United States
Environmental Protection
Agency
Atmospheric Sciences
Research Laboratory
Research Triangle Park NC 2771J
Research and Development
EPA/600/S8-88/067 May 1988
Project Summary
A Computer Data Base from
EPA's Complex Terrain Field
Studies: Description of a SAS Computer
Data Base from Tracer Field Studies at
Cinder Cone Butte, ID, Hogback Ridge,
NM, and the Tracy Power Plant, NV
Lawrence E. Truppi
As part of the U. S. Environmental
Protection Agency's effort to develop
and demonstrate a reliable model of
atmospheric dispersion for pollution
emissions in irregular mountainous
terrain under stable atmospheric
conditions, the Complex Terrain
Model Development Program was
initiated in 1980. Field tracer studies
at three locations In mountainous
terrain were designed and directed
by the model developers to test
model estimates of plume impaction
with observed tracer concentrations.
The first study was conducted in
October-November 1980 at Cinder
Cone Butte, a roughly axisym-
metrical, isolated 100-m hill near
Boise, Idaho, and the second study
was performed along a 1.5-km
section of Hogback Ridge, a 90-m
high ridge near Farmington, New
Mexico, in October 1982. In both
studies, tracer gases, SF6 and CF3Br,
were released upwind of the targeted
terrain from a source suspended
from a mobile crane or from a level
on a 150-m tower. A 150-m tower
was erected and instrumented to
record profiles of wind and
temperature, and several 10-m and
30-m towers were installed on the
slopes of the targeted terrain.
Meteorological instrumentation also
included tethersonde and pibal
observations. An array of
approximately 100 Tedlar bag
samplers on the targeted terrain
recorded 1-hourly values of tracer
concentrations.
The tracer field study at a third
location, the Tracy Power Plant near
Reno, Nevada, entitled the Full Scale
Plume Study, differed since SF6
tracer gas was injected into the base
of the smokestack of a warm, active
electric power plant, and CF3Br
tracer was emitted from a level on a
150-m tower. Meteorological instru-
mentation from a specially erected
150-m tower and smaller towers was
similar to the first two studies, with
the addition of sonic anemometers,
vertical doppler acoustic sounders,
and two radar-tracking balloon wind
systems. A lidar system was also
employed to determine effective
plume height of the SF6 tracer as
emitted from the smokestack.
To facilitate analysis of this great
amount of data, tape files from the
three tracer field studies were
converted into SAS (Statistical
Analysis System) data sets and
stored on the IBM computer system
at EPA, Research Triangle Park, North
Carolina. The various SAS data sets
are described in this report.
This Project Summary was
developed by EPA's Atmospheric
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Sciences Research Laboratory, Re-
search Triangle Park, NC, to an-
nounce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering Information at
back).
Introduction
The extensive development of energy
resources, especially in the mountainous
terrain of the western United States, has
generated concern about the resulting
impact on air quality (as well as on water
and land quality). Even in relatively
simple situations, it has been difficult to
produce reliable calculations of
atmospheric transport and diffusion. In
complex terrain, the mathematical
modeling problem is compounded
because the physical processes are
more complicated and meteorological
measurements are less representative
than in level terrain settings. Responding
to this fundamental problem, the U.S.
Environmental Protection Agency (EPA)
has embarked upon the Complex Terrain
Model Development program (CTMD), a
major effort to develop and demonstrate
reliable models of atmospheric
dispersion for emissions in mountainous
terrain.
An early step in the development of
this program was the convening of a
workshop on problems in modeling
atmospheric dispersion over complex
terrain. In concert with recommendations
in the workshop report, EPA's CTMD
Program developed a coordinated effort
in mathematical model development,
field experimentation, and scaled
physical modeling. The program's basic
objective focused on the problem of
stable plume impaction/interaction with
elevated terrain. This phenomenon was
singled out because of the likelihood of
relatively high concentrations and
because models now in use have been
challenged on this point. The approach
has been to study stable plume
interactions first in relatively simple
terrain settings and subsequently in more
complex situations
EPA's prime contractor for carrying
out the CTMD program was
Environmental Research and Tech-
nology, Inc., (ERT). Significant contri-
butions were also provided by EPA's
Fluid Modeling Facility (FMF), by the
National Oceanic Atmospheric Admin-
istration's (NOAA) Air Resources Field
Research Division (ARLFRD) and Wave
Propagation Laboratory (WPL). ARLFRD
conducted flow visualization, tracer
experiments, and operated the real-time
data acquisition and analysis systems.
WPL contributed with their sophisticated
measurement capabilities with optical
and acoustic anemometers and lidar
instruments.
Tracer field studies at three locations
were designed and directed by the
model developers to test model
estimates of plume impaction on
elevated terrain with observed tracer
concentrations. Usually, two tracer gases
and a visible oil-fog were emitted
simultaneously to impinge on a targeted
terrain feature instrumented with a
network of gas samplers. A mete-
orological monitoring system based on a
150-m tower recorded profiles of wind,
temperature and turbulence concurrently
with tracer releases.
