JISAO data
Special Sensor Microwave / Imager (SSM/I) Precipitation
There are numerous algorithms for inferring precipitation from microwave signals. This page has two precipitation estimates developed by Ralph Ferraro, Norman Grody, and Fuzhong Weng at the NOAA NESDIS / Office of Research and Applications / Atmospheric Research and Applications Division. The estimates are:
estimatelandoceanperiod of record
"pr1"85 GHz scatteringscattering/emissionJul-Nov '87, '88-Jun '90, '92-96
"pr2"37 GHz scatteringemissionJul-Nov '87, '88-96

Annual total and standard deviation of monthly "pr1" precipitation (mm) 1988-89,1992-95
Statistics were calculated for the calendar years with complete data. The white regions in the top panel do not have estimates. Maximum annual total (standard deviation) rainfall > 3.5 m (> 20 cm / mon). The same statistics for "pr2" are linked here. (The associated PostScript file.) The "pr2" statistics are calculated for 1988-95. It is dangerous to compare statistics based on short and slightly different records. The "pr1" product would be useful for studies that require continuous data for the period beginning in 1988.

Climatological July rainfall (10cm/mon)
Based on the Julys in 1987-89, 1992-96 for the "pr1" data. The climatology for each month is available as a netCDF file (250 Kbytes).

Questions concerning the method should be directed to Ralph Ferraro.

The data:
"pr1" in netCDF format (2.5 Mbytes) (mm mon-1). Obtained in November 1996. Maps of "NaN"s are appended to the end of the file so that the file is for complete years. Errors in the netCDF file are due to Todd Mitchell.
"pr1" in compressed ASCII format (1.3 Mbytes). Obtained in November 1996. The organization of the data is described here, but you will have to modify the FORTRAN code to read the formatted data.
"pr2" in netCDF format (2.5 Mbytes) (mm mon-1). Obtained in December 1996. Maps of "NaN"s are appended to the end of the file so that the file is for complete years. Errors in the netCDF file are due to Todd Mitchell.
"pr2" in compressed ASCII format (1.3 Mbytes). Obtained in December 1996. The organization of the data is described here, but you will have to modify the FORTRAN code to read the formatted data.
The latest and greatest version of both estimates are available through NCDC. This data is written as FORTRAN "unformatted" format.

References:

  • Ferraro, R. R., F. Weng, N. C. Grody, and A. Basist, 1996: An eight-year (1987-1994) time series of rainfall, clouds, water vapor, snow cover, and sea ice derived from SSM/I measurements. Bull. Amer. Meteor. Soc., 77, 891-905.
  • online documentation for all SSM/I products

    December 1996
    Todd P. Mitchell (mitchell@atmos.washington.edu)
    JISAO data