy Commission research
effort, which employed several students as field workers in addition to
Battelle personnel. The additional manpower allowed essentially all the
sampling positions to be maintained on each storm day. We had found in
1972 that the dry ice freezing rain collectors remained effective for
several hours prior to rainfall; thus the entire grid could be set out
during the mornings of likely storm days. We then were able to operate
with a minimum of short-term forecasting of storm direction and speed.
Short-term forecasting was used, however, for directing the placement of a
sequential rain collector, new this year. The sampler, shown on page 96,
2
consisted of a 1 m plastic funnel mounted on an automobile. Sufficient
rainwater to constitute a sample could be col cted over time intervals as
short as 30 seconds. The sampler was directed—when time allowed—to near
the center of the anticipated rainfall pattern; in all three cases of use,
samples were taken from the onset of rain through the duration of the
shower.
Another addition to the field operations was a radio system which allowed
near-continuous contact between the field director and most of the field
crew. Contact was also maintained with personnel at the METROMEX radar
center at Pere Marquette State Park, Illinois, and thus with operating
aircraft and forecasters. This communication link was deemed useful in
coordinating field operations and forecasting among all the active
researchers.
Precipitation Scavenging Results
The table on page 103 lists general data on the storms sampled during the
field period of July 9-July 27, 1973, plus radiosonde release times and re-
mains on the various runs. Temperature-dew point profiles and wind data
resulting from the radiosonde flights are shown in figures, pages 97-102.
As was the case with the 1972 field program, much of the rainfall was
associated with quasi-frontal or squall-line activity, and the rainfall
94
-------
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LAMBERT FIELD - ST. LOUIS
JULY 19, 1973 1329 CST
1929 Z
/ SATURATION
ADIABAT
DIRECTION - SPEED
(DEGREES - KTS)
TEMPERATURE
E
LLJ
a:
ex.
Q-
800
900
1000
TEMPERATURE T
JULY 19, 1973 RADIOSOUNDING
97
-------
LAMBERT FIELD - ST. LOUIS
JULY 20, 1973 1241 CST
1841 Z
SATURATION
ADIABAT
DIRECTION - SPEED
(DEGREES - KTS)
TEMPERATURE
I/O
l/l
700
800
900
1000
110
120
TEMPERATURE F
JULY 20, 1973 RADIOSOUNDING
98
-------
LAMBERT FIELD - ST. LOUIS
JULY 21, 1973 0928 CST
1528 Z
SATURATION
ADIABA1
TEMPERATURE
XWIND
DIRECTION - SPEED
(DEGREES - KTS)
cc
=>
I/O
800
900
90
100
1000
110
120
TEMPERATURE F
JULY 21, 1973 RADIOSOUNDING
99
-------
LAMBERT FIELD - ST. LOUIS
JULY 23, 1973 1323 CST
1923Z
WIND
DIRECTION - SPEED
(DEGREES - KTS)
oc
Q.
110
120
1000
TEMPERATURE UF
JULY 23, 1973 RADIOSOUNDING
100
-------
\ / \
LAMBERT FIELD - ST. LOUIS
JULY 24, 1973 1256 CST
1856Z
-20
/
TEMPERATURE
SATURATION
ADIABAT
WIND
DIRECTION - SPEED
(DEGREES - KTS)
278 20
TEMPERATURE T
JULY 24, 1973 RADIOSOUNDING
o:
3
l/l
UJ
Q-
700
800
900
1000
120
101
-------
LAMBERT FIELD - ST.LOUIS
JULY 25, 1973 - 1308 CST
WIND /
DIRECTION - SPEED
(DEGREES - KTS)
233 V24
20
TEMPERATURE
ac.
a.
800
900
70 80 90
TEMPERATURE °F
JULY 25, 1973 RADIOSOUNDING
110
120
1000
102
-------
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cu o>
N >
o o
M CJ
Jj
CO
0) CU
rH 4J
p, cd
S -H
a -o
en cu
4-> B
en -H
o
S
0
0
oo
rH
1
O
o
vO
rH
•"3"
CN
f^
|
N^f
M
0
VO
CO
^^
1
rH
1
|
C
0
•H
4J
CJ •
CU C
rH 0)
rH N
O O
U to
(4_j
4_) pj
J3 3
60
•H 4J
C CD
M O
> e
o
/-N
1 — 1
1
N— ^
CT»
CN
CO
rH
O
O
o
rH
1
0
0
CO
0
o
o^
f}
rH
o
CO
CO
•*
(^
1
O
(^
CO
1^
1
CTi
rH
«^^_
CO
rH
1
CO
cu
rH
P.
B
cB
CO
cu
rH
_Q •
cfl T3
CU 01
CO >
3 co
CO
o
53
CD r7
CN CN
1 1
*^S NW*
i-H 00
s± CN
CN CT\
rH O
*r*
M rH
4H rH
C 0
3 CJ
rH 0)
I-H 4-1
CO CO
•H
1 ^3*
o>
•*-* B
r] g
60 -H •
•H G
g« O
C -rl
CU CU 4-1
^
O
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CJ
01
rH
rH
O
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^1
cd
*"O
CU
B
CD
CO
oo
0
CO
rH
^
PM
^
rH
M
Cfl
W
"^
rH
vO
1
CO
CN
H
CO
r^
I
m
CM
I
•
C
cu
to
o
MH
4-1
CO
0
B
cu
N
0
m
rH
rH
CO
1
rH
cd
•H
U
C
cu
3
cr
cu
CO
o
o
CM
CM
1
o
o
rH
CN
00
O
o
CO
CO
rH
CO
p^
1
CN
1
l~-
O
M
4-1
c
3
4-1
CO
o
B
1
4-1
f)
60
•H
C C
M cu
01 N
J>
O
s
PH ^
CN
0) *^
••-j r**.
cd
,j
Q\
LO
fx.
i
vO
«i
CO
1
o
sf
rH
CO
p^
1
vO
CN
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m
CM
I
f^
•
M
cu
C
C
0
•H
4-J
•H
CO
O
p.
cu
"g-
cd
CO
cu
.c
4J
U-J
O
4-1
•rH •
60 13
•H CU
T3 4J
cd
4J O
CO iH
to 13
•H _C
'rl
CU C
rC O
4-1 -H
4J
?*v "rH
rQ CO
O
cu
•H 4-1
K-l CO
•H
•W C
C CU
0) vj
T3 cd
•H 4-1
cu co
to CU
CO rH
p.
p. §
3 co
o
Ml
rH
60 cd
•H
M 4-1
0) fi
rH Q)
P, 3
B cr
cd cu
CO CO
cd ,0
103
-------
was often spread over the majority of the sampling area. The sampling
groups (located on Figure 33) are identified by the first digit to the
sampling position number. Four of the nine runs involved overnight collec-
tions, as we followed the policy of leaving the sampling stations equipped
at all times. This policy proved feasible after several unsuccessful storm
days early in the field series left us with the samplers deployed at night-
fall. The remarkable lack of vandalizing of samplers prompted us to take
advantage of overnight collections. However, the overnight collections
were generally unfrozen at pickup because of dissipation of dry ice.
There were notable exceptions which confirmed the ability of the samplers
to remain effective even after long setout times: the four samples of
Run 11 (a very isolated shower) were collected frozen despite 24 hours of
exposure. The runs of July 25-26 are numbered loosely on the basis of
pickup times; many separate showers were sampled during that period, and
final sorting will have to await analysis of data from the raingage net-
work maintained by Illinois State Water Survey.
The chemical analyses for the species S02, SO,, NO, NO ~ NH, , and
H were conducted during the two-month period following the field trip.
All samples had been kept frozen and shipped by air to Richland, Washington.
Our decision to confine the analyses to our home laboratory rather than in
the field have proved beneficial, as the analysis of some 400 samples would
not have been nearly completed during the field period. The measured con-
centrations of pollutants are listed in tables, pages 105-119. Many notes
were taken regarding unusual aspects of the collection (such as evidence of
tampering, frozen or unfrozen, etc.); these have not been fully evaluated,
but certain samples are merely noted at this time as being suspicious.
Thus the concentration data should be currently regarded as rather raw,
pending further examination of sampling conditions, possible degradation of
the samples due to exposure at ambient temperature, etc.
Initial observations of results of repeated analyses seem to indicate that
our original fears regarding loss of ammonium ion and chemical reaction of
other constituents may have been largely unfounded. Further study is nec-
essary, but it appears that exposure to room temperature for up to two days
104
-------
CONCENTRATIONS OF INORGANIC, NONMETALLIC
POLLUTANTS - RUN 6, JULY 14, 1973.
