Use of ASOS Meteorological Data in AERMOD Dispersion Modeling

The purpose of this memorandum is to provide some background information related to the transition to ASOS and to address more recent developments and potential issues associated with the use of NWS meteorological data for dispersion modeling. The memo also addresses EPA’s development of the AERMINUTE meteorological processor to take advantage of additional meteorological data resources that have become available in recent years to support AERMOD dispersion modeling. We also acknowledge that with the promulgation of new National Ambient Air Quality Standards (NAAQS) for NO₂ and SO₂ in 2010, concerns from the stakeholder community (regulatory agencies and industry) have arisen about the use of NWS data, specifically the use of low wind speeds (< 1 m/s) in AERMOD associated with application of the AERMINUTE tool.

Use of ASOS meteorological data in AERMOD dispersion modeling (pdf) (1.29 MB, March 8, 2013)