ADVANCES IN THE SOUTH CHINA FFS HEAVY RAIN RESEARCH

Heavy rain (HR) or even exceptional heavy rain (EHR) usually takes place during the first flood season in South China in every April-June. In spring, cold air coming from north often brings about a normal HR over a large area in South China. However, EHR is mainly caused by tropical weather systems, the warm moist SW current from the Bay of Bengal-southern/central parts of the South China Sea,as well as the warm moist SE current from the NW Pacific Ocean. Investigations show that the fields cf flow and moisture in the lower troposphere play a more important role in HR rather than the potential height-temperature field. The ageostrophy and pulsation of SW jet stream in lower level have a distinct effect on the occurrence of HR and its non-uniform distribution in time-space. The sea/land breeze effect is obvious in South China. This is one of the important causes for very heavy rain to easily occur in South China and the different time of rain peak between coastal and interior regions.