92nd American Meteorological Society Annual Meeting (January 22-26, 2012)

Wednesday, 25 January 2012: 11:30 AM
Investigating Changes in Rain Rate Distributions Using a New Long-Term Precipitation Dataset From SSM/I
Room 257 (New Orleans Convention Center )
Wesley Berg, Colorado State Univ., Fort Collins, CO; and C. Kummerow, M. R. P. Sapiano, and D. Randel

The Special Sensor Microwave/Imager (SSM/I) has flown on board six of the operational Defense Meteorological Satellite Program (DMSP) spacecraft beginning with F08 in July of 1987 and continuing through the present on F15. Data from these sensors have been used to produce long-term datasets of a number of geophysical parameters including global estimates of precipitation. Because these sensors were designed for operational use, however, a number of issues have limited the usefulness of these data for many climate applications. These include quality control issues, particularly in the early data record, insufficient information on changes in the view angle between sensors and over time, calibration between sensors, and limitations of the retrieval algorithms to accurately represent differences in rainfall statistics between regimes. An updated precipitation algorithm, referred to as GPROF 2010, developed for application to a constellation of radiometers in the Global Precipitation Measurement (GPM) Mission and a separate effort to create an intercalibrated fundamental climate data record (FCDR) of the brightness temperature data from these six sensors has resulted in the production of a new long-term global precipitation dataset. This new SSM/I precipitation dataset provides much better consistency between sensors as well as significantly improved estimates of precipitation over oceans, particularly light rain, while better capturing regime-dependent differences. We subsequently use this new dataset to investigate regional and time-dependent changes in rain rate distributions, which can change significantly even though the total rain volume may show little or no change.

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