ENSO循环的两个不同位相期印度洋海表温度异常的特征分析

The variable characteristics analysis of SSTA over the Indian ocean during the two phasea of ENSO cycle

通过对 ENSO循环的两个不同位相中印度洋地区海表温度变化特征的分析 ,指出印度洋地区的海温变化与赤道东太平洋地区的海温变化有较好的相关关系 ,是ENSO循环的重要组成部分。对应于赤道东太平洋暖位相期 ,印度洋地区的海温分布为东冷西暖 ;与此相反 ,在赤道东太平洋冷位相期 ,印度洋地区的海温分布为东暖西冷。进一步的分析还发现 ,印度洋东、西部地区海温变化纬向差异最明显的区域位于印度洋赤道以南 0～ 2 5°S附近 ,且这种差异具有明显的年季变化特征 ,在整个夏季风期间差异较大 ,而冬季风期间较小 ,其中冷位相期间的纬向差异比暖位相期间的纬向差异大。代表印度洋纬向差异的 IDM(偶极指数 )变化与赤道东太平洋地区的海温变化有很好的正相关关系。

By analyzing the variable characteristics of SST in the Indian Ocean during different phases of ENSO cycle,it is found that the correlation of the variation of SST between in the Indian Ocean and in eastern equatorial Pacific is significant,and the variation of SST in the Indian Ocean is an important component of ENSO cycle.The SST pattern in the Indian Ocean is warm in the western part and cold in the eastern part when SST in the eastern equatorial Pacific is warm,and v.v.Furthmore,the results showed that the most significant area of difference of SSTA between in the Western and Eastern Indian Ocean is in 0～25°S.It's interannual and seasonal change is significant.The zonal difference of SST variation in the Indian Ocean during summer monsoon season is more significant than that during winter monsoon season,and the difference during cold phases is larger than that during warm phases.The correlation coefficient is 0.55 between Dipole Mode Index in the Indian Ocean and SSTA in the eastern equatorial Pacific.