HiCLAS1  HiPERiSM Consulting, LLC, Linking with AS1MET Services

Model Equivalence Demonstration

Appendix W to Part 51 Guideline on Air Quality Models (see Appendix W) for Federal regulations specifies in paragraph 3.2.2(c) that use of an alternative model is acceptable if a Model Equivalence Demonstration (MED) is performed. This paragraph states that a MED is "established by demonstrating that the maximum or highest, second highest concentrations are within 2 percent of the estimates obtained from the preferred model. The option to show equivalency is intended as a simple demonstration of acceptability for an alternative model that is so nearly identical (or contains options that can make it identical) to a preferred model that it can be treated for all practical purposes as the preferred model."

AERMOD-HPCS has, to-date, exceeded this requirement  by a factor of 21 with a current MED score of

The following present details for the cases used at HiCLAS1 in a Model Equivalence Demonstration (MED) with AERMOD-HPCS (as alternative model) when compared to the U.S. EPA distribution (preferred model AERMOD.EXE). The list is sorted by AERMOD release date. New results are added as they come become available. Click on each link below to view details.

AERMOD 07026 (AERMOD-HPCS v1.8 versus AERMOD.EXE):

Send mail to george@hiclas1.com with questions or comments about this web site.
Copyright © 2007 HiCLAS1
Last modified:  04/15/2009