Sample
Position
014
015a
016
401
405
407
411
417
419
421
423
501
503
505
521
601
602
603
604A
604B
605
606a
607
Rainfall
cm
0.11
0.40
0.05
0.13
0.09
0.10
0.03
0.04
0.05
0.08
0.08
0.59
1.04
0.34
0.05
0.25
0.45
0.51
0.65
0.73
1.25
0.71
Concentration (gm-moles/1) x 10
so2
0.46
0.70
0.82
0.48
0.48
0.95
0.85
0.24
0.41
0.38
0.85
0.38
<.2
1.45
0.26
SV
78.1
175.
72.9
76.0
155.
74.0
145.
124.
113.
88.5
98.9
68.8
75.0
N02
0.48
0.31
0.30
0.27
0.51
0.26
0.35
0.45
0.31
0.39
0.28
0.11
0.15
0.22
1.08
0.40
0.27
0.27
0.15
0.12
1.15
0.05
N03
97.0
55.3
145.
180.
179.
214.
143.
130.
143.
36.4
109.
50.
142.
119.
72.2
66.9
52.0
61.9
55.2
NH.+
4
61.0
54.7
64.5
81.8
72.0
82.1
35.9
34.1
54.4
47.0
91.1
57.0
59.3
62.2
41.8
51.1
34.5
44.1
50.8
H+
2.8
15.5
35.5
25.7
95.5
<10.
58.9
309.
89.1
63.1
13.8
12.6
60.3
64.6
89.1
<10.
102.
Questionable quality - see text.
105
-------
CONCENTRATIONS OF INORGANIC NONMETALLIC
POLLUTANTS - RUN 7, JULY 18-19, 1973.
Sample
Position
007
008
009
010
Oil
012
013
014
015
016
017
018
019
020
201a
203a
205
301
303
305
307
315
317
319
321
323
403
405a
407a
409
411
413
415
417
421a
423a
425a
427
Rainfall
cm
0.08
0.13
0.20
0.25
0.24
0.29
0.27
1.42
1.17
1.18
0.80
0.74
0.74
0.76
0.15
0.10
0.09
0.75
0.26
0.21
0.21
0.21
0.79
1.36
0.41
0.33
0.72
0.88
0.31
0.63
0.57
0.42
0.30
0.39
1.21
1.57
0.35
0.72
Concentration (gm-moles/1) x 10
so2
1.26
1.37
0.46
0.59
0.39
0.90
<.l
<.l
<.l
<.l
<.l
<.l
<.l
<.l
1.23
1.52
1.14
0.21
<.2
<.2
<.2
<.2
0.22
0.64
1.02
0.20
0.98
0.31
0.35
0.31
0.68
S°4
88.5
62.5
58.3
65.6
55.2
61.5
44.8
12.5
15.6
29.2
57.3
50.5
56.8
34.4
68.0
125.
81.5
44.8
55.2
31.1
46.0
71.6
67.2
53.1
111.
102.
97.9
44.8
71.9
62.5
74.5
N02
0.60
1.18
0.46
0.67
0.41
0.10
0.11
0.07
0.20
0.74
0.09
0.06
0.72
0.07
0.11
0.63
<.l
0.18
0.10
<.l
0.56
0.67
0.07
0.07
0.08
0.19
0.08
0.10
0.16
<.l
0.07
0.16
1.62
0.75
N03
82.0
28.5
32.9
33.9
37.1
26.0
28.8
9.3
12.9
13.8
16.2
16.6
14.3
22.6
42.6
30.7
41.3
48.6
29.8
55.6
42.0
43.2
38.7
53.5
28.7
29.6
51.2
52.4
64.8
37.5
20.9
30.5
36.8
36.8
27.0
31.0
27.8
NH.+
4
14.7
8.2
7.8
3.1
7.6
14.7
11.6
10.1
8.8
11.6
16.9
9.9
14.9
19.4
36.1
14.7
14.1
10.2
13.2
12.8
14.1
25.2
21.3
12.2
10.1
11.5
23.2
13.5
28.5
14.7
7.8
16.9
8.9
15.4
22.6
9.9
15.2
H+
9.5
47.9
30.2
7.6
38.9
23.4
29.5
37.2
35.5
66.1
77.6
36.3
95.5
39.8
0.4
24.0
58.9
15.8
58.9
17.8
74.1
24.5
44.7
105.
309.
12.3
5.6
120.
91.2
129.
64.6
105.
29.5
123.
63.1
110.
2.5
2.0
106
-------
CONCENTRATIONS OF INORGANIC NONMETALLIC POLLUTANTS -
RUN 7, JULY 18-19, 1973. (Continued)
Sample
Position
501a
503
505
507
509
511
513
515
517
519
521
523
601a
602
604
605
607
608
610
611
612
613
614
615
616
617a
703a
704a
705
706
707
708
710
711
713
714a
715
716
Rainfall
cm
1.61
1.49
1.53
0.79
1.06
1.18
0.86
0.39
0.78
0.47
1.26
0.33
0.17
0.27
0.18
0.18
1.38
0.23
0.28
0.31
0.39
0.42
0.37
1.14
1.6
0.03
0.08
0.15
0.22
0.28
0.35
0.65
0.38
0.31
0.29
0.16
0.08
Concentration (gm-moles/1) x 10
so2
<.2
<.2
<.2
0.21
0.24
<.2
0.31
0.67
0.40
<.l
<.l
<.l
<.l
<.l
<.l
<.l
<.l
<.l
<.l
<.l
<.l
<.l
<.l
S°4
36.5
32.3
64.6
47.9
44.8
61.5
40.9
44.8
72.7
87.5
66.7
85.4
27.2
42.2
44.0
64.1
55.2
46.0
58.9
44.8
37.5
16.7
115.
79.0
62.5
73.4
72.7
40.6
55.7
72.4
N02
<.l
<.l
<.l
0.09
0.08
<.l
0.51
0.08
0.12
0.22
0.08
0.09
0.33
0.35
0.41
0.45
<.l
0.58
0.46
0.29
0.45
0.33
0.57
0.20
1.65
1.22
0.87
0.74
0.61
0.31
0.32
0.92
0.85
0.74
N03
13.6
18.6
12.5
34.0
33.0
30.9
18.9
26.0
30.6
21.7
16.7
21.5
31.8
33.7
52.6
11.7
20.3
50.6
44.4
37.1
30.9
28.2
20.8
91.2
68.1
54.1
48.2
55.9
25.5
21.7
88.6
NH.+
4
17.1
10.9
7.7
9.6
21.3
16.7
10.8
12.8
22.2
17.1
13.2
20.0
17.8
3.5
9.3
6.5
17.8
14.7
8.2
5.6
8.8
5.2
30.3
6.9
8.0
16.7
1.7
3.5
9.3
6.1
6.9
7.6
2.7
15.4
H+
35.5
40.7
30.2
102.
87.1
95.5
8.1
112.
63.1
50.1
69.2
37.2
23.4
50.1
41.7
45.7
61.7
53.7
1.6
45.7
46.7
15.1
53.7
60.3
8.1
10.2
25.7
10.2
31.6
12.0
24.0
30.9
38.0
24.5
47.9
Questionable quality - see text.
107
-------
SEQUENTIAL SAMPLE CONCENTRATIONS OF INORGANIC
NONMETALLIC POLLUTANTS - RUN 7, JULY 18-19, 1973.
Sample
Position
(Sequential)
A
B
C
D
E
F
G
H
I
J
K
L
M
N
Kainraxi.
Rate
cm/hr bU2
0.62 <.l
0.57 <.l
0.58 <.l
0.16 <.l
0.28 <.l
0.13 <.l
0.06 <.l
0.22 <.l
0.36 <.l
0.49 <.l
0.53 <.l
0.26 <.l
0.08 <.l
0.04 <.l
Concentration (gin-moles /I) x 10
S°4=
24.5
49.5
39.6
44.8
27.1
55.2
68.8
50.5
19.8
29.2
28.1
63.5
50.5
32.3
N02
0.35
0.07
0.06
0.07
0.07
<.06
0.09
<.06
<.06
<.06
<.06
0.09
0.08
N03
33.7
18.2
16.9
33.6
44.7
40.5
26.3
11.7
7.7
6.5
23.2
19.6
NH.+
4
15.2
9.5
13.2
24.2
36.1
24.9
15.6
8.8
4.6
2.7
11.2
10.3
H+
36.3
145.
