The gauge-based precipitation analysis is applied to examine the performance of five selected high-resolution satellite precipitation estimates including the CMORPH of Joyce et al. (2004), the TRMM 3B42RT of Huffman et al. (2004), TRMM 3B42 of Huffman et al. (2006), the NRL blended product of Turk et al. (2004), and the PERSIANN of Hsu et al. (1997). Satellite estimates of the five products are integrated into fields of 0.25 deg lat/lon and 3-hourly resolution and compared with the gauge-based analysis for a period from April to August, 2005. Precipitation over the region in southern China is characterized by the evolution of East Asia monsoon from April to June, and by scattered convections in July to August. While our comparison covers a wide range of time and space scales, the focus of this work is the performance of the satellite products in depicting precipitation variations of sub-daily time scales. Our preliminary results showed the following:
1) All of the five satellite products are capable of capturing the overall spatial distribution and temporal variations patterns of precipitation reasonably well; 2) Performance of the satellite products varies for different regions and different precipitation regimes. In particular, bias changes with the monsoon evolution; 3) Diurnal cycle of precipitation derived from satellite estimates shows slightly different phase with that from the gauge observations; and 4) Satellite products tend to under-estimate the local maxima of precipitation.
Further work is underway to perform case studies and to extend the statistical analysis. Detailed results will be reported at the workshop.