United States
Environmental Protection
Agency
Atmospheric Sciences
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S3-86/068 Mar. 1987
oEPA Project Summary
EPA Complex Terrain Model
Development: Description of a
Computer Data Base from the
Full Scale Plume Study, Tracy
Power Plant Nevada
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 pollutant
emissions in irregular mountainous ter-
rain, the Complex Terrain Model Devel-
opment Program was initiated in 1980
with Environmental Research and
Technology as the prime contractor.
Four field tracer studies were designed
and directed by the model developers
to test model estimates of plume im-
paction with observed tracer concen-
trations. The first study was conducted
in October-November 1980 at Cinder
Cone Butte, a roughly axisymmetrical,
isolated 100-m hill near Boise, Idaho,
and the second was performed along a
1.5-km section of Hogback Ridge, a
90-m high ridge near Farmington, New
Mexico. Studies three and four occurred
at the Tracy Power Plant near Reno,
Nevada and were designed as realistic,
full scale plume studies in a region of
irregular and complicated terrain with
tracer gas released through the smoke-
stack of an active power plant. Tracer
study number three in November 1983
was conceived as a modest feasibility
study for a more comprehensive fourth
study, but enough useful meteorological
and tracer data were assembled to sup-
port additional model development and
evaluation. The fourth study, designated
the Full Scale Plume Study, was con-
ducted in August 1984. and the data
collected, along with data from the third
study, comprise the data base described
in this report.
The Full Scale Plume Study comprised
14 experiments from August 6 to 27,
1984 for a total of 128 hours of data
collection, mainly during late evening
or early morning hours. The power plant
was maintained in a warm stand-by
condition as SF6 tracer gas and oil-fog
were injected into the base of a 91.4-m
smokestack. Also, CFSBr tracer gas was
released from one of three levels on a
150-m tower located about 1.2 km
east of the power plant and upwind of
the main targeted terrain. Meteoro-
logical data recorded on the 150-m
tower included wind, from triaxial
propeller anemometers at six levels, cup
and vane anemometers at three levels,
sonic anemometers at three levels, and
temperature from sensors at six levels.
Four 10-m towers and two electronic
weather stations occupied sites on sur-
rounding terrain to record wind and
temperature, and two vertical doppler
acoustic sounding systems operated
near the smokestack. Tethersonde
soundings were flown near the 150-m
tower to compliment data from the
tower and the nearby doppler sounding
system. Two radar-tracking balloon
systems recorded wind profiles up to 4
km during periods of tracer release. A
LIDAR system was use to sample quasi-
perpendicular transects through the oil-
fog plume emitted with SF6 tracer gas
from the top of the smokestack, and a
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program of plume photography estab-
lished plume-to-terrain interactions.
Prolonged periods of anticipated stable
conditions with westerly flow occurred
with frequent plume impaction on
sampler instrumented terrain east of
the stack. A tracer concentration data
base of over 11,000 hourly samples
was accumulated for both tracer gases
at 110 sites in surrounding terrain.
Tables of tracer gas release data in-
cluding emission rates, smokestack
plume heights, and tower release
heights were compiled to assist model-
ing efforts.
Data acquired during the preliminary
full scale plume study, tracer study
number three, from November 7 to 27,
1983 are also included with the Full
Scale Plume Study's data base. Ten
experiments were performed for a total
of 90 sampling hours employing a net-
work of 53 samplers, however only one
tracer gas. SF6, was used for smoke-
stack injection. Meteorological data
from the same 150-m tower, 10-m
towers, electronic weather stations,
doppler acoustic sounders and tether-
sondes were also recorded. Meteoro-
logical data recording on the 150-m
tower was continued from the end of
study number three, November 1983,
until the start of the Full Scale Plume
Study, August 1984, and these data
are included in the data base. All
meteorological and tracer gas concen-
tration data have been edited and placed
on magnetic tape and are now available
either as tape copies or by interactive
computer access.