123.
126.
100.
162.
145.
97.7
95.5
105.
95.5
75.9
108
-------
CONCENTRATIONS OF INORGANIC, NONMETALLIC
POLLUTANTS - RUN 9, JULY 23, 1973.
Concentration (gm-moles/1) x 10
Sample
Position
008
009
010
Oil
012
013
014
015
016
017
018
019
020
102a
104
106
108
110
112
114
116
118
120
122
124
201
203
205
207
209
211
213
21
217
219
221
223
225
Rainfall
cm
0.56
0.63
0.76
0.70
0.86
0.83
0.84
0.85
0.85
0.84
0.89
0.89
0.90
0.28
0.23
0.18
0.21
0.26
0.62
0.35
0.38
0.34
0.51
0.36
0.30
0.51
0.25
0.37
0.97
0.70
0.66
1.19
0.57
0.38
0.76
0.37
0.42
0.33
so2
0.24
<.2
<.2
0.22
<.2
0.24
<.2
0.26
<.2
0.78
<.2
<.2
<.2
<.2
<.2
<.2
0.63
<.2
0.63
<.2
<.2
<.2
<.2
<.2
0.36
<.2
0.56
1.01
<.2
<.2
0.81
5.08
<.2
<.2
<.2
0.35
<.2
SV
23.0
23.6
22.6
37.6
18.3
10.0
14.5
11.6
13.2
20.4
16.0
17.1
13.2
48.3
76.4
83.1
83.9
55.3
39.4
39.8
54.9
40.3
67.5
53.1
46.3
41.7
57.0
33.4
18.8
24.4
23.7
33.1
30.4
30.0
24.4
39.6
55.6
N02
<.l
<.l
0.47
<.l
0.41
<.l
<.l
<.l
0.31
0.14
0.35
<.l
<.l
<.l
0.39
0.08
0.75
0.24
0.25
0.08
0.14
<.l
0.07
0.11
0.09
0.65
0.09
0.06
0.68
.06
0.11
0.55
0.29
0.11
0.06
0.08
0.12
0.14
N03
29.5
28.5
24.7
27.3
26.4
26.5
24.5
25.7
23.6
24.7
22.3
20.3
24.4
44.1
57.7
68.8
70.9
55.1
32.2
47.7
48.3
50.6
4.1.2
51,4
51.9
49.9
56.4
59.1
53.0
28.7
45.3
27.6
23.7
39.0
26.1
35.4
42.3
57.3
NH,+
4
3.5
5.8
3.0
6.5
2.7
3.6
2.1
3.0
1.7
8.6
3.5
6.5
5.1
6.5
7.1
51.2
67.1
6.2
61.0
23.9
18.6
22.7
22.9
14.4
5.0
25.8
9.9
20.3
17.1
12.1
25.4
1.5
45.1
8.0
9.0
7.1
16.7
12.3
H+
17.8
24.5
7.6
37.2
10.5
16.2
45.7
10.2
12.0
28.2
6.5
63.1
32.4
141.
89.1
151.
17.8
5.6
16.2
102.
95.5
97.7
81.3
70.8
35.5
38.9
56.2
36.3
10.5
56.2
33.9
4.5
120.
70.8
40.7
70.8
30.9
56.2
109
-------
CONCENTRATIONS OF INORGANIC, NONMETALLIC
POLLUTANTS - RUN 9, JULY 23, 1973. (Continued)
Sample
Position
301
303
305
3073
309a
311a
313
315
317
319
321a
323
501
503
505
507a
509a
511a
513a
515a
517a
5l9a
521
52 3a
525
601
602a
603
604
605
606
607
608
609
611
612
613
614a
615
617
618a
Rainfall
cm
0.66
0.86
0.34
0.44
0.48
0.46
0.42
0.55
0.46
0.30
0.40
1.07
0.51
0.29
0.18
0.33
0.54
0.68
0.61
0.66
0.54
0.62
0.26
0.31
0.71
0.80
0.70
0.69
0.91
1.14
1.21
0.74
0.78
0.70
0.67
0.63
0.68
0.70
0.66
0.70
0.71
Concentration (gm-moles/1) x 10
so2
0.36
<.2
<.2
0.64
0.52
1.95
<.2
<.2
<.2
<.2
0.38
<.2
1.14
<.2
2.37
0.99
0.41
0.36
2.49
0.40
0.47
<.2
0.36
<.2
0.25
0.24
0.69
0.32
<.2
<.2
0.64
<.2
<.2
0.34
0.60
0.37
0.22
<.2
so4=
43.6
34.9
45.6
50.4
90.2
52.2
37.5
26.9
31.5
44.2
46.1
45.7
21.4
49.7
53.7
53.1
52.3
49.3
73.9
66.8
32.2
18.8
32.7
41.1
27.9
27.1
22.4
21.5
40.7
22.5
24.8
44.0
38.7
31.1
76.7
46.4
N02
0.67
0.09
<.06
0.06
0.70
0.06
0.07
0.07
0.07
0.42
0.13
<.06
<.06
0.84
0.76
0.95
0.52
0.34
0.14
0.08
0.77
0.13
0.06
0.89
<.06
<.06
<.06
<.06
<.06
0.12
0.08
<.06
<.06
0.13
0.17
0.59
0.15
0.21
0.17
0.11
0.08
N03
44.9
35.7
58.1
45.7
53.3
18.3
43.9
51.9
50.7
71.4
58.8
31.4
55.4
90.5
74.0
51.2
88.1
171.
45.0
89.1
78.0
69.8
63.3
75.3
40.1
32.7
62.5
42.3
35.8
26.5
31.8
59.1
21.9
42.2
47.8
58.3
34.3
37.8
50.0
62.1
32.9
NH.+
4
14.3
11.0
21.0
24.2
12.5
32.9
25.7
16.3
15.1
13.2
13.4
9.2
13.6
3.1
10.6
14.5
50.9
56.3
9.6
25.9
48.0
10.2
18.2
29.7
18.2
11.8
7.7
10.3
18.8
14.6
17.4
14.1
8.1
9.6
9.6
5.7
4.8
14.8
11.8
17.3
6.5
H+
35.5
14.8
63.0
105.
35.5
77.6
81.3
70.8
56.2
43.7
10.2
30.9
148.
105.
37.2
19.5
31.6
14.1
123.
115.
33.1
120.
126.
2.5
95.5
22.4
95.5
120.
81.3
47.9
81.3
81.3
120.
34.7
63.1
41.7
17.8
3.5
63.1
56.2
60.3
110
-------
CONCENTRATIONS OF INORGANIC, NONMETALLIC
POLLUTANTS - RUN 9, JULY 23, 1973
(Continued)
Sample
Position
703
704
705
706
707
708a
710
714
715
716
Rainfall
cm
0.39
0.45
0.45
0.51
0.53
0.59
0.71
0.53
0.54
0.40
Concentration (gm-moles/1) x 10
so2
<.2
<.2
0.24
0.21
0.34
<.2
<.2
<.2
SV
66.7
46.4
46.4
89.6
67.7
78.1
46.2
51.0
N02
0.07
0.45
0.41
0.58
0.09
0.72
0.63
0.56
0.06
0.17
N03
64.7
34.7
38.0
41.1
32.4
49.7
51.0
41.4
35.0
50.2
NH.+
4
3.8
2.2
3.1
4.3
7.8
5.7
8.9
2.5
3.0
2.5
H+
66.1
79.4
77.6
20.9
14.1
21.9
14.1
35.5
70.8
77.6
111
-------
CONCENTEATIONS OF INORGANIC, NONMETALLIC
POLLUTANTS - RUN 10, JULY 23, 1973.
Sample
Position
007
0093
010
Oil
012
013
014
016
017
018
019
020
120
104
106
108
110
112
114
116
118
120
122
124
201
203
205
207
209
211
213a
2153
217
219
221a
223
225
Rainfall
cm
1.62
1.57
b
1.62
b
1.46
b
1.54
1.56
1.52
1.47
1.49
2.7
2.0
1.51
3.1
2.4
1.56
3.8
3.1
2.4
0.97
2.0
2.4
b
0.64
0.37
0.16
0.61
0.50
1.15
1.50
0.55
1.54
1.34
b
Concentration (gm-moles/1) x 10
so2
<.2
0.98
0.31
<.2
<.2
<.2
<.2
<.2
0.22
<.2
<.2
<.2
<.l
<.l
<.l
<.l
<.l
<.l
<.l
<.l
<.l
<.l
<.l
<. 1
<. 1
<.l
<. 1
<.l
<.l
<.l
<.l
<. 1
<.l
<.l
<.l
<.l
<.l
so4=
60.0
34.0
38.3
41.5
18.9
24.5
20.0
9.7
16.1
20.3
36.0
24.5
27.4
27.2
29.1
45.7
67.2
42.4
32.2
48.8
53.6
59.8
41.6
31.2
28.4
86.7
99.7
209.