The first study, Small Hill Impaction
Study No .1 (SHIS #1), was conducted in
October-November 1980 at Cinder
Cone Butte (CCB), a roughly axi-
symmetrical, isolated, 100-m hill near
Boise, Idaho. Eighteen quantitative tracer
experiments were conducted, each last-
ing 8 hrs at night or early morning. Two
tracer gases, SF6 and CF3Br (Freon),
were released from sources suspended
from a mobile crane upwind from a
network of gas samplers on the targeted
terrain. Tracer gas source data (emission
rates, locations and heights of tracer and
oil-fog releases), tracer concentrations
and meteorological data from the 150-m
tower, five 10-m towers on the hill
slopes, tethersonde and pibal systems
were subsequently delivered to EPA to
form an accessible computer data base.
The second tracer field study, SHIS
#2, in October 1982, was conducted
along an approximately 1.5-km section
of the 90-m Hogback Ridge (HER) near
Farmington, New Mexico, to extend the
modeling data base to include a study of
wind flow and dispersion around a two-
dimensional ridge. Eleven quantitative
8-hr tracer experiments were performed
at night or early morning. Two tracer
gases, SF6 and CF3Br (Freon), were
released from sources suspended from a
mobile crane or from a level on a 150-
m tower upwind from a network of
samplers on the targeted terrain, HBR.
Meteorological data from a 150-m
tower, three smaller towers of 60-m,
30-m and 10-m heights, two tether-
sondes, three crosswind optical ane-
mometers, and tracer concentrations of
SF6 and CF3Br were assembled into a
computer data base
The third location for CTMD tracer
field studies was the Tracy Power Plant
near Reno, Nevada, where a tracer ga(
SF6, was injected into the base of
warm, active electric power plant in
region of irregular and complex terrain. >
preliminary field experiment wa
performed in November 1983 as
modest feasibility study for the mor
comprehensive experiment to follow, bi
enough usable data were collected ti
support additional model developmen
and evaluation.
The final CTMD tracer field study, thi
Full Scale Plume Study, (FSPS), wa
conducted at the Tracy Power Plant witl
a total of 14 experiments from August I
to 27, 1984, mainly during the lati
evening or early morning hours. Stud'
hours encompassed a variety o
conditions ranging from very stable witl
light winds to morning inversion breakui
and fumigation. Meteorological dat;
recorded on the 150-m tower includei
wind and temperature data from si
levels and sonic anemometer data fron
three levels. Four 10-m towers and tw<
electronic weather stations were locate*
on terrain surrounding the power planl
Two vertical doppler acoustic soundini
systems were operated near thi
smokestack. Tethersonde ascents wen
flown near the 150-m tower ti
complement data from the tower and ,
nearby doppler acoustic sounder. Twi
radar-tracking balloon systems obtainei
wind profiles up to 4 km during period
of tracer release. A lidar system wa
used to sample quasi-perpendicula
transects through the oil-fog plumi
emitted with the SF6 tracer to determini
effective height of tracer release an(
plume spreading. Meteorological dat;
were assembled into a computer dat;
base that included tracer concentratioi
data of over 11,000 hourly samples wa:
assembled for both tracer gases.
The objective of this report is t<
describe the assemblage of data from a
CTMD tracer field studies into a new dati
base applicable to the Statistical Analysi:
System (SAS) of computer software. SAJ
System software is used to read tape:
with data from all three CTMD tracer fielc
studies and organize the values into ;
series of SAS data sets to form a nev
data base. SAS data sets an
automatically self-documenting sinc<
they contain both the data values an<
their descriptions. Now, the new dati
base of CTMD tracer field studies wouli
be available to SAS software program
found on most university mainframi
computer systems where SAS softwan
products such as graphics and statistice
analysis procedures could be utilized ti
full advantage. This report assume
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jeader familiarity with the SAS System. It
'describes the various SAS data sets
associated with each tracer study and
identifies data variables included in each
SAS data set.
Results
Tracer Field Study at Cinder Cone Butte,
Idaho
All data are contained in five SAS data
sets:
1. LETCTM1.CCBTMPWN
Meteorological data recorded
as 5-min averages of
temperature, wind compo-
nents turbulence scales
(sigma-u, -v, -w) at 8 levels
on a 150-m tower, and at 2
levels on five 10-m towers
located on the targeted terrain.
2. LETCTM1.CCBTETH
Tethersonde meteorological
data of instantaneous measures
of wind, temperature, relative
humidity, mixing ratio, pressure
and height, one sounding per
hour.
3. LETCTM1.CCBPBL
Pilot balloon data of wind
direction and speed, one
sounding per hour.