This Project Summary was developed
by EPA'a Atmospheric Sciences Re-
search Laboratory, Research Triangle
Park, NC, to announce key findings of
the research project that Is fully docu-
mented In a separate report of the same
title (see Project Report ordering In-
formation 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 trans-
port and diffusion. For complex terrain,
mathematical modeling is confounded
because physical processes are more
complicated and meteorological measure-
ments are less representative than for
level terrain settings. Responding to this
fundamental problem, the U.S. EPA has
initiated the Complex Terrain Model
Development Program (CTMD), a major
effort to develop and demonstrate reli-
able models of atmospheric diffusion for
emissions in mountainous terrain.
An early step in the development of
this program was the convening of a
workshop concerned with these particular
problems. Following recommendations of
the workshop report, EPA's CTMD Pro-
gram involved a coordinated effort in
mathematical model development field
experimentation, and scaled physical
modeling. The program's basic objective
was to produce practical models with
demonstrated reliability. Initially, the
CTMD Program 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 on the
slopes of hills or ridges and because
models now in use have been challenged
extensively on this subject. The approach
has been to study stable plume inter-
actions in relatively simple terrain set-
tings, and then study them in more
complex situations.
EPA's prime contractor for the CTMD
Program is Environmental Research and
Technology, Inc. (ERT). Significant con-
tributions were also provided by EPA's
Fluid Modeling Facility (FMF), the National
Oceanic and Atmospheric Administra-
tion's (NOAA) Wave Propagation Labora-
tory (WPL) through their sophisticated
measurement capabilities, and NOAA's
Air Resources Field Laboratory Research
Division (ARLFRD) which conducted the
flow visualization and tracer experiments
and operated the real-time data acquisi-
tion and analysis system. The first field
experiment, a comprehensive tracer study
designated as Small Hill Impaction Study
No. 1 (SHIS #1) was carried out on Cinder
Cone Butte, a roughly axisymmetric.
isolated 100-m hill near Boise, Idaho,
during October-November 1980. Data
observed at SHIS #1, as tracer gas, SF6
and Freon 13B1 (CFSBr), emission rates,
locations and heights of release, tracer
concentrations, and meteorological data
from a 150-m tower and five 10-m towers,
tethersondes and free balloons were
subsequently delivered to EPA to form an
accessible computer data base. The
second field experiment, SHIS #2, was
performed along a 1.5 km section of the
Hogback Ridge near Farmington, New
Mexico to extend the modeling data base
to include a study of flow around a two-
dimensional ridge. As in SHIS #1, tracejtf
gas release data, tracer concentratio^
data from a network of samplers on the
ridge, and meteorological data from a
150-m tower, three 10-m towers, two
tethersonde systems and a three-path
crosswind optical anemometer system
were delivered to EPA as another acces-
sible computer data base.
This is a summary of a report that
describes CTMD field experiments three
and four conducted at the Tracy Power
Plant, Nevada designed to simulate pol-
lutant emissions from the smokestack of
an operating power plant in mountainous
terrain. Experiment three in November
1983 was conceived as modest feasibility
study for a more comprehensive fourth
experiment, or Full Scale Plume Study,
but enough meteorological and tracer
data were recorded to support additional
model development. The Full Scale Plume
Study occurred in August 1984, and the
data collected, along with data from the
third, or preliminary Full Scale Plume
Study, comprise the computer data base
described in the report.
The report describes the setting of the
Tracy Power Plant, the experimental ap-
proach, and the following types of data
archived on magnetic tape for both the
preliminary and Full Scale Plume Stud«
(FSPS): ~
Tower meteorological data, re-
corded as 5-min and 1-h averages
of wind, temperature, and turbulence
scales (sigma-u, -v, -w) at four to six
levels on a 150-m tower, and four
10-m towers located in the sur-
rounding terrain.
Tracer gas concentrations re-
corded as 1 h averages of SF6 and
Freon 13B1 (CFSBr) from a network
of samplers on targeted terrain.
Tethersonde meteorological data,
two profiles per hour, instantaneous
data of wind, temperature, relative
humidity, mixing ratio, pressure and
height.
Doppler acoustic sounder data,
10-min averages, wind and heights.
Sonic anemometer data, 5-min,
1-h averages, wind, temperature,
turbulence scales (sigma-u, -v, -w)
at three levels on the 150-m tower.