56.6
108.
44.7
57.6
90.2
40.8
38.6
26.0
N02
0.09
0.29
0.19
0.08
0.07
<.06
0.08
<.06
<.06
<.06
<.06
<.06
<.06
<.06
<.06
<.06
<.06
<.06
<.06
<.06
<.06
<.06
<.06
<,06
<.06
<.06
<.06
0.10
0.11
0.07
0.07
<.06
<.06
0.08
<.06
<.06
0.08
N03
31.4
11.7
25.1
17.8
16.0
28.1
13.0
9.9
10.8
18.7
25.0
26.9
6.9
7.2
13.3
19.0
16.7
19.9
16.1
26.1
27.0
24.9
24.0
20.3
2.4
10.4
46.3
60.9
21.4
34.9
52.7
19.6
41.5
32.2
30.5
20.3
26.1
NH.+
4
29.6
25.5
29.8
24.2
21.6
21.6
22.5
13.9
11.6
23.3
28.3
20.1
7.3
9.8
14.0
21.2
9.8
17.1
22.0
22.3
19.9
15.8
20.2
10.5
14.3
15.1
18.1
21.8
12.8
42.8
26.3
16.3
24.1
31.9
15.1
18.1
13.2
H+
79.4
6.9
5.4
43.7
41.7
38.0
58.9
35.5
17.8
25.1
102.
64.6
38.9
61.7
83.2
105.
151.
123.
87.1
105.
186.
102.
57.5
46.8
126.
117.
97.7
50.1
77.6
120.
112.
120.
132.
89.1
93.3
37.2
112
-------
CONCENTRATIONS OF INORGANIC, NONMETALLIC
POLLUTANTS - RUN 10, JULY 23, 1973. (Continued)
Sample
Position
301
303
305
307
315
319
321
323
501
503
505
507
523
525
601a
602
603
604
605
606
607
615
701
702
703
704
705
708
710
711
713
714
715
716
Rainfall
cm
1.53
1.28
1.09
0.63
0.15
0.45
0.69
1.51
0.87
0.19
0.16
0.17
0.17
0.25
0.43
0.63
0.37
1.24
0.49
0.37
0.52
1.16
b
b
2.6
2.6
1.40
1.8
1.48
0.91
2.7
b
b
b
Concentration (gin-moles /I) x 10
so2
1.52
<.2
<.2
0.32
0.22
0.24
<.2
<.2
0.38
<.2
<.2
0.24
<.2
S°4=
88.4
94.0
52.6
50.0
32.1
65.5
83.3
30.8
61.1
18.4
24.5
71.9
65.6
50.4
67.1
60.4
41.0
30.2
107.
22.9
30.2
15.7
35.4
59.4
62.5
74.0
67.7
80.2
43.8
27.1
21.9
N02
0.73
0.13
0.07
<.06
<.06
0.06
0.14
<.06
0.06
<.06
0.08
0.08
0.07
<.06
0.12
<.06
0.07
<.06
<.06
0.07
0.07
<.06
0.12
<.06
0.06
<.06
0.09
<.06
0.07
<.06
<.06
<.06
N03
47.1
55.5
77.4
24.8
36.1
47.9
31.6
27.7
42.5
55.1
39.2
31.8
42.2
35.0
13.8
31.6
30.1
32.5
30.8
23.2
7.2
15.5
8.9
12.5
20.4
23.8
26.5
31.6
15.9
12.2
8.0
8.5
NH4+
29.2
32.5
21.5
35.8
18.4
16.7
19.9
19.3
13.1
16.5
46.9
21.6
22.6
18.8
16.9
11.0
16.0
20.4
17.4
18.6
19.3
16.0
8.3
9.9
13.5
15.3
23.3
23.5
20.0
21.9
14.2
10.1
9.4
H+
38.9
102.
129.
123.
51.3
132.
224.
75.9
112.
112.
75.9
56.2
69.2
77.6
250.
288.
145.
191.
158.
178.
151.
77.6
37.2
20.9
39.8
38.9
100.
95.5
20.0
126.
12.3
57.5
47.9
26.3
Questionable quality - see text.
Sampler overflowed. Will be estimated later from raingage records,
113
-------
SEQUENTIAL SAMPLE CONCENTRATIONS OF INORGANIC,
NONMETALLIC POLLUTANTS - RUN 10, JULY 23, 1973.
Sample
Position
(Sequential)
301-0
P
Q
R
S
T
U
V
Rainfall
Rate
cm/hr
2.15
0.57
2.66
1.54
2.81
0.93
0.12
0.31
Concentration (gm-moles/1) x 10
so2
<.l
<.l
<.l
<.l
<.l
<.l
<.l
<.l
so4=
95.8
144.
99.0
70.8
97.9
115.
144.
148.
N02
0.07
0.07
0.07
0.07
.06
.06
.06
0.10
N03
29.8
49.0
30.5
27.2
28.3
35.3
49.3
80.1
NH.+
4
36.8
68.0
41.7
26.7
24.0
29.6
44.1
45.9
H+
126.
20.4
117.
141.
158.
204.
407.
407.
114
-------
CONCENTRATIONS OF INORGANIC, NONMETALLIC
POLLUTANTS - RUN 11, JULY 24, 1973.
Sample
Position
303
305
707
708
Rainfall
cm
1.59
0.53
0.27
1.56
Concentration (gm-moles/1) x 10
so2
0.22
<.2
<.2
<.2
s<>4=
72.6
62.4
135.
92.0
N02
0.06
.06
0.20
0.10
N03
50.8
50.6
162.
77.8
NH.+
4
30.8
23.7
66.8
52.2
H+
123.
178.
158.
178.
115
-------
CONCENTRATIONS OF INORGANIC, NONMETALLIC
POLLUTANTS - RUN 12, JULY 25, 1973.
Sample
Position
317
319
321
405
419
427
509
511
513
515
517
519
521
606a
Rainfall
cm
0.12
0.40
0.25
0.16
0.16
0.27
0.67
0.38
0.23
0.19
0.13
0.62
0.19
0.62
Concentration (gm-moles/1) x 10
so2
<.l
0.26
0.61
<.l
<.l
<.l
<.l
<.l
SV
91.0
60.4
101.
105.
40.6
96.5
20.7
38.8
73.2
64.4
109.
18.3
35.8
106.
N02
<.06
0.08
0.13
0.10
<.06
<.06
<.06
N03
52.8
44.9
58.7
72.2
34.6
47.3
19.0
20.9
36.1
28.3
45.7
15.9
32.4
49.6
NH.+
4
14.9
9.3
18.5
11.6
36.7
12.9
24.2
12.9
11.8
12.4
16.7
16.4
55.1
17.0
H+
79.4
155.
49.0
41.7
51.3
3.5
60.3
93.3
151.
120.
16.6
89.1
66.1
151.
116
-------
CONCENTRATIONS OF INORGANIC, NONMETALLIC
POLLUTANTS - RUN 13, JULY 25, 1973.
Sample
Position
(Sequential)
200-A
B
C
D
E
F
G
H
Rainfall
Rate
cm/hr
1.07
0.26
0.24
0.80
0.73
0.26
0.30
0.37
Concentration (gin-moles /I) x 10
S02
3.25
2.46
4.52
2.24
3.19
3.88
1.74
4.28
so4-
68.8
58.3
26.0
83.3
41.7
36.5
36.5
N02
<.06
<.06
<.06
<.06
<.06
<.06
<.06
N03
30.3
29.1
14.7
24.7
12.2
10.4
13.0
6.7
NH4+
24.3
5.5
5.3
9.5
4.6
3.6
6.0
1.2
H+
126.
245.
126.
162.
132.
120.
126.
95.5
117
-------
CONCENTRATIONS OF INORGANIC NONMETALLIC
POLLUTANTS - RUN 14, JULY 25-26, 1973.
