AERMOD, the preferred model of the U.S. EPA for near-field air dispersion modeling, requires the use of two meteorological files: the surface (.SFC) and profile (.PFL) files.

1. Prepared by:
BREEZE Software
12770 Merit Drive | Suite 900 | Dallas, TX 75251
+1 (972) 661-8881 | breeze-software.com
George J. Schewe, CCM, QEP
June 26, 2012
Generating and Using
Meteorological Data in AERMOD

2. M t l i T t tiMeteorology in Transportation
Hot Spot ModelingHot Spot Modeling
 AERMOD mentioned
i S ti 3 6in Section 3.6
 Focus here on
AERMOD input filesAERMOD input files
 Section 7.5 -
Incorporating
Meteorological Data
 From where do the
data come?data come?

3. Wh t i AERMOD?What is AERMOD?
“A steady-state plume model that
incorporates air dispersion based on
planetary boundary layer turbulence
structure and scaling concepts,
including treatment of both surface and
elevated sources, and both simple and
complex terrain.”
Support Center for Regulatory Air Models -
www.epa.gov/scram001/dispersion_prefrec.htm

5. H t S t M d li PHot-Spot Modeling Process
1. Determine need for analysis
2. Determine approach, models, data
3. Estimate on-road motor vehicle emissions
4. Estimate emissions from road dust, construction, other
sourcessou ces
5. Select AQ model, meteorology, roadway configurations,
receptors, background concentrations
6 C l l t d i l t NAAQS d6. Calculate design values, compare to NAAQS, and
determine conformity
7. Consider mitigation or control measures and repeat

7. Meteorological Data for AERMOD
 Finding representative meteorological
d t NWS FAA SCRAM itdata – NWS, FAA, SCRAM, onsite
 Surface and upper air data
 AERSURFACE for albedo, Bowen
ratio, surface roughness
 AERMET preprocessor

8. S l ti M t l fSelecting Meteorology for
Project-Level Hot-Spot AnalysisProject Level Hot Spot Analysis
 Surface met data – NWS, Onsite, other
 Offsite met data – minimum five years
 Onsite met data – minimum one year
U i t d t Upper air met data
 Surface characteristics, land use
 Population data – used for urban-rural
 Representative of the project area?

9. R t ti fRepresentativeness of
Meteorology for Hot-Spot AnalysisMeteorology for Hot Spot Analysis
 Proximity of project to met data site
 Similarity of land use and surface
characteristics
 Time period of data
 Similarity of terrain features Similarity of terrain features
 Climate similarities

10. Ai t Sit LULCAirport vs Site LULC

11. S f D tSurface Data
 National Weather Service Data is typical
 TD-3505 format (Integrated Hourly Surface TD 3505 format (Integrated Hourly Surface
Data) obtained from National Climatic Data
Center in Asheville or
ftp://ftp3.ncdc.noaa.gov/pub/data/noaa
 Minute data obtained from NOAA at
ftp://ftp ncdc noaa gov/pub/data/asos-oneminftp://ftp.ncdc.noaa.gov/pub/data/asos-onemin
 Verify station location at
http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?WWDI~StnSrch

12. htt // i d / / d /http://gis.ncdc.noaa.gov/map/cdo/

13. htt // i d / / dhttp://gis.ncdc.noaa.gov/map/cd
o/o/

14. St ti L tiStation Location

15. Station LocationStation Location
BiGoogle Earth Bing

16. U Ai D tUpper Air Data
 National Weather Service Data is typical
 FSL Format (Forecast Systems Laboratory) FSL Format (Forecast Systems Laboratory)
obtained from NOAA online at
http://www.esrl.noaa.gov/raobs
 Verify station location at
http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?WWDI~StnSrch

17. Upper Air Observation sites

18. Upper Air Station LocationUpper Air Station Location
BiGoogle Earth Bing

19. L d ULand Use
 From the USGS Seamless Server at
http://seamless.usgs.gov/website/seamless/viewer.htm
 Currently only NLCD92 format

20. R i f L d UReview of Land Use
Facility Landuse

21. AERSURFACE O t tAERSURFACE Output
Season Sect Alb Bo Zo
SITE_CHAR 1 1 0.17 0.92 0.026
SITE_CHAR 1 2 0.17 0.92 0.013
SITE CHAR 1 3 0.17 0.92 0.012
 Alb – albedo is the
amount of solar radiation
reflected by the surface
SITE_CHAR 1 3 0.17 0.92 0.012
SITE_CHAR 1 4 0.17 0.92 0.030
SITE_CHAR 1 5 0.17 0.92 0.021
SITE_CHAR 1 6 0.17 0.92 0.128
SITE_CHAR 1 7 0.17 0.92 0.571
 Bo – Bowen ratio is the
ratio of sensible to latent
heat_
SITE_CHAR 1 8 0.17 0.92 0.319
SITE_CHAR 1 9 0.17 0.92 0.285
SITE_CHAR 1 10 0.17 0.92 0.035
SITE_CHAR 1 11 0.17 0.92 0.018
 Zo – surface roughness
length is related to the
land use which interrupts
SITE_CHAR 1 12 0.17 0.92 0.030
SITE_CHAR 2 1 0.16 0.66 0.036
SITE_CHAR 2 2 0.16 0.66 0.019
SITE_CHAR 2 3 0.16 0.66 0.017
land use which interrupts
smooth-flowing winds at
the surface
SITE_CHAR 2 4 0.16 0.66 0.044
SITE_CHAR 2 5 0.16 0.66 0.031
SITE_CHAR 2 6 0.16 0.66 0.163

22. AERMET P iAERMET Processing
 Stage 1 and 2 
Raw Sounding
File
AERMET QA
-------------- Stage 1 and 2 -----------------
Stage 3
Surface
Raw
S f Fil
AERMET QA
File
MERGE
Surface File
AERMET QA
Raw
MERGE
Upper
Manual/AERMET
On-site File
Explicit Land
Bowen ratio,
roughness,
QA
1-min data AERMINUTE
Explicit Land
Use Analysis
g ,
albedo

23. F t f AERMETFeatures of AERMET
Processes one minute and hourly surface observations,
twice-daily upper air soundings, and on-site
measurements:
AERMINUTE processes one minute u and AERMINUTE – processes one minute u and 
AERMET – processes in three stages
 Stage 1: Extracts/processes data from AERMINUTE,S age ac s/p ocesses da a o U ,
archived data files and performs quality assessment (QA)
 Stage 2: Merges all data from Stage 1 and stores these
data together in a single file
 Stage 3: Reads merged meteorological data and estimates
b d l t f b AERMODboundary layer parameters for use by AERMOD

24. Surface Turbulence Parameters
 AERMET computes turbulence parameters
for use in AERMOD
 Sensible heat flux
 Surface friction velocity
 Convective velocity scale Convective velocity scale
 Convective boundary layer height
 Vertical potential temperature gradientp p g
 Stable boundary layer height
 Monin-Obukhov length

25. Processed Met DataProcessed Met Data
Met Data File using PCRAMMETMet Data File using PCRAMMET
Surface Met Data File using AERMET

26. Questions/Discussion?
George J. Schewe, CCM, QEP
(859) 341-8100(859) 341-8100
gschewe@trinityconsultants.com
www trinityconsultants comwww.trinityconsultants.com