南海夏季风变化及其与全球大气和海温的关系

Variation of the South China Sea Summer Monsoon and Its Association with the Global Atmosphere Circulation and Sea Surface Temperature

本文分析了1948-2006年南海夏季风的年际变化,讨论了南海夏季风与全球气象要素场如环流、相对湿度、海表温度（SST）等的关系。结果表明：南海夏季风与全球各物理量之间有较好的大范围统计相关。选出了10个强南海夏季风年,8个弱南海夏季风年,利用合成分析研究了季风强、弱年的环流和SST特征及其差异,结果表明南海夏季风强弱年各特征量之间存在显著差异。尤其表现在SST上,强弱季风年不仅在夏季东印度洋-西太平洋区域有明显差异,并且前期春季此区域的SST与南海夏季风有持续的显著负相关,可以作为南海夏季风强度变化的一个预报因子。

Based on the normalized monsoon index presented by Li and Zeng （2002）, the interannual variation of the South China Sea summer monsoon （SCSSM） during 1948 - 2006 and its relations with the global atmospheric circulation and sea surface temperature （SST） are studied. The results indicate that there exist significant statistical correlations over large regions between the SCSSM and the global zonal winds, relative humidity and SST, etc. Ten strong SCUM monsoon years and eight weak SCSSM monsoon years are chosen to identify the differences in atmospheric circulation and SST between the strong and weak SCSSM years. The composite analyses show significant differences in various variables between the strong and weak SCSSM years. Especially in the SST fields, the differ- enees are not only obvious in the Eastern Indian Ocean- the Western Pacific （EIOWP） in summer, but there is also a signifieant negative correlation between the SCSSM index （SCSSMI） and EIOWP SST in the prior spring which is a substantial relation. The latter could be taken as an indicator of the SCSSM variation.