Sample
Position
007
008
oioa
Oil
012
013
014
015
016
017
018
019
020
022
102a
104a
106a
108a
110a
112a
114
Il6a
118a
124a
201
205
209
213
215
217
223
225
309
311
313
315
317
Rainfall
cm
0.44
0.21
0.20
0.23
0.37
0.57
0.85
1.33
b
b
b
1.18
1.34
0.68
b
b
b
1.55
0.81
1.04
b
0.88
1.36
1.18
0.20
0.31
0.53
0.57
1.26
0.51
0.62
1.30
0.43
0.87
0.57
1.00 •
Concentration (gm-moles/1) x 10
so2
<.2
0.99
<.2
0.21
<.2
<.2
0.56
0.24
0.35
<.2
<.2
<.2
<.2
<.2
<.2
<.2
0.30
0.78
1.09
0.48
<.2
0.82
0.26
0.31
0.82
0.55
0.78
1.07
0.26
0.31
<.2
0.29
<.2
<.2
0.26
<.2
so4=
24.5
46.8
29.2
38.5
23.0
47.9
29.5
14.7
12.5
27.1
13.5
18.8
43.6
27.1
73.0
55.2
89.4
83.3
63.5
64.9
95.8
57.3
73.7
75.3
67.5
63.3
45.7
59.2
51.8
64.5
80.1
22.7
32.8
47.5
35.5
N02
0.06
0.07
<.06
0.19
0.06
0.07
0.07
<.06
<.06
<.06
<.06
<.06
<.06
<.06
<.06
<.06
<.06
0.13
0.10
0.10
0.06
0.06
0.06
0.11
0.52
0.10
<.06
<.06
0.14
0.07
<.06
<.06
<.06
<.06
<.06
<.06
<.06
N03
17.3
33.0
21.2
23.1
8.2
9.0
21.0
15.0
5.1
5.5
4.5
4.5
7.6
14.8
10.5
25.3
42.6
79.1
75.7
54.1
35.3
53.3
35.5
29.1
30.7
38.5
44.9
28.8
28.9
28.2
24.9
31.6
10.8
21.8
26.1
15.3
NH4+
14.0
21.8
15.7
14.5
8.2
8.2
8.5
7.2
5.5
7.7
5.1
7.5
7.7
9.0
10.8
8.0
16.5
26.5
29.9
26.3
18.6
18.6
19.1
14.5
11.4
15.0
22.4
29.1
15.2
13.7
11.0
11.0
29.3
9.0
17.2
25.9
15.2
H+
25.7
1.4
38.0
3.9
19.1
35.5
46.8
40.7
31.6
30.9
19.5
28.2
38.9
9.5
51.3
57.5
174.
251.
64.6
324.
389.
158.
355.
120.
5.6
66.1
75.9
112.
100.
126.
141.
186.
162.
126.
112.
52.5
97.7
118
-------
CONCENTRATIONS OF INORGANIC NONMETALLIC
POLLUTANTS - RUN 14, JULY 25-26, 1973.
(Continued)
Sample
Position
601
602
603
604
605a
607a
608
609
610
611
618
701
702
703
704
705
706
707
708
714
715
716
Rainfall
cm
0.11
0.07
0.12
0.16
0.17
0.29
0.25
0.18
0.16
0.16
0.31
b
1.17
0.80
0.71
0.43
0.26
0.12
0.11
0.56
0.84
1.14
Concentration (gm-moles/1) x 10
so2
<.2
<.2
<.2
<.2
0.30
4.71
1.75
0.43
0.21
1.25
.18
0.89
so4=
40.6
47.9
46.9
31.3
28.1
26.0
28.1
25.0
63.5
28.1
35.9
53.3
59.5
57.2
50.2
92.8
136.
61.8
44.2
60.6
N02
0.07
0.07
0.07
0.09
0.30
<.06
0.10
<.06
<.06
<.06
0.10
<.06
<.06
0.10
N03
19.5
32.8
16.1
17.1
22.6
24.7
20.6
13.4
18.8
22.9
27.2
55.3
22.8
30.0
45.8
29.8
20.9
26.7
NH4+
15.7
12.7
18.3
15.0
13.4
14.5
6.0
18.8
9.5
12.9
14.0
16.4
14.8
10.0
19.2
21.7
11.8
12.3
9.6
H+
38.0
55.0
36.3
57.5
23.4
46.8
83.2
69.2
0.5
15.5
7.1
44.7
97.7
93.3
95.5
29.5
3.2
1.0
1.0
25.1
87.1
112.
Questionable quality - see text.
Sampler overflowed. Will be estimated later from raingage records.
119
-------
does not harm the measurements for all but S0~. Thus the overnight samples
may be more useful than we had thought earlier. Some changes in concentra-
tion appear to occur with time, but these at present do not seem to be in
any particular pattern or due to any recognized cause.
Aircraft Sampling
Through cooperation with concurrent field activities, we were able to col-
lect significant airborne measurements of pollutants. Approximately half
the field time period was allocated for pollutant gas and particle size
distribution measurements, and the other half for tracer releases for the
AEC-sponsored METROMEX Tracer Scavenging program. Unfortunately, the for-
mer period was characterized by fair weather, so our measurements did not
directly relate to precipitation-sampled storms. During the latter period,
on non-storm days, high-volume air samples were taken. These will be
analyzed for inorganic pollutant content.
The most notable achievement of the aircraft sampling in support of this
project was the successful aircraft operation of a chemiluminescent NO-NO
X
monitor. Vertical profiles of NO-NO content were flown on several occas-
ions, upwind, downwind, and over the city. These were timed for close
coordination with ground-level measurements using the same type of instru-
ment. These latter were done by researchers of Battelle, Columbus, who
were based at St. Louis University in downtown St. Louis. The data are in
the process of analysis and interpretation, but it has been found that the
concentrations of both NO and NO at 1500 ft MSL were higher than those at
X
the ground. The nitrogen oxides levels then decreased with height above
1500 feet.
120
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APPENDIX B: SOME REFERENCES PERTINENT TO THE FIELD
OF PRECIPITATION CHEMISTRY
As noted in Table 2, virtually no direct information is available regard-
ing airborne chemical transformations significant to scavenging within
the St. Louis field-experiment system. Because of the embryonic state
of knowledge of this subject, we have compiled a brief review of precipi-
tation chemistry to provide some basis for practical application and
further research in the field.
The references included here are by no means a complete listing of arti-
cles covering all aspects of precipitation chemistry. Notably missing,
for instance, is the significant number of articles pertaining to contri-
butions in the areas of biological and surface response. These have been
omitted for brevity and because they have only an indirect relationship
with the atmospheric removal and transformation processes of primary con-
cern in this work.
Early portions of the reference listing are itemized according to posi-
tions of specific elements on the periodic chart. Other more general
categories are included in the later portions to contain multiple cate-
gories (metals, nonmetallic inorganics, organics, inorganics, and "general")
Articles within each category are listed in alphabetical order of the
names of the first authors.
GROUP I - Elements H, Li, Na, K, Rb, Cs
1. Barrett, E. and G. Brodin. The Acidity of Scandinavian Precipitation.
Tellus. 7:251-257, 1955.
2. Hogan, Austin W. and T. A. Rich. Mobile Tracing Technique Utilizing
a Meteorologically Inert Lithium Aerosol. Atmos. Sci. Res. Center.
State University of New York, Albany, N.Y.
3. Likens, G. E. and F. H. Bormann and N. M. Johnson. Acid Rain.
Environment. 1A:33-40, 1972.
4. Moghissi, A. Alan, and Charles R. Porter. Tritium Concentration in
Precipitation. Radiol. Health Data Rep. 11:137-40, 1970.
121
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5. Nyberg, Alf. Weather Changes Important for the Acidity of Rainfall.
Forsk. Framsteg. 1:18-21, 1970.
6. Warburton, J. A. and L. G. Young. Neutron Activation Measurements of
Silver in Precipitation from Locations in Western North America. J.
Appl. Meteorol. 7:444-448, 1968.
GROUP II - Elements Be, Mg, Ca, Zn, Sr, Cd, Ba, Hg, Ra
GROUP III - Elements B, Al, Sc, Ga, Y, In
GROUP IV - Elements C, Si, Ti, Ge, Zr, Sn, Hf, Pb
1. Atkins, Patrick R. Lead in a Suburban Environment. J. Air Pollut.
Contr. Assoc. 19:591-594, 1969.
