Data on hourly or 3-hourly precipitation over the globe has recently become available from TRMM and other satellite measurements. This new data allows analyses of precipitation frequency, intensity and diurnal variations on a global scale and more detailed evaluation of model precipitation. We propose to study the precipitation characteristics and apply the results to evaluate climate models by analyzing several high-resolution precipitation products from TRMM (e.g., 3B42) and other satellite-based products such as the PERSIANN from UC, Irvine and CMORPH from NCEP/CPC.
The satellite observations will be compared with surface rain gauge and radar hourly measurements over the U.S. and rain gauge daily precipitation (including bias-corrected data) over land and 3-hourly weather reports of precipitation frequency over the globe. We will focus our analysis on (1) differences between satellite precipitation products with and without blending with infrared (IR) observations; (2) precipitation frequency and intensity derived from daily, 3-hourly, and hourly precipitation; and (3) the diurnal timing and amplitude in the hourly or 3-hourly products. Our goal is to quantify (a) whether the inclusion of the IR measurements improves the estimates of precipitation frequency, intensity and diurnal variations compared with microwave-only products; (b) what the strength and weakness of the various high-resolution products are; and (c) whether and how these relatively-new products can improve our knowledge about the spatial and temporal variations in precipitation frequency, intensity and diurnal cycle. The satellite data will then be applied to evaluate precipitation characteristics from coupled climate models with data archived at PCMDI.
Significant results from this proposal are expected to help evaluate TRMM and other satellite precipitation products, help design future precipitation missions, improve our knowledge about the various precipitation characteristics, and evaluate climate models. The project will also produce global monthly climatology of precipitation characteristics for community use.
1TRMM=Tropical Rainfall Measuring Mission 2PERSIANN=Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks 3CMORPH= Climate Prediction Center (CPC) morphing method
