Transcript AERSCREEN Status and Update

AERSCREEN
Status and Update
James Thurman, Ph.D.
U.S. EPA/OAQPS/AQAD
Air Quality Modeling Group
2009 NESCAUM PMC Annual Meeting
Mystic, CT
AERSCREEN Finalization Workgroup
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Jim Haywood, Chair, Michigan DEQ
Karen Wesson, EPA
Roger Brode, EPA
James Thurman, EPA
Bob Paine, ENSR
Lloyd Schulman, TRC
Acknowledge Herman Wong, EPA Region
10
AERSCREEN: Description
• AERSCREEN is a tool that runs AERMOD in a
“screening” mode for a single source
– SCREEN option added to AERMOD in 1995 forces model to
calculate centerline concentration for each
source/receptor/meteorology combination
– SCREEN option limits output to 1-hour averages and selects
NOCHKD option to eliminate date sequence checking
– AERSCREEN program provides DOS interface to run AERMOD
in SCREEN mode including calls to MAKEMET, BPIPPRM and
AERMAP to generate necessary AERMOD inputs
• Spring 2008, incorporates output from AERSURFACE but does not
currently call/run AERSURFACE
• Spring 2009, updated to incorporate new features in AERMAP
– NED elevation data
– Location of grid files for NAD conversion
AERSCREEN Regulatory Status
“With respect to a screening version of AERMOD, a tool
called AERSCREEN is being developed with a beta version
expected to be publicly available in Fall 2005. SCREEN3 is
the current screening model in the Guideline, and since
SCREEN3 has been successfully applied for a number of
years, we believe that SCREEN3 produces an acceptable
degree of conservatism for regulatory applications and may
be used until AERSCREEN or a similar technique becomes
available and tested for general application. “
Appendix W Preamble Part IV, Section C, paragraph 7 pg.
68221
AERSCREEN Features
• Program developed by Jim Haywood, MI DEQ
– Data entered via prompts or by input file
• English or metric units via prompts, metric for input file
– Source types: point, volume, rectangular area,
circular area, and flare
• June 2009: added capped and horizontal stacks
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–
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Flat or complex terrain
PRIME building downwash
No deposition or polygon sources (AREAPOLY)
MAKEMET meteorology
AERSCREEN Features
• User can specify
– Probe distance (maximum distance of downwind
receptors)
– Flagpole receptors
– Elevation of location for PROFBASE (even for flat
terrain)
• Elevation above sea level for potential temperature profile
– Rural or urban (if urban, urban population)
– Ambient air distance (fence line distance)
• Search routine to find worst case impact
AERSCREEN Features
• Re-Use of Previous AERSCREEN Run Files
(AERSCREEN.INP)
• Performs errors checks on AERMOD and
AERMAP output and writes log file of
AERSCREEN run
• Includes factors for 3-hour, 8-hour, 24-hour and
annual averages – based on upper bound of
SCREEN3 factors
– 3-hour:
1.0
– 8-hour:
0.9
– 24-hour:
0.6
– Annual:
0.1
AERSCREEN Tests
• Significant testing to date shows good
results across wide range of applications
• “Good” defined as reasonable
conservatism compared to AERMOD
refined estimates
AERSCREEN Source Inputs
• Vertical (no cap) stack (POINT), capped
(POINTCAP), or horizontal (POINTHOR) stacks
– Emission rate (g/s or lb/hr)
– Stack parameters: height, inner diameter, exit temperature,
exit velocity or flow rate
• Flare (POINT)
– Emission rate (g/s or lb/hr)
– Stack height, total heat release rate, radiative heat loss
fraction (option to input value or use default SCREEN3
value, 0.55)
– Diameter and effective stack height calculated from inputs
AERSCREEN Source Inputs
• Volume (VOLUME)
– Emission rate (g/s or lb/hr)
– Release height (center of volume), initial lateral and vertical
dimensions of volume
• Area sources (AREA or AREACIRC)
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–
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–
Emission rate (g/s or lb/hr)
Release height above ground
Initial vertical dimension of plume
Long (xinit) and short (yinit) sides’ lengths of rectangular
area (AREA)
– Radius of circular area (AREACIRC)
– Rectangular source is assumed to have orientation angle
of 0
– Area source optimization option used in AERMOD
Building Downwash Inputs
• Maximum and minimum horizontal building
dimensions
• Building height
• Orientation of maximum building dimension to
North
• Orientation of stack relative to building center
(degrees from North)
• Distance between building center and stack
• AERSCREEN will calculate necessary inputs
and run BPIPPRM
Building orientation = 0 deg. to North
N
Angle of stack
to building
center
Stack to building
center distance
Height
Max length
Min length
Building orientation of 90 deg. to north
Stack 30 deg. from north
stack
Building orientation of 20 deg. to north
Stack 30 deg. from north
stack
N
N
20
30
min dim
30
max dim
y
y
x
x
Terrain inputs
• Coordinates of source
– Prompts: geographic or UTM
• If geographic, AERSCREEN converts to UTM for input to
AERMAP
– Input file: UTM, NAD83
• UTM zone
– If user enters geographic coordinates, calculated by
AERSCREEN
• NAD 27 or 83
– AERSCREEN converts coordinates to UTM NAD 83
• Probe distance (km)
– Default of 5 km for FLAT terrain, 10 km for non-FLAT
terrain
Terrain inputs
• Source elevation or allow AERSCREEN to use
AERMAP to calculate (non FLAT only)
• DEM or NED elevation filename listed in a usercreated file called demlist.txt
• Demlist.txt can also contain the location of the
grid files needed for NAD conversion.