2. Francis, Chester W., Gordon Chesters, and Larry A. Haskin. Determina-
tion of Lead-210—Mean Residence Time. Environ. Sci. Technol.
4:586-589, 1970.
3. Galbally, I. E. Production of Carbon Monoxide in Rainwatrr. J. Geo-
phys. Res. 77:7129-7132, 1972.
4. Lazrus, Allan L., Elizabeth Lorange, and James P. Lodge, Jr. Lead and
Other Metal Ions in United States Precipitation. Environ. Sci. Technol.
4:55-58, 1970.
5. Preobrazhenskaya, E. V. Measurements of the Lead Concentration in
Rainfall During its Natural Fallout and During the Action of Lead
Iodide on the Clouds. Tr. Gl. Geofiz. Observ. 239:43-48, 1969.
GROUP V - Elements N, P, V, As, Cb, Sb, Ta, Bi
1. Angstrom, A. and L. Hbgberg. On the Content of Nitrogen in Atmospher-
ic Precipitation. Tellus. 4:31-42, 1952.
2. Burtsev, I. I., L. V. Bertseva, and S. G. Malakhov. Washout Character-
istics of Phosphorus-32 Aerosols Injected into Clouds. Issled. Protses-
sov Samoochishcheniya Atmos. Radioaktiv. Izotop. Sb. Dokl., Soveshch.
335-345, 1966. Pub. 1968.
3. Commoner, Barry. Threats to the Integrity of the Nitrogen Cycle.
Nitrogen Compounds in Soil, Water, Atmosphere, and Precipitation. Glo-
bal Eff. Environ. Pollut. Symp. 70-95, 1968, Pub. 1970.
4. Drover, D. P. and I. P. Barrett-Lennard. Accessions of Nitrogen in
Western Australian Wheat Belt Rains. J. Aust. Agric. Sci. 22:193-197,
1956.
122
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5. Eriksson, E. Composition of Atmospheric Precipitation I. Nitrogen
Compounds. Tellus. 4:215-233, 1952.
6. Gosz, James R. Sources of Nitrogen in Precipitation and Sedimenta-
tion Near Moscow, Idaho. Avail. University Microfilms, Ann Arbor,
Mich. Order No. 70-10, 701. 85 p. 1969. From Diss. Abstr. Int.
B 1970. 30(12) Pt. 1, 5312.
7. Jones, M. J. Ammonium and Nitrate Nitrogen in the Rainwater at
Samaru, Nigeria. Tellus. 23: 459-461, 1971.
8. Junge, C. E. The Distribution of Ammonia and Nitrate in Rainwater
Over the United States. Trans. A.G.U. 39:241-248, 1958.
9. Lavrinenko, R. F. Amount of Nitrogen Compounds in Precipitation
During Storms. Tr. Gl. Geofiz. Observ. (Russ) No. 234, 205-207,
1968.
10. McConnell, J. C. Atmospheric Ammonia. J. Geophys. Res. 78:7812-
7821, 1973.
11. Meyer, J. and E. Pampher. Nitrogen Content of Rainwater Collected
in the Humid Central Congo Region. Nature. 184:717-718, 1959.
12. Nucciotti, F. and N. Rossi. Chemical Composition of Atmospheric
Precipitation in Emilia II. Nitrous, nitric, and ammoniacal nitrogen
and phosphorus. Agrochimica. 12:536-544, 1968. (Ital.)
13. Popovsky, Jiri. Phosphorus, Arsenic, and Germanium Compounds in
Rain Water. Vod. Hospod. 18:24-26, 1968. (Czech.)
14. Reiter, R. Further Experimental Evidence for the Importance, With
Respect to Thunderstorm Electrification, of Nitrate Ions Contained
in Precipitation. II. J. Atmos. Terr. Phys. 30:345-362, 1968.
15. Scharrer, K. and H. Fast. Investigations of Plant Nutrients Supplied
to Soil in Precipitation. A. PflErnahr. Diing. 55:97-106, 1951.
16. Shilina, L. I. Introduction of Nitrogen into Soils by Means of
Atmospheric Precipitation and Its Extraction with Lysimetric Water.
Zemlerobstvo, Respub. Mizhvidom. Temat. Nauk. Zb. 2:102-106, 1967.
17. Syers, J. K. The Relationship Between the Concentration of Nitrate
and Ammonia Nitrogen in Precipitation. Tellus. 28:146-147, 1966.
18. Tarrant, R. F., K. C. Lu, C. S. Chen, and W. B. Bollen. Nitrogen
Content of Precipitation in a Coastal Oregon Forest Opening. Tellus.
20:554-556, 1968.
123
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19. Tsunogai, Shizuo. Ammonia in the Oceanic Atmosphere and the Cycle of
Nitrogen Compounds Through the Atmosphere and Hydrosphere. Geochem.
J. 5:57-67, 1971.
20. Viemeister, P. E. Lightning and the Origin of Nitrates Fonnd in
Precipitation. J. Meteorol. 17:68,-683, 1960.
21. Virtanen, A. J. Molecular Nitrogen Fixation and Nitrogen Cycle in
Nature. Tellus. 4:304-306, 1952.
22. Weinmann, H. The Nitrogen Content of Rainwater in Southern Rhodesia.
S. Afr. J. Sci. 52:82-84, 1955.
23. Wetselaar, R. and J. T. Button. The Ionic Composition of Rainwater at
Katherine, N. T. and Its Part in the Cycling of Plant Nutrients.
Aust. J. Agr. Res. 14:319-329, 1963.
24. Yaalon, D. H. The Concentration of Ammonia and Nitrate in Rainwater
Over Israel in Relation to Environmental Factors. Tellus. 16:200-
204, 1964.
GROUP VI - Elements 0, S, Cr, Se, Mo, Te, W, Po
1. Barrow, N. J., Keith Spencer, and W. M. McArthur. Effects of Rainfall
and Parent Material on the Ability of Soils to Adsorb Sulfate. Soil
Sci. 108:120-126, 1969.
2. Bassett, H. and W. G. Parker. Oxidation of Sulfurous Acid. J. Chem.
Soc. 1540-1560, 1951.
3. Beilke, S. and H. GeorgLi, Investigation on the Incorporation of
Sulfur Dioxide into Fog and Rain Droplets. Tellus. 20:435-441,
1967.
4. Beilke, S., D. Lamb, and J. Miller. Neure Untersuchungen zur Oxida-
tion von Schwefeldioxid in Gegenwart von Flilssigwasser. Report,
Universitat-Institute fur Meteorologie und Geophysik, Frankfurt/Main,
Germany.
5. Cheng, R. T., M. Corn, and J. 0. Frohliger. Contribution to the
Reaction Kinetics of Water Soluble Aerosols and S02 in Air at PPM
Concentrations. Atm. Env. 5:987-1008, 1971.
6. Cortecci, G. and Antonio Longinelli. Isotopic Composition of Sulfate
in Rain Water, Pisa, Italy. Earth Planet Sci. Lett. 8:36-40, 1970.
7. Dana, M. Terry, J. M. Hales, and M. A. Wolf. Natural Precipitation
Washout of Sulfur Compounds from Plumes. Final Report to the Environ-
mental Protection Agency, Raleigh, NC. Publication No. R3-73-047.
1973. 202 p.
124
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8. Eriksson, E. The Yearly Circulation of Sulfur in Nature. Jour.
Geophys. Res. 68:4001-4008, 1963.
9. Fuller, E. C. and R. H. Christ. The Rate of Oxidation of Sulfite
Ions by Oxygen. J. Am. Chem. Soc. 63:1644-1650, 1941.
10. Gallagher, P. A. Effect of Sulfur in Fertilizers, Rainwater, and
Aoila on Crop Nutrition. Sci. Proc. Roy. Dublin Soc., Ser. B 2:
191-204, 1969.
11. Georgii, H. W., Contribution to the Atmospheric Sulfur Budget.
J. Geoph. Res. 75:2365-2371, 1970.
12. Georgii, H. W. On the Effect of Rainfall on the S02 Concentration
in the Atmosphere. Int. J. Air Wat. Poll. 7:1057-1059, 1963.
13. Gerhard, E. R. and H. F. Johnstone. The Photochemical Oxidation
of Sulfur Dioxide to Sulfur Trioxide and Its Effect on Fog Forma-
tion. Ind. Eng. Chem. 47:972-976, 1965.
14. Granat, L. and H. Rodhe. A Study of Fallout by Precipitation
Around an Oil Fired Power Plant. Atmos. Env. 7, 781-792, 1973.
