Observed Precipitation Validation

The table below illustrates validation of the precipitation products available to GLDAS. The various products are compared with the Higgins gauge and NEXRAD ground radar datasets (NOAA) which are considered "truth". The evaluated products are satellite derived precipitation estimates from the Naval Research Laboratory (both Geostationary IR and merged microwave (SSMI/TRMM/AMSUB) products; provided by Joe Turk), NASA's TRMM Real-time Multi-Satellite Precipitation Analysis (provided by George Huffman), the University of Arizona's PERSIANN dataset, CMORPH (provided by John Janowiak), model based products from NASA/GMAO (GEOS4) and NOAA/NCEP (EDAS and GDAS), and a merged dataset (gauge/satellite) from the Air Force Weather Agency (AFWA; AGRMET). A surface map is also provided to illustrate in general terms the synoptic environment in which the precipitation occurred.

In the table below, the first row shows a 7 day comparison while the remaining rows show daily comparisons for each of the last seven days. The table shows total precipitation (mm) over each type of period (daily or weekly). The daily comparisons range from 12 UTC to 12 UTC. The percentage of data out of what is possible during the time period is given for reference. Any missing data is not necessarily due to the fact that the data from the original source was not created but may be due to local data transfer problems. Contact the original data providers (NASA, NOAA, NRL, Univ. of Arizona, and AFWA) if you would like to view time periods in which data is missing at this site.

***** The PERSIANN data is currently not available at this site due to a transfer of the PERSIANN precipitation system from the University of Arizona to the University of California at Irvine. The Persiann data at this site will be resumed when this migration is complete *****

***** The GEOS4 data is currently not available from the Global Modeling and Assimilation Office (GMAO). When production resumes, images from this data will again be available at this site *****

Time Period	NRL Infrared Precipitation	NRL Microwave Precipitation	NASA Merged Precipitation	PERSIANN Precipitation	CMORPH Precipitation	AGRMET Precipitation	Higgins Gauge Precipitation	Stage II Nexrad	EDAS Model Precipitation	GEOS Model Precipitation	GDAS Model Precipitation	Surface Weather Map
	Data=100 %	Data=96 %	Data=100 %	Data=100 %	Data=100 %	Data=0 %	Data=100 %	Data=100 %	Data=93 %	Data=100 %	Data=100 %	Data=N/A
09/01 - 09/07
	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=0 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=N/A
sep 07, 2004
	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=0 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=N/A
sep 06, 2004
	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=0 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=N/A
sep 05, 2004
	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=0 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=N/A
sep 04, 2004
	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=0 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=N/A
sep 03, 2004
	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=0 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=100 %	Data=N/A
sep 02, 2004
	Data=100 %	Data=75 %	Data=100 %	Data=100 %	Data=100 %	Data=0 %	Data=100 %	Data=100 %	Data=50 %	Data=100 %	Data=100 %	Data=N/A
sep 01, 2004

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LDAS Web Page Developed and Maintained at NASA/GSFC

Jon Gottschalck: jgottsch@hsb.gsfc.nasa.gov Brian Cosgrove: Brian.Cosgrove@gsfc.nasa.gov Paul R. Houser: Paul.Houser@gsfc.nasa.gov