南方涛动年际变化与夏季亚澳季风环流及海洋性大陆区域气候异常的联系

Interannual variation of Southern Oscillation and its association with Asia-Australian monsoon circulation and regional climate anomaly in the Maritime Continent during boreal summer

摘要:

利用美国NOAA卫星观测的SOI（Southern Oscillation Index，南方涛动指数）资料以及NCEP/NCAR、CMAP月平均资料，采用相关分析等方法，研究了南方涛动年际变化与夏季亚澳季风环流及海洋性大陆区域气候异常的联系。结果表明：南方涛动具有显著的年际变化特征，这种年际变化对夏季亚澳季风区及海洋性大陆区域的环流、降水及温度异常有重要影响。当SOI正位相时，赤道以南的澳大利亚东部地区以及西北太平洋海域高层为气旋，低层为反气旋，赤道地区的东部太平洋低层为辐散中心，高层为辐合中心，有利于下沉运动维持；加里曼丹岛附近低层辐合，高层辐散，有利于上升运动维持；海洋性大陆地区降水为显著的正异常，东亚地区降水存在较弱的正异常；海洋性大陆地区以及我国青藏高原到东海一带温度为正异常，孟加拉湾及印度半岛区域温度为负异常。

Abstract:

Based on the Southern Oscillation Index(SOI) from NOAA and the monthly mean data from NCEP/NCAR Reanalysis and CMAP,using correlation analysis and other methods,this paper investigated the interannual variation of SO(Southern Oscillation) and its association with Asian-Australian monsoon circulation and regional climate variation in the Maritime Continent during boreal summer.Results show that SO has significant interannual variation characteristics,which has important influences on the circulation,precipitation and temperature anomalies over Asian-Australian monsoon region and the Maritime Continent during boreal summer.When SOI is in positive phase,there is a cyclonic circulation in the upper troposphere and an anticyclonic circulation in the lower troposphere over eastern Australia and eastern sea area south of the equator.As the result the lower tropospheric divergence and upper tropospheric convergence over the region of Pacific north of the equator facilitate the maintenance of descending motion.The lower tropospheric convergence and upper tropospheric divergence near Kalimantan Island are favorable for the maintenance of ascending motion.The precipitation anomalies are significant positive in the maritime continent and weak positive in eastern China.The temperature anomalies are positive in the maritime continent and from Tibetan Plateau to East China Sea and negative over Bay of Bengal and Indian Peninsula.The results are helpful for our deeply understanding the influence mechanism of SO on regional climate variation.