ENSO事件对东亚副热带西风急流影响的诊断分析  

The diagnostic analysis of the impact of ENSO events on East Asia subtropical westerly jet

作　　者：黄兴春[1] 江静[1] 

机构地区：[1]南京大学大气科学系,南京210093

出　　处：《气象科学》2008年第1期15-20,共6页Journal of the Meteorological Sciences

基　　金：国家自然科学基金项目(40233028)

摘　　要：本文利用NCEP/NCAR月平均再分析资料,用合成分析和相关分析方法就ENSO事件对东亚副热带西风急流的影响进行诊断分析。主要结论为:ElNino年冬季200hPa东亚副热带西风急流主要在急流出口区纬向风有正距平,急流增强东扩。而LaNina年冬季急流在急流出口区纬向风有负距平,急流减弱西移。ElNino年夏季急流增强,主要在急流区内的偏南部纬向风有正距平。LaNina年夏季急流减弱,主要在急流区内的偏南部纬向风有负距平;相关分析表明东亚副热带西风急流冬、夏季纬向风与热带中东太平洋冬、夏季海表温度有显著的相关。研究表明,ENSO年冬、夏季对流层中上层有较大的气温异常,并由此产生大的经向温度梯度的异常,这可能是ENSO事件影响东亚副热带西风急流的原因之一。In this paper we analyse the impact of ENSO events on East Asia subtropical westerly jet （EAWJ） at 200 hPa by using methods of synthesizing and correlation in terms of NCEP/NCAR reanalysis data. The results show that EAWJ in winter is stronger than normal in El Nino years, while it is weaker in La Nina years. The remarkable difference locates at the exit region of EAWJ, which is statistically significant at 5% significance level. In summer, the zonal stronger than normal during El Nino, but weaker during winds in the eastern and southern of EAWJ are La Nina, which are also significant at 5% level. The ENSO-related SSTs result in abnormalities of temperatures at 500 - 200 hPa, which cause corresponding variations in meridional gradients of temperature. Perhaps it is one of the reasons why ENSO impacts on EAWJ.

关 键 词：ENSO 东亚副热带西风急流 海表温度 纬向风 经向气温梯度 

分 类 号：P466[天文地球—大气科学及气象学]