File: ABSTRACT.TXT


                     Weather Station Data Files


            Center for Exposure Assessment Modeling (CEAM)
 National Exposure Research Laboratory - Ecosystems Research Division
               Office of Research and Development (ORD)
           U.S. Environmental Protection Agency (U.S. EPA)
                       960 College Station Road
                      Athens, Georgia 30605-2700

                             706/355-8400

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Summary

The Weather Station Data Files contain meteorological data measured at 237
U.S. Weather stations for a period extending nominally from 1961 to 1990.
Exact collection dates vary by weather station. The files can be used with
the U.S. EPA PRZM and EXAMS models.  Each data set contains one "Daily
Values File" (.DVF), several "Hourly" values files (.Hnn), and one format
file (.TXT).

The "Daily Values File" (.DVF) lists approximately 30 years of daily
measurements including:
  
  Precipitation
  Pan Evaporation
  Temperature (mean)
  Wind Speed @10 meter
  Solar Radiation
  FAO Short Grass Eto
  Daylight Station Pressure
  Daylight Relative Humidity
  Daylight Opaque Sky Cover
  Daylight Temperature
  Daylight Broadband Aerosol
  Daylight Prevailing Wind Speed @10 meter
  Daylight Prevailing Wind Direction.

Each of the "Hourly" values files (.Hnn) lists one year's hourly measurements
including:

  Extraterrestrial Horizontal Radiation (Ra)
  Extraterrestrial Direct Normal Radiation
  Global Horizontal Radiation (Rs)
  Direct Normal Radiation
  Diffuse Horizontal Radiation
  Total Sky Cover
  Opaque_Sky_Cover
  Dry Bulb Temperature
  Dew Point Temperature
  Relative_Humidity
  Station_Pressure
  Wind_Direction
  Wind_Speed @10meter
  Horizontal Visibility
  Ceiling Height
  Observation Indicator
  Present_weather
  Precipitable Water
  Broadband Aerosol
  Snow Depth
  Days since last Snowfall
  Hourly Precipitation
  Eto, FAO Short Grass
  Ep, Class A pan Evaporation.

The format file (.TXT) specifies the file format of the daily and hourly 
value files and provides geographical information about the weather station.

Version 1.01 corrects errors in three daily value (*.dvf) files:
* W93738 (Sterling, VA) - added daily rainfall.
* W03937 (Lake Charles, LA) - deleted 1961- precipitation data not available
* W94860 (Grand Rapids, MI) - deleted 1961-1963 - precipitation data not available
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