Radar balloon wind data, two
profiles per hour to 3 km, instan-
taneous data, wind, heights.
Electronic weather station data,
1 -h averages, wind and temperature.
Optical crosswind anemometer data,
5 or 10-min averages, windJ
components, speed and direction. "
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Minisonde data, one profile per
hour up to 3 km, instantaneous data,
winds, heights, temperature.
Table of tracer gas release data, emis-
sion rates, and location and heights of
release are included for the CFSBr tracer
gas in the Full Scale Plume Study, how-
ever, since the SF6 tracer was released
through the smokestack of an active
power plant, the height of release must
be considered to be the effective height
reached by the lofted plume. In the FSPS,
this height was obtained with LIDAR
transects of the plume, and included with
the other release data. In the preliminary
FSPS, November 1983, the LIDAR system
was not available, so the height of the
SF6 tracer release must be estimated.
Results
Preliminary FSPS
November 7 to 19,1983
All data are contained on the first 14
files of the FSPS data base magnetic
tape. These files hold all meteorological
measurements, SF6 tracer concentra-
tions, and geographical coordinates (x,y,z)
of sampler sites.
Meteorological Tower Data
File 1 has meteorological data from the
^50-m tower located upwind from the
rgeted terrain. Triaxial propeller anemo-
meters recorded wind components at four
levels, 5 m, 10 m, 100 m and 150 m
along with temperature and temperature
difference. Wind data are presented as
5-min averages of vector resultant speed
and direction, the vertical component w,
sigma-w, and sigma-theta. File 9 has data
recorded on two 10-m towers as 5-m
values of temperature and wind speed
and direction from cup-and-vane
anemometers
Tracer Gas Concentration Data
File 2 holds coordinates of 53 sampler
locations on the targeted terrain sur-
rounding the Tracy Power Plant. Files 3
and 4 have values of SF6 tracer con-
centrations detected during the two
weeks of operation. Concentrations are
values of CHI, parts per trillion (ppt), 1-h
averages.
Minisonde Data
Files 5 through 8 contain minisonde
data observed by two operating systems
located near the power plant. Data are
instantaneous values of wind, tempera-
ture, and height up to 3 km.
Optical Anemometer Data
:File 10 has 5-min path-averaged optical
emometer measures of wind compo-
nents and wind speed and direction along
two paths near targeted terrain features.
Data are 10-min averages of wind compo-
nents, speed and direction.
Electronic Weather Station Data
File 11 contains 1 -h averaged meteoro-
logical from two electronic weather
stations established near targeted terrain.
Data includes temperature, wind speed
and direction.
Doppler Acoustic Sounder Data
A doppler acoustic sounding system
was installed near the Tracy smokestack
to test the feasibility of obtaining real-
time information on vertical wind struc-
ture. Measurements of wind direction
and speed were made at 25-m height
intervals from 50 m to 400 m. File 12
holds 10-m values of doppler wind data.
Tethersonde Data
File 13 holds data recorded by the WPL
system located east of the Tracy smoke-
stack and upwind of the targeted terrain,
and file 14 has data from the ARLFRD
system near the smokestack. Meteoro-
logical data include values of height,
wind, temperature, relative humidity and
mixing ratio.
150-M Tower Data
October 14,1983 to July 10,1984
ERT erected and instrumented the
150-m tower at four levels and supplied
a data acquisition system for the tower in
October 1983, a month before the pre-
liminary FSPS began. Data were recorded
continuously through the preliminary
FSPS until July 1984, a month before the
FSPS started, as 1-h averages of the
same meteorological instrumentation in
operation during the preliminary FSPS.
Data recorded during this extended period
are stored on ten files, files 15 to 24,
each with one month's data, October
1983 to July 1984.
FSPS August 6 to 27, 1984
150-m Meteorological Tower Data
Two sets of meteorological data are
stored on magnetic tape. Files 25 to 40
hold 5-min averaged data; Files 41 to 56
has the recorded data averaged at 1-h
intervals. Data are recorded at six levels,
10 m, 50 m, 75 m, 100 m, 125 m, 150 m,
with triaxial propeller anemometers, cup-
and-vane anemometers, temperature and
temperature difference sensors. Values
include wind components, vector wind
direction and speed, turbulence scales
(sigma-u, -v, -w) and temperature and
temperature difference. In addition.
values of solar and net radiation were
recorded at a 1 m level.