4. LETCTM1 .CCBCONC
Tracer concentrations of SF6
and CF3Br gas recorded as
sequential 1-hr or 10-min
samples, (ppt).
5. LETCTM1.CCBMDA
Modelers' Data Archive data
set contains meteorological
variables estimated at release
height for SF6 or CF3Br tracer,
tracer source data, and ob-
served 1-hr averaged tracer
concentration data.
Tracer Field Study at Hogback Ridge,
New Mexico
All data are contained in five SAS data
sets:
1. LETCTM1 HBRWNTMP
Meteorological data recorded
as 5-min averages of
temperature, wind compo-
nents, turbulence scales
(sigma-u, -v, -w) at 10
levels on a 150-m tower.
2. LETCTM1.HBRTWRS
Meteorological data recorded
as 5-min averages of
temperature, wind compo-
nents, turbulence scales
(sigma-u, -v, -w) at 5 levels
on a 30-m tower, 3 levels on a
10-m tower, and 2 levels on a
60-m tower.
3. LETCTM1.HBRTETH
- Tethersonde meteorological
data as instantaneous
measures of wind, temper-
ature, relative humidity, mixing
ratio, pressure and height, one
sounding per hour at site 1.
Tethersonde data of wind and
temperature from point of
tracer release, site 2.
4. LETCTM1.HBROPTA
Optical anemometer data as
10-min path-averaged
crosswind speeds from three
paths aligned along the base,
slope and crest of Hogback
Ridge.
5. LETCTM1.CONCS
Tracer concentrations of SF6
and CFSBr gas recorded as
sequential 1-hr or 10-min
samples, normalized values
(ns/m3).
Tracer Field Study at the Tracy Power
Plant, Nevada
All data are contained in nine SAS data
sets:
1. LETCTM1.FSPSTW
Meteorological data recorded
as 5-min averages of tem-
perature, wind components,
turbulence scales (sigma-u, -
v, -w) at 6 levels on a 150-m
tower.
2. LETCTM1.FSPSONIC
- Sonic anemometer data as 5-
min averages of temperature,
wind components and tur-
bulence scales (sigma-u, -v,
-w) at 3 levels on a 150-m
tower.
3. LETCTM1.FSPSDAS
Doppler acoustic sounder data
as 10-min averages of wind
direction and speed at 25-m
height intervals from 50 m to
400 m.
4. LETCTM1.FSPSRBL
Radar balloon data as
instantaneous wind data two
profiles per hour to 3 km.
5. LETCTM1.FSPSTETH
Tethersonde meteorological
data as instantaneous
measures of wind, temperature,
relative humidity, mixing ratio,
pressure and height, 2 profiles
per hour.
6. LETCTM1.FSPSTW10
Meteorological data recorded
as 5-min averages of tem-
perature, wind components,
turbulence scales (sigma-u, -
v, -w) at 1 level on four 10-m
towers on surrounding terrain.
7. LETCTM1 FSPSELWX
Electronic weather station data
as 1-hr averages of temper-
ature, wind direction and speed
from two sites in surrounding
terrain.
8. LETCTM1.FSPSCONC
Tracer concentrations of SF6
and CF3Br gas recorded as
sequential 1-hr samples, (ppt).
9. LETCTM1.FSPSMDA
Modeler's Data Archive data set
contains meteorological vari-
ables estimated at the height of
SF6 tracer release, plume
height determined by lidar
measure, and at the height of
CFSBr from a 150-m tower.
Conclusion
This report describes the data
recorded during three tracer field studies
conducted as part of EPA's Complex
Terrain Model Development program.
Data are contained in a series of SAS
data sets, and, utilizing the self-
documentation feature of SAS software,
tables are presented to identify all
variables recorded. Additional tables in
the report present tracer release data and
other information needed for testing
various dispersion models or other
applications.
The SAS data sets are arranged on
magnetic tape so that acquisition is easily
accomplished by any user with
interactive computer access to the IBM
computer at the National Computer
Center at Research Triangle Park or with
access to a computer capable of reading
standard nine-track magnetic tape.
Tape copies are available upon request
to the author.
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Lawrence E. Truppi,, (also the EPA Project Officer, see below) is on assignment
to the Atmospheric Sciences Research Laboratory, Research Triangle Park,
NC 27711 from the National Oceanic and Atmospheric Administration.
The complete report, entitled "A Computer Data Base from EPA's Complex
Terrain Field Studies: Description of a SAS Computer Data Base from Tracer
Field Studies at Cinder Cone Butte, ID, Hogback Ridge, NM, and the Tracy
Power Plant, NV," (Order No. PB 88-191 424/AS; Cost: $19.95, subject to
change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Atmospheric Sciences Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC27711
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
iTs.POSTAG?"
HO .253
Official Business
Penalty for Private Use $300
EPA/600/S8-88/067
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