冬季东亚副热带西风急流变化及其与海表温度的关系

利用1957-2002年ERA-40月平均再分析资料以及不同海域(全球、热带外、热带、热带印度洋—太平洋、热带印度洋和热带太平洋等)1950-2000年逐月观测海表温度,驱动NCARCAM3全球大气环流模式,根据模拟结果,分析讨论了冬季东亚副热带西风急流的变化特征及其与海表温度异常的关系.表明:1957-2001年冬季东亚副热带西风急流有增强的趋势,且具有准3 a的显著周期.热带海表温度异常,特别是热带太平洋海表温度异常对东亚副热带西风急流变化有重要影响,即当热带太平洋海表温度升高时,东亚副热带西风急流增强.

Variation of the east Asian subtropical westerly jet and its relation with sea surface temperature

By using the ERA-40 monthly mean reanalysis data from 1957 to 2002 and monthly observational SSTs, including global extra tropical, tropical oceans, Indian Ocean-Pacific in tropics, tropical Indian Ocean and tropical Pacific, from 1950 to 2000 as well as the experiments by the NCAR CAM3 as the global atmospheric model, the variations of the east Asian subtropical westerly jet (EAWJ) and its relation with SSTA are analyzed. The results show that EAWJ has the strengthening trend, whose intensity index has a significant period of 3 a from 1957 to 2001. SSTAs from tropical oceans, especially tropical Pacific, have significant impact on the variation of the EAWJ. When the SST from tropical Pacific rises, the EAWJ strengthens.