Meteorological Data

This Web page contains ready-to-run meteorological data suitable for AERMOD (version 12060).

Meteorological data processed with AERMET (versions 06341 and 04300) for ISC applications and earlier versions of AERMOD (versions 09292 and older) have been removed from this site.

General information for development of AERMOD-ready meteorological data

MPCA air dispersion modeling staff has, in recent years, provided pre-processed meteorological data for air modeling using ISC and AERMOD (versions 06341 and older). This update to the MPCA pre-processed meteorological data set reflects the most recent version (to date) of AERMET (version 11059), as well as the new EPA pre-processor AERMINUTE (version 11059) and the use of EPA’s surface characteristics tool, AERSURFACE (version 08009).

There are approximately 80 meteorological surface observing stations in the state of Minnesota, consisting of ASOS (Automated Surface Observing System) and AWOS’ (Automated Weather Observing System) sites. The overwhelming majority of these sites are located on airport property and follow guidelines laid out in the Federal Meteorological Handbook (see links below). The 87 stations from Minnesota, as well as Wisconsin, South Dakota, and North Dakota, were examined using preliminary processing to determine usability for modeling purposes. Stations passing the first test of usability (for missing and calm data) were then further examined and refined to include site-specific yearly-averaged moisture conditions, corrected locational data, and more recent data (2009 and 2010).

No on-site meteorological data is included with this update (for AERMOD versions 11103, 11353 or 12060). Read more about the data below.

For any questions regarding the development of the meteorological data sets, please contact Melissa Sheffer at 651-757-2718or at Melissa.Sheffer@state.mn.us.

AERMET (version 11059) data (MPCA pre-processed and AERMOD-ready)

Meteorological data sets are listed by the meteorological surface station’s three-letter call sign. Ex., MSP = Minneapolis/St. Paul Int’l Airport. Currently, each surface station is processed with one of three available upper air stations, based on proximity: MPX (Chanhassen, MN), INL (International Falls, MN), and ABR (Aberdeen, SD).

All met data currently is processed for the 5-year period of 2006 – 2010. Variations to the 5-year period will be noted in the table.

Except for those with an asterisks (*), stations with a WBAN # of 99999 prior to 2009 changed to their current WBAN # on November 24, 2008.

*FFM’s WBAN of 94966 changed to 24025 on October 26, 2010.
**STP’s WBAN of 99999 changed to 14927 on January 1, 2004.

Data files contained within each zip file follow the 8-character naming convention of SFCUPAYY (ex., MSPMPX06):

• The first three characters, SFC, represents the meteorological surface station ID (ex., MSP);
• The fourth through sixth characters, UPA, represents the upper air station ID (ex., MPX for the Chanhassen, MN upper air station);
• The last two characters, YY, represents the two digit year (ex., 06 = 2006, 10 = 2010, 5Y = five-year concatenated file, etc.).

Each zip file contains:

• Aerial views of the meteorological surface station (SFC_2008Aerial_DNRLandview.bmp)
• 5-year wind roses (SFCUPA5Y.bmp)
• Surrounding land use and land cover within 1.0 kilometers of surface station (SFC_01km_1992LULC.jpg)
• 5-year wind frequency counts (SFCUPA5Y_FreqCount.csv)
• AERSURFACE outputs (SFC_Ave_AERSURFACE.out, SFC_Dry_AERSURFACE.out, SFC_Wet_AERSURFACE.out)
• 5-year concatenated profile file (SFCUPA5Y.pfl)
• 5-year concatenated surface file (SFCUPA5Y.sfc)
• A Read-Me file containing yearly moisture conditions for the surface station and 5-year period of use (ReadMe_SFC.txt)
• 5 subfolders for each individually-processed year, each of which contains:
  • Yearly wind rose (SFCUPAYY.bmp)
  • AERMET stage 3 input file (SFCUPAYY.in3)
  • Wind frequency counts (SFCUPAYY_FreqCount.csv)
  • AERMET stage 3 message file (SFCUPAYY.ms3)
  • AERMET stage 3 output – profile file (SFCUPAYY.pfl)
  • AERMET stage 1 report file (SFCUPAYY.rp1)
  • AERMET stage 2 report file (SFCUPAYY.rp2)
  • AERMET stage 3 report file (SFCUPAYY.rp3)
  • AERMET stage 3 output – surface file (SFCUPAYY.sfc)

