AERMOD Meteorological Data Available

March 17, 2006

Meteorological data for AERMOD are now available for use in regulatory applications in the state of Iowa. These data may be downloaded at no charge from the Technical Resources page on the Air Quality Bureau’s website here:

www.iowadnr.com/air/prof/tech/AERMODMetData.html

These data consist of 10 five-year sets for the period 2000 – 2004. The meteorological stations include Burlington, Cedar Rapids, Des Moines, Dubuque, Mason City, Moline, Omaha, Sioux City, Sioux Falls and Waterloo. It should be noted that some of the counties represented by each station have changed. Specifically, the meteorological stations representing Adams, Allamakee, Audubon, Cass, Clayton, Delaware, Dubuque, Hardin, Henry, Jackson, Jefferson, Muscatine, Poweshiek, Taylor and Van Buren Counties have changed. These changes are described in detail in the analysis used to determine the representivity of each station. The representivity analysis is available on the website, as well as a map indicating which meteorological data sets are considered representative for each county.

Previously, the DNR had planned to use land use data to create site-specific meteorological data sets for each modeling analysis. EPA commented that land use characteristics in the vicinity of the meteorological station should be used in processing the meteorological data sets. Based on this guidance, the land use characteristics at each meteorological data measurement site were used to generate model-ready meteorological data. Therefore, the meteorological data available on the website requires no additional processing.

Due to problems in the current version of AERMET, much of the data required additional manipulation to ensure that it was read and processed correctly at each stage by AERMET. Significant efforts were taken by the DNR to ensure that the input data and resulting processed data were accurate and complete. Comments are pending from EPA regarding the methodology used to complete the processing of these data. Therefore, these model-ready data may be subject to change in the future. DNR will notify meteorological data users of changes to each station’s data set if subsequent review and comments by EPA indicate a need to reprocess some or all of the data sets.

Questions or comments related to the met data should be directed to Brad Ashton of the Air Quality Bureau's modeling group. He may be reached by phone at (515)-242-6532, or by email at Brad.Ashton@dnr.iowa.gov.