A report of the field operations and early results of the South China Sea Monsoon Experiment (SCSMEX)

The South China Sea Monsoon Experiment (SCSMEX) is an international field e xperiment with the objective to better understand the key physical processe s for the onset and evolution of the summer monsoon over Southeast Asia and southern China aiming at improving monsoon predictions. In this article, a description of the major meteorological observation platforms during the i ntensive observing periods of SCSMEX is presented. In addition, highlights of early results and discussions of the role of SCSMEX in providing valuabl e in situ data for calibration of satellite rainfall estimates from the Tro pical Rainfall Measuring Mission are provided. Preliminary results indicate that there are distinctive stages in the onset of the South China Sea mons oon including possibly strong influences from extratropical systems as well as from convection over the Indian Ocean and the Bay of Bengal. There is s ome tantalizing evidence of complex interactions between the supercloud clu ster development over the Indian Ocean, advancing southwest monsoon flow ov er the South China Sea, midlatitude disturbances, and the western Pacific s ubtropical high, possibly contributing to the disastrous flood of the Yangt ze River Basin in China during June 1998.