On April 24, 2018, the EPA finalized updated versions (v18081) of the air dispersion modeling software AERMOD, AERMAP and AERMET.
AERMET version 18081 includes bug fixes to subroutines enabled during Stage 3 of the meteorological pre-processor. Please refer to the AERMET user guide for details, which is available on the SCRAM website.
Due to the AERMET modifications, the DNR has reprocessed the meteorological data available on the DNR’s website (Version E).
The sensitivity of AERMOD to the changes being introduced by the reprocessed meteorological data was tested. On average, users can expect a negligible amount of change to predicted concentrations for both the change to the latest version of the meteorological data and the new version of AERMOD.
Applicants should begin using the latest version of AERMOD (v18081) and meteorological data (Version E) immediately. The previous version of the meteorological data (Version D) can be used in cases where it has been approved in a dispersion modeling protocol.
The revised surface and upper air meteorological data files are available under the Dispersion Modeling page on the Department’s website.
Please contact Alyssa Fizel at Alyssa.Fizel@dnr.iowa.gov or by phone at (515) 725-9566, with any questions or comments on this update.