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TRMM Version 7 Level 3 Gridded Monthly Accumulations of GPROF Precipitation RetrievalsIn July 2011, improved versions of the retrieval algorithms were approved for TRMM. All data starting with June 2011 are produced only with the version 7 code. At the same time, version 7 reprocessing of all TRMM mission data was started. By the end of August 2011, the 14+ years of the reprocessed mission data became available online to users. This reprocessing provided the opportunity to redo and enhance upon an analysis of V7 impacts on L3 data accumulations that was presented at the 2010 EGU General Assembly. This paper will discuss the impact of algorithm changes made in th GPROF retrieval on the Level 2 swath products. Perhaps the most important change in that retrieval was to replacement of a model based a priori database with one created from Precipitation Radar (PR) and TMI brightness temperature (Tb) data. The radar pays a major role in the V7 GPROF (GPROF2010) in determining existence of rain. The level 2 retrieval algorithm also introduced a field providing the probability of rain. This combined use of the PR has some impact on the retrievals and created areas, particularly over ocean, where many areas of low-probability precipitation are retrieved whereas in version 6, these areas contained zero rain rates. This paper will discuss how these impacts get translated to the space/time averaged monthly products that use the GPROF retrievals. The level 3 products discussed are the gridded text product 3G68 and the standard 3A12 and 3B31 products. The paper provides an overview of the changes and explanation of how the level 3 products dealt with the change in the retrieval approach. Using the .25 deg x .25 degree grid, the paper will show that agreement between the swath product and the level 3 remains very high. It will also present comparisons of V6 and V7 GPROF retrievals as seen both at the swath level and the level 3 time/space gridded accumulations. It will show that the various L3 products based on GPROF level 2 retrievals are in close agreement. The paper concludes by outlining some of the challenges of the TRMM version 7 level 3 products.
Document ID
20120009887
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Authors
Stocker, E. F. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Kelley, O. A. (George Mason Univ. Greenbelt, MD, United States)
Date Acquired
August 25, 2013
Publication Date
April 22, 2012
Subject Category
Meteorology And Climatology
Report/Patent Number
GSFC.CPR.00168.2012
Meeting Information
Meeting: European Geosciences Union General Assembly 2012
Location: Vienna
Country: Austria
Start Date: April 22, 2012
End Date: April 27, 2012
Distribution Limits
Public
Copyright
Public Use Permitted.

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