华南暖季极端降水与气温的对应关系

利用华南地区1966—2005年5—10月台站小时降水和日降水以及气温观测资料，分析了极端降水与气温的对应关系。结果表明，气温低于25℃时，日极端降水强度与小时极端降水强度均随气温升高而升高，且越极端的降水出现向两倍Clausius-Clapeyron (CC)变率转换的气温越低；气温高于25℃时，日极端降水强度和小时极端降水强度出现不同程度的下降，其中前者下降更为显著。考察降水持续时长发现，气温高于25℃时，华南地区小时极端降水随气温的下降主要由短持续性降水所贡献；气温高于28℃时几乎无长持续性降水发生。

An Analysis on Relation Between Warm Season Precipitation Extremes and Surface Air Temperature in South China

Hourly station rain gauge data over South China during 1966-2005 were used to analyze the corresponding relation between precipitation extremes and surface air temperature in the warm season (May to October). The results show that both daily and hourly precipitation extremes in South China increase with temperature rise, and more extreme events show an earlier transition to the two-times Clausius-Clapeyron (CC) relationship. Meanwhile, daily as well as hourly precipitation extremes, present a decrease after the peak point around 25℃, and the decrease of daily precipitation extremes appears to be much more intense. In view of rainfall durations, hourly precipitation extremes are presented by short duration and long duration precipitations individual. Results show that the dramatic decrease of hourly rainfall intensities around 25℃ is mainly caused by short duration precipitation, and long duration precipitation extremes seldom occur when surface air temperature breaks 28℃.