– Must be named demlist.txt
Sample DEMLIST.TXT
Tells AERSCREEN what form of data for DATATYPE
keyword in AERMAP
NED : Must be either DEM or NED
---------------------------------------------------NADGRIDS grids\
NED_35703440.tif
Elevation file(s). If more than
one file used, one file per line
listed.
Location of NAD grid conversion files,
i.e., conus.las conus.los for NADGRIDS
keyword in AERMAP
* If keyword missing, files are assumed
to be in working folder
* If NADGRIDS path or elevation file path contains spaces, must enclose in quotes
MAKEMET
• MAKEMET loops through several meteorological
parameters:
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Wind speed (stable and convective)
Cloud cover (stable and convective)
Max/min ambient temp (stable and convective)
Solar elevation angle (stable and convective)
Convective velocity scale (w*) (convective only)
Mechanical mixing heights (stable only)
• Uses AERMET subroutines to calculate u* and
L, and also calculates convective mixing heights
• Generates surface and profile files for running
AERMOD in stand-alone mode
MAKEMET inputs
• Minimum and maximum temperature
– Average calculated by AERSCREEN
• Minimum wind speed
– Default of 0.5 m/s
– Minimum is 0.5 m/s
• Anemometer height
– Default 10 m
• Surface characteristics
Surface Characteristics and MAKEMET
• Three methods of inputting surface
characteristics into AERSCREEN
– User defined: non-sector based
– Seasonal tables from AERMET
• User specifies dominant land use type and moisture
conditions (average, dry, or wet)
• Non-sector based
– AERSURFACE output
• User enters AERSURFACE output filename or AERMET
stage 3 input filename
• Annual, seasonal, or monthly
• 1 to 12 sectors
• AERSURFACE is run for the source location by user
Surface Characteristics and MAKEMET
• MAKEMET is run for each temporal, sector
combination and met files generated for each
combination
– User defined SC: 1 set of files
– Seasonal tables: 4 sets of files
– AERSURFACE: 1 (annual/1 sector) to 144
(monthly/12 sectors) sets of files
AERSCREEN Steps
User actions
Input and validate data
Generate meteorological files
Model actions
Is there a source-receptor
direction dependency?
NO (flat terrain and no
downwash and not a
rectangular area source)
YES (terrain and/or
downwash or rectangular
area source)
PROBE
Run BPIPPRM if downwash
REFINE
FLOWSECTOR
Output
REFINE
Output
Example input file
Validation
page
Source
parameter
options
PROBE
• Executed for non-rectangular area sources, flat
terrain, and no building downwash (no direction
dependency)
• Receptors placed out to user-specified probe
distance
– 200 receptors or 25 m spacing (if spacing < 25 m)
• AERMOD is executed for each combination of
temporal and sector resolution of surface
characteristics
– i.e. 4 seasons and 2 surface sectors=8 AERMOD
runs
Source receptor orientation for PROBE
Source
FLOWSECTOR: Rectangular Area Sources
• Receptors placed from fence line out to userspecified probe distance on 5 degree diagonals
– Every 25 m or 200 receptors
• AERMOD executed for each temporal step and
surface roughness sector for each diagonal
– Westerly wind direction rotated by angle of diagonals
in AERMOD (WDROTATE)
– 4 seasons x 2 sectors x 7 diagonals = 56 runs
• Area source optimization (FASTAREA)
option used
Rectangular area source receptor orientation for FLOWSECTOR
30 deg.
diagonal
25 deg.
20 deg.
500 m
15 deg.
10 deg.
250 m
5 deg.
0 deg.
*diagonal is not used in receptor network
Sector 1
N
N
Sector 2
Sector 3
FLOWSECTOR: Other sources
• Receptors placed along 10 degree radials from
fence line out to probe distance
– Every 25 m or 200 receptors out to probe distance
• If terrain used, FLOWSECTOR creates
AERMAP input file and runs AERMAP
– Terrain heights for direction being processed used
• If downwash, projected dimensions for direction
being processed used
• The appropriate upwind sector for the processed
flow vector is used for surface characteristics
– 4 seasons x 36 radials = 144 runs
1
3
2
REFINE
• Find maximum concentration from PROBE or
FLOWSECTOR
• Use meteorology associated with the maximum
concentration and refine receptor spacing
– 1, 2, or 5 m spacing; dependent on downwind
distance of maximum concentration
• If terrain used, AERMAP rerun to reflect new
receptor locations in direction of maximum
concentration
• If downwash used, use projected building
dimensions associated with direction of
maximum concentration
AERSCREEN OUTPUTS
• Output files
– AERSCREEN.LOG
• Lists inputs, any warnings or errors during processing
– AERSCREEN.OUT
• List inputs, intermediate outputs and final output
– AUTOMATIC_DISTANCES.TXT
• Lists overall maximum 1-hour concentration by distance and
associated meteorology
– AERSCREEN.INP
• Output to screen
– Overall maximum 1-hour concentration and distance from source
• Includes 3, 8, 24-hour, and annual scaled concentrations
– 1-hour concentration at fence line for same meteorology as
overall maximum concentration
– These are written to AERSCREEN.OUT as well
Next steps
• Prepare code for beta release
– Additional code testing and compatibility with
updated AERMOD
– MAKEMET executable included in release
package
– AERMOD, AERMAP, and BPIPPRM available
on SCRAM
• User’s guide
Contact
James Thurman
[email protected]
(919) 541-2703
DEMONSTRATION