Guidance for selecting the appropriate meteorological data set

40 CFR Part 51, Appendix W, 8.3.a. states that the following should be considered when choosing representative meteorological data:

1. The proximity of the meteorological monitoring site to the area under consideration;
2. The complexity of the terrain;
3. The exposure of the meteorological monitoring site;
4. The period of time during which data are collected.

Section 8.3.c further states that “of paramount importance is the requirement that all meteorological data used as input to AERMOD must be both laterally and vertically representative of the transport and dispersion within the analysis domain.” It also states, “…the surface characteristics input to AERMET should be based on the topographic conditions in the vicinity of the meteorological tower.”

MPCA air dispersion modeling staff has made an effort to make available recent meteorological data, so as to more accurately reflect recent meteorological conditions. In order to determine the most representative meteorological station for use, it is recommended that the subject source consider meteorological sites with similar features. Features to qualitatively consider include:

• Wind direction and wind speed patterns
• Terrain influences on wind patterns
• Surface characteristics (albedo, Bowen ratios, surface roughness), based on surrounding land use
• Proximity
• Time period for correlation with MPCA FAMOUS data packets
• AERMINUTE (to minimize calm hours) (if applicable, per EPA guidance)

In areas of the state where complex or highly variable terrain occurs (river valleys, lake shores, northeast Minnesota, etc.), it is recommended that a meteorological set be chosen based mainly on surface characteristics, wind patterns, land use, and terrain. In areas of Minnesota where terrain is relatively flat and invariable, then proximity, surface characteristics, land use, and wind patterns should be examined. No matter the subject source and the reliance on past meteorological sites, please provide explanation/reasoning for your choice of met sets in the modeling protocol form (AQDMP-01 form).

MPCA air modeling staff at this time is contemplating a quantitative approach for the selection of meteorological data sets. Please check back for any updates.

For any questions regarding the choice of a meteorological data set(s) for your source, please contact MPCA air dispersion modeling staff to discuss.

Documents

• Meteorological surface stations (aq2-51)
• Region 5 Meteorological data processing (aq2-50)

Visualizations and figures

• Coming soon – Google Earth .kmz file
• Meteorological surface stations overlaid on a 1992 Land Use Land Cover (LULC) map for Duluth, MN (aq2-52a)
• Meteorological surface stations overlaid on a National Elevation Data (NED) map for Duluth, MN (aq2-52b)
• Meteorological surface stations overlaid on a 1992 Land Use Land Cover (LULC) map for the area of the Twin Cities Metro (aq2-53a)
• Meteorological surface stations overlaid on a National Elevation Data (NED) map for the area of the Twin Cities Metro (aq2-53b)
• Meteorological surface stations overlaid on a blank map for Minnesota and surrounding states (for stations that will be available on the MPCA air dispersion modeling webpage) (aq2-54a)
• Meteorological surface stations overlaid on a 1992 Land Use Land Cover (LULC) map for Minnesota and surrounding states (aq2-54b)
• Meteorological surface stations overlaid on a blank map for the state of Minnesota and the surrounding states, for stations that will be and will not be available on the MPCA air dispersion modeling webpage and that were processed using AERMINUTE (aq2-54c)
• Meteorological surface stations overlaid on a blank map for the state of Minnesota and the surrounding states, for stations that will be and will not be available on the MPCA air dispersion modeling webpage (aq2-54d)
• Meteorological surface stations overlaid on a National Elevation Data (NED) map for the state of Minnesota and the surrounding states (aq2-54e)