赤道太平洋-印度洋海温异常综合模与次表层海温异常

The preliminary research of equatorial Pacific-Indian Ocean temperature anomaly mode and subsurface ocean temperature anomalies

通过对1958—2001年的SODA海温资料进行经验正交函数分解,得到了太平洋-印度洋海温异常综合模态,该模态在海表及次表层的时空演变特征的分析表明,在赤道西印度洋、中东太平洋的海温偏高(低)时,赤道西太平洋、东印度洋的海温偏低(高)。该综合模态既有年际变化特征,还有年代际变化特征,在20世纪70年代中后期由以负指数为主转变为以正指数为主。对1958—2001年强正、负指数事件合成分析结果得知,综合模也存在着显著的年变化特征,在2—4月份偏弱,最强出现在10月份。西太平洋暖池次表层与赤道东太平洋次表层、赤道东印度洋次表层与西印度洋次表层有一种反位相的变化。次表层海温异常在东太平洋、西印度洋分别沿着南北纬10°左右向西太平洋、东印度洋传播并向赤道扩展,西太平洋、东印度洋的次表层海温异常则分别沿赤道向东太平洋、西印度洋传播汇聚。

This paper further studies the equatorial Pacific-Indian Ocean temperature anomaly mode on the sea surface and subsurface with the application of the empirical orthogonal function （EOF） analysis of SODA temperature data from 1958 to 2001. Temperature anomalies in the equatorial western Indian Ocean and eastern Pacific and that in the equatorial eastern Indian Ocean-western Pacific are inverse. The wavelet analysis shows that this mode has annual, interannual and interdecadal variability. Results of composite analyses disclose that anomalies of subsurface ocean temperature in the equatorial eastern Indian Oceanwestern Pacific and their propagations along the thermocline have direct correlations with temperature anomalies in the equatorial western Indian Ocean and eastern Pacific. The anomalies of subsurface ocean temperature in the equatorial western Indian Ocean propagate to the eastern Indian Ocean, and anomalies in the equatorial eastern Pacific propagate to the western Pacific along about 10°N and 10°S, at the same time, the temperature anomalies in the equatorial eastern Indian Ocean western Pacific propagate westwards to the western Indian Ocean and eastwards to the eastern Pacific along the equator respectively.