15. Hales, J. M. and S. L. Sutter. Solubility of Sulfur Dioxide in
Water at Low Concentrations. Atm. Envi. 7:997-1001, 1973.
16. Hales, J. M., J. M. Thorp, and M. A. Wolf. Field Investigation of
Sulfur Dioxide Washout from the Plume of a Large Coal-Fired Power
Plant. Final Report to Environmental Protection Agency. Publica-
tion Number BNW-389, 1971.
17. Hanley, P. K. and S. L. Tierney. Sulfur Studies. I. Contribution
of Sulfur in Precipitation to Crop Production in Ireland. Irish
J. Agr. Res. 8:19-27, 1969.
18. Hashimoto, Yoshikazu and John W. Winchester. Selenium in the
Atmosphere. Environ. Sci. Technol. 1:338-340, 1967.
19. Hoather, R. C. and C. F. Goodeve. The Oxidation of Sulfurous Acid.
Trans. Far. Soc. 30:1149-1156, 1934.
20. Hutcheson, M. R. and F. P. Hall. Sulfate Washout from a Coal-Fired
Power Plant Plume. Atm. Envi. (in Press).
21. Johnstone, H. F. and D. R. Coughanowr. Absorption of Sulfur
Dioxide from Air. I and E.G. 50:1169, 1958.
22. Johnstone, H. F. and A. J. Moll. Formation of Sulfuric Acid in
Fogs. I and E.G. 52:861, 1960.
125
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23. Junge, C. E. Sulfur in the Atmosphere. J. Geoph. Res. 65:227-237,
1960.
24. Junge, C. E. and T. G. Ryan. The Oxidation of Sulfur Dioxide in
Dilute Solutions. Quart. J. Roy. Met. Soc. 84:46-55, 1958.
25. Lavrinenko, R. F. Sulfur Content in Rainfall. Tr. Gl. Geofiz.
Observ. 207:87-91, 1968.
26. Matteson, M. J., W. Stueber, and H. Luther. Kinetics of the Oxida-
tion of Sulfur Dioxide by Aerosols of Manganese Sulfate. I and E.G.
Fund 8:677-687, 1969.
27. McKay, H. A. The Oxidation of Sulphur Dioxide in Water Droplets in
the Presence of Ammonia. Atm. Envi. 5:7-14, 1971.
28. Miller, J. M. A Model for the Rainout and Washout of Sulfates in the
Atmosphere. Penn. State University Center for Air Environment Studies
Pub. No. 239-72, 1972.
29. Miller, J. M. and R. G. dePena. Contribution of Scavenged Sulfur
Dioxide to the Sulfate Content of Rainwater. J. Geophys. Res.
77:5905-5916, 1972.
30. Miller, J. M. and R. G. dePena. The Rate of Sulfate Ion Formation in
Water Droplets in Atmospheres with Different Partial Pressures of
S02- In: Proc. 2nd Int. Clean Air Congress, Washington, DC,
Dec. 6-11, 1970.
31. Mizutani, Yoshihiko, and T. Atho Rafter. Oxygen Isotopic Composition
of Sulfates. V. Isotopic Composition of Sulfate in Rain Water,
Gracefield, New Zealand. N. Z. J. Sci. 12:69-80, 1969.
32. Penkett, S. A. Oxidation of S02 and Other Atmospheric Gases by Ozone
in Aqueous Solution. Nature Phys. Sci. 240:55-106, 1972.
33. Rodhe, Henning. Residence Time of Anthropogenic Sulfur in the Atmos-
phere. Tellus. 22:137-139, 1970.
34. Rodhe, Henning. A Study of the Sulfur Budget Over Northern Europe.
Tellus. 24:128-135, 1972
35. Rodhe, Henning. A Study of the Sulfur Budget for the Atmosphere Over
Northern Europe. Final Report AC-17 International Meteorological
Institute (Stockholm). 1971.
36. Scott, W. D. and P. V. Hobbs. The Formation of Sulfate in Water
Droplets. J. Atmos. Sci. 24:54-57, 1967.
126
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37. Shaw, R. W. and D. M. Welpdale. Sulfate Deposition by Precipitation
in Lake Ontario. Water, Air, Soil Pollut. 2:125-128, 1973.
38. Simmers, P. W. Scavenging of SC>2 by Convective Storms. In:
Precipitation Scavenging. USAEC Conf 700601, 1970.
39. Sweden's Case Study Contribution to the United Nations Conference on
the Human Environment. Royal Ministry of Foreign Affairs, Royal
Ministry of Agriculture, 1971.
40. Val'nikov, I. U. Amount of Sulfur Depositing on the Earth's Surface
with the Atmospheric Precipitation in Tatar SSR. Biol. Nauki.
14:110-111, 1971.
41. Val'nikov, I. U. Sulfur Turnover and Its Importance for Crop Produc-
tion in Tatar ASSR. Pochvovedenie. 3:40-47, 1971.
42. Van Den Heuvel, A. P. and B. J. Mason. The Formation of Ammonium
Sulfate in Water Droplets Exposed to Gaseous Sulfur Dioxide and
Ammonia. Q. J. Roy. Met. Soc. 89:271-275, 1963.
43. Walker, D. R. Sulfur in Precipitation in Central Alberta. Can. J.
Soil Sci. 49:409-410, 1969.
44. Witt, Ernst. Lethal Effect of Exhaust Gases on the Water Fauna.
Zentralbl. Arbeitsmed. Arbeitsschutz. 19:264-265, 1969.
GROUP VII - Elements F, Cl, Mn, Br, Te, I, Re, At
1. Chamberlain, A. C. and R. C. Chadwick. Transport of Iodine from
Atmosphere to Ground. Tellus. 18:226-237, 1966.
2. Duce, Robert A., John W. Winchester, and Theodore W. van Nahl.
Iodine, Bromine, and Chlorine in Winter Aerosols and Snow From
Barrow, Alaska. Tellus. 18:238-248, 1966.
3. Garber, Kurt. Fluoride in Rain Water and Vegetation. Fluoride
Quart. Rep. 3:22-26, 1970.
4. Harriss, Robert C. and Harold H. Williams. Specific-ion Electrode
Measurements on Bromine, Chlorine, and Fluorine in Atmospheric
Precipitation. J. Appl. Meteorol. 8:299-301, 1969.
5. Inoue, Tomoo and Jishin Kobayashi. Distribution of Chloride in
Rain Water and Land Forms in the Northern Tohoku District. Shigen
Kagaku Kenkyusho Iho. 75:73-80, 1971.
6. Shmeter, S. M. On the Content of Chloride in Cloud Water in
Connection with Fine-Scale Structure. Trudy ZAO. 9, 1952.
127
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7. Svistov, P. F. and E. S. Selezneva. Some Data on Chemical Composition
and Distribution of Aerosols on the Kola Peninsula Coast. Tr. Gl.
Geofiz. Observ. 185:116-116, 1966. (Russ)
8. Valach, R. The Origin of the Gaseous Form of Natural Atmospheric
Chlorine. Tellus. 19:509-516, 1967.
9. Valach, Roman. Fluoride and Chloride in Precipitation of Bohemia.
Stud. Geophys. Geod. Cesk. Akad. Ved. 11:241-251, 1967.
10. Zerche, M. and W. Haensch. Determination of the Chloride Content of
Precipitation in the Schwerin/Mecklenburg Area. Z. Meteorol.
19:97-101, 1967.
GROUP VIII - Elements Fe, Co, Ru, Rh, Os, Ir
GROUP 0 - Noble Gases
1. Loosli, H. H., Hans Oeschger, and W. Wiest. Argon-37, Argon-39, and
Krypton-81 in the Atmosphere and Tracer Studies Based on These Isotopes,
J. Geophys. Res. 75:2895-2900, 1970.
METALS
1. Belyaev, L. I. and E. I. Ovsyanyi. Trace Elements in Atmospheric
Precipitation in a Coastal Region in Relation to Some Problems of
Chemical Oceanography. Gidrokhim. Mater. 51:3-12, 1969. (Russ).
2. Bogdanova, L. L. Role of the Composition of Atmospheric Precipitation
in the Formation of Fracture Waters in Weathering Profiles of the
Transbaikalia Mountain Structures. Form. Geokhim. Podzemn. Vod Sib.