Tracer Gas Concentration Data
Tracer gas concentrations, SF6 and
CF3Br, detected by a network of 110
samplers on surrounding terrain at 1 -h
intervals, are contained in two sets of
tape files. Files 57 to 70 have concentra-
tions of SF6 tracer, one file for each of 14
experiments, and files 71 to 84 have
values of CF3Br tracer for each experi-
ment. Concentrations are presented as
normalized values, CHI/Q(ns/m3) rather
than CHI (ppt) as is the preliminary FSPS.
Coordinates of each sampler are included
with tracer concentration values.
10-m Tower Data
Files 85 to 87 have 5-min averages of
wind and temperature from three 10-m
towers located in surrounding terrain,
and files 88 to 90 hold 1 -h averages of
the same measures. Data from a fourth
10-m tower instrumented at 2 levels, 1 m
and 10m, for wind measures and tem-
perature are held in file 91 as 2-min
averages and in file 92 as 1 -h averages.
150-m Tower Sonic
Anemometer Data
Sonic anemometer data of wind compo-
nents, temperature and turbulence scales
(sigma-u, -v, -w) are recorded at three
levels, 10 m, 100 m, 150 m, on the 150-
m tower. Files 93 to 95 have 5-min
averages for each level; files 96 to 98
have the 1 -h averages.
Doppler Acoustic Sounder Data
WPL operated two acoustic doppler
systems that had proven reliability during
the preliminary FSPS. One system was
located near the Tracy smokestack and
the other near the targeted terrain, close
to the Eagle Pitcher Industries, Inc. plant.
Profiles of wind speed and direction were
taken at 25-m levels from 50 m to 400 m
as 10-min averaged data. File 99 has
data from the Tracy stack site, and file
100 has data from the Eagle Pitcher
location.
Radar Balloon Wind Data
ARLFRD operated two radar-tracked
balloon (RABAL) systems, north and west
of the Tracy stack. Radar wind data were
acquired every 10 seconds during each
ascent, scheduled at 30-min intervals
throughout the 14 experiments. Data
consist of values of height, time, wind
speed and direction at each level. Files
101 to 113 hold data from the western
site, R-2, for 13 experiments, and files
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114 to 125 have data from the northern
site, R-4, for experiments 3 to 14.
Tethersonde Data
Files 126 to 139 contain tethersonde
data from profiles flown at the WPL sys-
tem near the 150-m tower during all 14
experiments. Values are measures of
height, wind speed and direction, tem-
perature, relative humidity and mixing
ratio.
Electronic Weatherstation Data
File 140, the last file on the magnetic
tape, holds hourly data from two elec-
tronic weather stations located near tar-
geted terrain. Data are measures of
temperature, wind speed and direction.
Conclusion
All data files are stored at the National
Computer Center, Environmental Re-
search Center, Research Triangle Park,
North Carolina, on the Sperry UNIVAC
1100/83 system's magnetic tape, nine-
track, odd parity, ASCII characters, 6250
BPI, tape number 007654. UNIVAC users
or users with interactive access may
assign the tape with UNIVAC Executive
Control Language statement, @ASG, T
FSPS,U9S//////Q,007654. Copies of
the tape can be produced and translated
into formats acceptable to any computer
using nine-track tape drives.
The EPA author, Lawrence E. Truppi, is on assignment from the National
Oceanic and Atmospheric Administration, to the Atmospheric Sciences
Research Laboratory, Research Triangle Park, NC 27711.
Peter L. Finkelstein is the EPA Project Officer (see below).
The complete report, entitled "EPA Complex Terrain Model Development-
Description of a Computer Data Base from the Full Scale Plume Study, Tracy
Power Plant, Nevada,' (Older No. PB 87-133 476/AS; Cost: $18.95, 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
U.S.OFRClALMAli
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
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