Authors: Qian Liu*, George Mason University
Topics: Earth Science
Keywords: TRMM 3B42, Rain Frequency, Mean Rain rate, Conditional Rain rate, convective precipitation
Session Type: Paper
Start / End Time: 1:10 PM / 2:50 PM
Room: Buchanan, Marriott, Mezzanine Level
Presentation File: No File Uploaded
The spatial-time mean rain rate (MR) can be characterized by the rain frequency (RF) and the conditional rain rate (CR). We analysed the TRMM Multi-satellite Precipitation Analysis (TMPA) 3 hourly 0.25degree gridded data for the period 1998-2016. Over the TMPA domain, the mean rain rate (MR), rain frequency (RF) and conditional rain rate (CR) are 0.12 mm/hr, 10.5%, and 1.14 mm/h. The rain frequency for CMORPH at the same resolution is 13.8%. In the Northern Hemisphere the MR, RF and CR are 0.14 mm/h, 13.15%, and 1.11 mm/h over the ocean and 0.08 mm/h, 5.42% and 1.55 mm/h over land. In the Southern Hemisphere, they are 0.11 mm/h, 11.25% and 0.97 mm/h over ocean and 0.14 mm/h, 8.55% and 1.63 mm/h over land, in that order. The time series of RF (CR) show significant decreasing (increasing) trends, while no significant trend in MR. The RF (CR) of the tropics decreased (increased) by 4.9% (0.54mm/hr) over 18.5 years. Convective rainfall in the TRMM gridded data showed that about 5.1%, 14.0%, and 81% of the rainfall areas are deemed convective, stratiform, and other types while the convective rain rate is 0.06 mm/h which is about 50% of the global rainfall. If we consider the period 2001 to 2014, the RF of convective rainfall increases while the convective CR also increases.