夏季广东降水异常变化与夏季风

VARIATIONS OF RAINFALL ANOMALIES IN GUANGDONG ASSOCIATED WITH SUMMER MONSOON

关键词:  降水异常  夏季风  广东

Key words:  Rainf allanomalies  Summer monsoon  Guangdong

摘要:

利用广东省36个地面站降水量资料和NCEP850hPa再分析资料,采用相关分析和合成对比分析方法,探讨了广东降水变化与夏季季风活动的关系。发现广东夏季降水量变化与南海北部西南风大小成显着正相关,但并不能由此得出南海北部西南季风强广东降水多的结论。前汛期(4-6月),西南季风可以给广东带来降水,但降水的变化与西南季风强度变化关系不显着,5-6月份甚至出现热带西南季风弱广东降水反而强的情况,其主要的影响来自于副热带季风的加强。后汛期(7-9月),当西南季风在南海中北部地区加强,副热带季风对广东影响减弱时,广东降水增大。

Abstract:

Using NCEP reanalyzed data of 850hPa and rainfall data in Guangdong, the variations of rainfall anomalies in Guangdong associated with summer monsoon are investigated by correlation analysis and composite and contrast methods. The significant correlation between the rainfall and southwest winds over the north part of South China Sea(NPSCS)has been found. In the first stage of rain period in Guangdong(April to June), the summer monsoon can bring precipitation to Guangdong, but the relationship between the rainfall anomaly and the intensity of summer monsoon is not significant. The anomalously more rainfall in Guangdong happens in the period of the weaker tropical monsoon and strong subtropical monsoon during May and June. In the second stage of rain period(July to September), the rainfall is greater with stronger southwest monsoon in NPSCS and weaker subtropical southeast monsoon.