AERMIC Update

Roger W. Brode

U.S. EPA/OAQPS

Air Quality Modeling Group

9th Conference on Air Quality Modeling

October 9, 2008

Research Triangle Park, NC
Outline

• History of AERMIC• Reconstituted AERMIC• Summary of AERMIC Activities• Future plans for AERMOD – Overvie
• AMS/EPA Regulatory Model Improve

Committee initially formed in 1991; chto develop replacement for ISCST bastate-of-the-science

– AERMOD promulgated Dec. 2006– Membership of “new” AERMIC committe

• Roger Brode, OAQPS, Co-chair• Jeff Weil, CIRES-NCAR, Co-chair• Akula Venkatram, UC-Riverside• Al Cimorelli, EPA Region 3• Bret Anderson, EPA Region 7• Vlad Isakov, EPA/ORD/AMD

History of AERMIC
• New AERMIC committee has held two meetings i

(March and July 2008), with third meeting tentativ

for mid-November

• AERMIC reviewed status of AERMOD modeling s

activities of AIWG at initial meeting

• Key priority for AERMIC has been the Urban form

AERMOD

• However, AERMIC recognized significant overlap 

many issues, including Urban, Surface CharacteriMet Data

• AERMIC also recognized opportunities to address 

implementation issues by utilizing newly available 

Summary of AERMIC Activit
• AERMIC discussed issues associated with building do

AERMOD

– Recommended incorporating building processing function with– Eliminates need for separate BPIPPRM processor– Facilitates assessment of additional options for processing bui

information for PRIME, including alternative criteria for determstructure; possibility of combining influences from multiple struoption for looping through all influencing structures 

• AERMIC has developed an alternative implementation 

meander

– Preserves centerline value from current implementation but eli

dispersion component

– Could significantly optimize model runtime for some applicatio

for short-term design values

– May require additional guidance on applicability for long-term a

– Considering implementation in AERMOD as a regulatory optio– This approach is still under assessment

Some AERMIC Recommendat
• AERMIC has discussed the use of gridded progn

meteorological with AERMOD and will provide scsupport for the development and evaluation of oprelated to this effort

– Recommends implementing and testing approach of pro

gridded met data as pseudo-observations through AERaddition to approach currently implemented in MM5-AE

– Recommendation to invite experts in gridded meteorolo

modeling community to next (or future) AERMIC meetin

– Consideration of options to incorporate some non-stead

characteristics in AERMOD modeling system, possibly gridded meteorological model inputs

Some AERMIC Recommendat
• Building on plans to enhance AERSURFAC

combining land cover and elevation data, Ais developing an approach to address a wiof issues by utilizing this data directly in the 

• Land cover and elevation data (SRTM-NED

fed directly to AERMOD to develop sourcemeteorology accounting for land cover and heights around source and met tower

• Meteorology adjustments will account for e

urban canopy on wind profiles

AERMIC - Future Plans for AER
• This approach could eliminate many imple

issues, especially related to urban applicat

– No distinction between “rural” and “urban” sour– No requirement to estimate “effective” populati

surrogate for urban influences

– Spatial and temporal variability of urban heat is

influence will be accounted for

– Representativeness of met data will always be 

but influence of surface characteristic variability mitigated

• Considerable work will be required to imple

this plan, including performance evaluation

Future Plans for AERMOD (co
• Incorporating fuller range of data directly i

AERMOD may eliminate need for preproc

including AERMAP, AERMET, and AERSU(as well as BPIPPRM)

• Access to “raw” input data in AERMOD ma

additional enhancements, such as directio

“hill height scales” for terrain influences, cnot practical to implement

• New AERMOD structure will better accom

future enhancements as new data sources 

• Downside is that this plan is not likely to sp

AERMOD!

Future Plans for AERMOD (co
Questions?