广东“龙舟水”降水量成因分析

利用NCEP再分析资料、NOAA的OLR资料及GLDAS/NOAH的陆面资料对"龙舟水"前后的特征进行分析,结果表明:"龙舟水"期间,北半球中高纬度维持稳定的大气环流形势,有利于将冷空气引导至华南沿海;副热带高压加强西伸、孟加拉湾维持稳定的槽区,使得华南沿海暖湿气流加强,强暖湿气流为"龙舟水"过程的强降水提供充足的水汽和能量;旺盛的对流为降水提供动力条件;"龙舟水"过程前后的广东地区下垫面状况(陆面过程)的差异,对"龙舟水"期间该地区一些具体对流事件的启动和发展也有影响。

Causation Analysis of Dragon-Boat Precipitation in Guangdong Province

The characteristics of GDDBP were analyzed by using NCEP reanalysis data, NOAA OLR data and GLDAS/NOAH land surface state and flux parameters data. The results show that: during GDDBP process, Northern Hemisphere in the middle and high latitudes maintains a stable atmospheric circulation situation, which is conducive to the cold air into the South China coast; subtropical intensification and westward extension are strengthened, and a stable trough maintains in the Bay of Bengal, which bring strong warm and humid air to the South China coast, providing adequate moisture and energy for GDDBP; strong convections provide the dynamical conditions for the precipitation; and the difference of land-surface process has effect on a few concrete convection events during GDDBP.