1. Precipitation Intensity and Cloud Physics
Brad Eck
April 26, 2007

2. Data Sources Precipitation Intensity Cloud Physics
North American Regional Reanalysis (NARR)
netCDF (thanks to Cedric)
Units: kg/m^2/s  mm/s
Cloud Physics
Moderate Resolution Imaging Spectrometer (MODIS)
Optical Thickness

3. Optical Thickness
“…a measure of how opaque a medium is to radiation passing through it.”
“The (dimensionless) line integral of the absorption coefficient…along any path in a … medium.”

4. Source: King et. al., “Remote sensing of cloud, aerosol, and water vapor properties from the Moderate Resolution Imaging Spectrometer (MODIS),” IEEE Trans. Geosci. Remote Sens. 30, 2-27 (1992).

5. Sprechen Sie Englisch?
Optical thickness combines droplet size, water content and cloud height to give a normalized cloud size
Bigger clouds should have a higher precipitation intensity

10. May 2006