Intercomparison and Validation of TRMM Rain Products

The Tropical Rainfall Measuring Mission (TRMM) satellite was launched in November 1997. It was the first joint satellite project between Japan and the United States of America. TRMM satellite has the first space precipitation radar on board. TRMM project has already provided high quality rain products for more than 6 years. The official TRMM rain retrieval algorithms have been made many improvements and been upgraded into the version 6 since they were initially released to public in early 1998. As the results, TRMM rain products will be soon moved into its version 6 products. Reprocess is already started in early April. The primary objective of this talk is to demonstrate that the quality of V6 TRMM rain products has been improved substantially against its previous versions. We will show the evolution of TRMM rain products and convergences of the V6 oceanic and continental monthly rainfall at 0.5°x0.5° and 5°x5° grid scales. The convergence of monthly rainfall is less than 10% for version 6 TRMM rain products of the 16-month testing datasets, in contrast to large than 25% for the version 4 products. Better results of intercomparison for V6 convective and stratiform rainfall will be discussed. The V6 rain products are validated with rain estimates from ground radar over TRMM validation sites. Finally, small discrepancies of V6 rain products among these algorithms are analyzed for their time-space distributions and physical explanations.