The Atmospheric Radiation Measurement (ARM) Program conducted a Cloud Intensive Operational Period (IOP) in March 2000 that was the first-ever effort to document the 3-dimensional cloud field from observational data. Prior numerical studies of solar radiation propagation through the atmosphere in the presence of clouds have been limited by the necessity to use theoretical representations of clouds. Three-dimensional representations of actual clouds and their microphysical properties, such as the distribution of ice and water, had previously not been possible because instrumentation appropriate to the task was not available.

This case study presents data from 1 March 2000 to 31 March 2000 and covers a region from 25N to 45N latitude and from 120W to 80W longitude.

20 km ETA Model data are available here. For a description of the data format and source citation see the ETA model data readme. For a detailed description of the grid and coordinates, click here. The following variables are available:

• Dew point temp. data are available at 300, 400, 500, 700, 850, and 1000 mb.
• Volumetric soil moisture data are available at 0-10, 10-40, 40-100, 100-200 cm down.
• Soil temp. data are available at 0-10, 10-40, 40-100, 100-200, 300 cm down.
• Horizontal moisture divergence data are available at 850 and 950 mb.
• Geopotential height data are available at surface, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, 675, 700, 725, 750, 775, 800, 825, 850, 875, 900, 925, 950, 975, and 1000 mb.
• Relative humidity, Specific humidity, u wind and v wind data are available at 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, 675, 700, 725, 750, 775, 800, 825, 850, 875, 900, 925, 950, 975, and 1000 mb.
• Temperature data are available at 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375,400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, 675, 700, 725, 750, 775, 800, 825, 850, 875, 900, 925, 950, 975, 1000 mb, and at surface.
• Convective precipitation, Total precipitation, Land cover, Mean sea level pressure (ETA model), Moisture availability, Pressure and Soil moisture content data are available at a single level only.

You may:

• Ftp selected files (ftp://gcss-dime.giss.nasa.gov cd to pub/ARM-00/AWIP20)
• Or view other sources if available

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