Dal'nego Vostoka. Inst. Zemnoi Kory Sib. Otd. Akad. Nauk SSSR 64-73,
1967. (Russ)
3. Drozdova, V. M. and E. P. Makhon'ko. Content of Trace Elements in
Precipitation. J. Geophys. Res. 75:3610-3612, 1970.
4. Drozdova, V. M. and P. F. Svistov. Trace Element Content in Rainfall.
Tr. Gl. Geofiz. Observ. 207:92-97, 1968. (Russ)
5. Garber, Kurt. Air Pollution by Heavy-Metal-Containing Dusts. Effects
on Plants. Landwirt. Forsch. Sonderh. 25:59-68, 1970. (Ger)
6. Hanappe, F., M. Vosters, E. Picciotto, and S. Deutsch. Chemistry of
Antarctic Snows and Deposition Rate of Extraterrestrial Matter. II.
Earth Planet Sci. Lett. 4:487-496, 1968.
128
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7. Lag, J. General Problems in Soil Chemistry in Relation to the
Chemical Composition of the Precipitation. Medlemsbl. Nor.
Veterinaerforen. 21:117-124, 1969. (Norweg)
8. Lazrus, A. L., E. Lorange, and J. P. Lodge. Lead and Other Metal
Ions in United States Precipitation. Env. Sci. Tech. 4:55-57,
1970.
9. Makhon'ko, E. P. and V. M. Drozdova. Trace Element Level in
Precipitation. Tr. Inst. Eksp. Meteorol. 14:81-85, 1971. (Russ)
10. Ragone, S. E. and C. A. Wolf. Analysis of the Major Cationic
Constituents of Dye Sites 2 and 3, Greenland. U. S. Nat. Techn.
Inform. Service. AD Rep. No. 743473, 1972. 13 p.
11. Steffe, Dirl H. Control of Contamination in Hail Samples Collected
for Trace Metal Analysis. J. Appl. Meteorol. 9:193-194, 1970.
12. Von Arx, U., V. Zeier, and M. Semlitsch. Microstructure Studies
on Magnetic Spheroids Found in Alpine Snow and Foundry Dust Samples
in Switzerland. Sulzer Tech. Rev. 52:268-274, 1970.
NONMETALLIC INORGANICS
1. Beilke, S. Research Concerning the Washout of Precipitation of
Atmospheric Elements. University of Frankfurt/Main, Germany.
Report APTIC TR-0701, 1970.
2. Eriksson, E. The Yearly Circulation of Chloride and Sulfur in the
Atmosphere, Part I. Tellus. 11:375-403, 1959.
3. Eriksson, E. The Yearly Circulation of Chloride and Sulfur in
Nature, Part II. Tellus. 11:375-403, 1959.
4. Garland, J. A., J. R. Branson, and L. C. Cox. Study of the Contri-
bution of Pollution to Visibility in a Radiation Fog. Atm. Env.
7:1079-1092, 1973.
5. Georgii, Hans W. Untersuchungen Uber Atmospharische Spurenstoffe
Und Ihre Bedeutung Fur Die Chemie der Niederschlage. Geofisica
Pura E Applicata. Bd. 47:155-171, 1960.
6. Georgii, Hans W. and Dieter Woetzel. Relation Between Drop Size
and Concentration of Trace Elements in Rain Water. J. Geophys.
Res. 75:1727-1731, 1970.
7. Hoeft, R. G., D. R. Keeney, and L. M. Walsh. Nitrogen and Sulfur
in Precipitation and Sulfur Dioxide in the Atmosphere in Wisconsin.
J. Environ. Qual. 1:203-208, 1972.
129
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8. Houghton, H. C. The Chemical Composition of Fog and Cloud Water.
Journ. of Meteorology. 12:355-357, 1955.
9. Leland, E. W. Nitrogen and Sulfur in the Precipitation at Ithica,
N. Y. Agron. J. 44:172-175, 1952.
10. Ludwig, F. L. and E. Robinson. Observation of Aerosols and Droplets
in California Stratus. Tellus. 23:163-170, 1971.
11. Mrose, H. Measurements of pH and Chemical Analyses of Rain-, Snow-,
and Fog-water. Tellus. 18:266-270, 1969.
12. Piskunov, L. I. Background and Anomalous Correlations of Chlorides
and Sulfates in Atmospheric Precipitation. Dokl. Akad. Nauk SSSR
193:1388-1391, 1970. (Russ)
ORGANICS
1. Atkins, D. H. F., and A. E. J. Eggleton. Studies of Atmospheric
Washout and Deposition of j-WC [y-benzene hexachloride], Dieldrin,
and pp-DDT Using Radiolabeled Pesticides. Nucl. Tech. Environ.
Pollut. Proc. Symp. 521-523, 1970.
2. Bakhanova, R. A., and E. G. Solyanek. Application of Surface-Active
Agents to Prevent Water Evaporation Fogs Over the Nonfreezing Water
Basins in Winter. Proc. Int. Conf. Cloud Phys. 688-693, 1968.
3. Bakhanova, R. A., E. G. Solyanek and F. S. Terziev. Method for
Producing Films of Surfactants from Highly Dispersed Aqueous Suspen-
sions of Higher Aliphasic Alcohols for Modifying the Vaporization
Fog. Tr. Vses. Konf. Fiz. Oblakov Aktiv. Vozdeistviyam, 8th.
319-324, 1969. (Russ)
4. Gernet, E. V., S. M. Gliklikh, M. N. Koshta and V. A. Fedoseev.
Feasibility of Fog Stabilization Using Surfactants. Mezhvuz. Konf.
Vop. Ispareniya, Goreniya Gazov. Din. Dispersynykh Sist., Mater.,
6th 4-9, 1966. (Publ. 1968, Russ)
5. Kuehne, Rudolf, Helmut Diery, and Siegbert Rittner. Fog-Eliminating
Agents. Ger. Offen. 2,016,705 28 Oct 1971, Appl. 08 Apr. 1970;
11 p.
6. Parker, Bruce C. Rain as a Source of Vitamin BI . Nature. 219:617-
618, 1968. i2
7. Semenov, A. D., L. I. Nemtsefa, T. S. Kishkinova and A. P. Pashanova.
Organic Substances of Atmospheric Precipitations. Dokl. Akad. Nauk
SSSR. 173:1185-1187, 1967. (Russ)
130
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8. Semenov, A. D. and T. S. Kishkinova. Carbonyl Compounds in Natural
Waters. Gidrokhim. Mater. 44:83-87, 1968. (Russ)
9. Sidle, Alan B. Amino Acid Content of Atmospheric Precipitation.
Tellus. 19:128-135, 1967.
10. Skopintsev, B. A., A. J. Bakulina and N. I. Mel'nikova. Total
Organic Carbon in Atmospheric Precipitations. Gidrokhim. Mater.
16:3-10, 1971.
11. Tarrant, K. R. and J. O'G. Tatton. Organochlorine Pesticides in
Rainwater in the British Isles. Nature. 219:725-727, 1968.
INORGANICS
1. Agarwal, V. . and G. P. Roy. Note on Plant Nutrients in Rainwater
at Varanasi. Indian J. Agr. Sci. 40:933-934, 1970.
2. Allen, Stewart E., Alan Carlisle, Eric James White, and C. C. Evans.
Plant Nutrient Content of Rainwater. J. Ecol. 56:497-504, 1968.
3. Andersson, Tage. Small-Scale Variations of the Contamination of
Rain Caused by Washout from the Low Layers of the Atmosphere.
Tellus. 21:685-692, 1969.
4. Bhandari, Narendra and Devendra Lai. Vertical Structure of the
Troposphere as Revealed by Radioactive Tracer Studies. J. Geophys.
Res. 75:2974-2980, 1970.
5. Boutron, C., M. Echevin, and C. Lorius. Chemistry of Polar Snow,
Estimation of Rates of Deposition in Antarctica. Geochim. Cosmo-
chim. Acta. 36:1029-1041, 1972.
6. Chojnacki, Adam. Chemical Composition of Atmospheric Precipitations
in Poland. II. Pamiet. Pulawski. 29:163-170, 1967. (Pol)
7. Chojnacki, Adam. Chemical Composition of Atmospheric Precipitations
in Poland. III. Pamiet. Pulawski. 29:171-184, 1967. (Pol)
8. Chojnacki, A. and M. Kac-Kacas. Content of Some Nutrition Components
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25. Button, J. T. Redistribution of the More Soluble Chemical Elements
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GENERAL
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2. Engelmann, R. J. Scavenging Prediction Using Ratios of Concentrations
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136
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