波浪输运与赤道印度洋海温异常的关系

Relationship between Stokes Transport and SST Anomalies of the Equatorial Indian Ocean

本文利用海浪月平均数据和海表面温度(Sea Surface Temperature,SST)数据,使用多种统计分析方法,研究了波浪诱导的大尺度水体输运与赤道印度洋海表面温度异常的关系,结果显示印度洋波浪输运与赤道印度洋SST异常有很强的相关性。通过经验正交分解的方法分析了波浪输运时空特征及其振荡主周期,发现:其主要模态的变化周期与印度洋偶极(Indian Ocean Dipole,IOD)指数的振荡周期基本相同。IOD正事件爆发前,波浪输运持续向IOD2区(90°E-110°E,10°S-EQ)输运冷水;IOD负事件爆发前,波浪输运持续向IOD1区(50°E-70°E,10°S-10°N)输运冷水。并且在波浪输运提前正IOD事件6个月,提前负IOD事件2-3个月时,二者的相关系数达到最大,分别为0.5和0.55。

Based on the monthly average wave data and the Sea Surface Temperature(SST),the relationship between wave-induced large-scale Stokes transport and the SST anomalies in the Equatorial Indian Ocean is studied using statistical methods.It is suggested that the stokes transport is strongly related to SST anomalies in the tropical Indian Ocean.The temporal and spatial characteristics of stokes transport and the primary period in the tropical Indian Ocean are analyzed by the empirical orthogonal decomposition method.The analysis shows that the main periods are roughly similar with the oscillation cycle of IOD(Indian Ocean Dipole)index.Stokes transport transfers continuously the cold water to IOD-2 region(90°E-110°E,10°S-EQ)before the positive IOD event breaks,and transfer the cold water continuously to IOD-1 region(50°E-70°E,10°S-10°N)before the negative IOD event outbreaks.Lead-lag correlation shows that the SST anomalies lag the stokes transport 6 months in the positive IOD event and 2-3 months in the negative IOD event,and the correlation coefficients are 0.5 and 0.55 respectively.