Abstract In this study, observational data together with the simulations from a high-resolution numerical ocean model are used to identify the processes responsible for the anomalous warm sea surface temperature (SST) over the equatorial Indian Ocean during late spring/early summer in 2007. Our analysis suggests that the SST in the western equatorial Indian Ocean (WEIO) remained unusually warm owing to the combined influence of the wind induced and reflected Rossby waves in the equatorial Indian Ocean. Anomalous westerly wind burst in the equatorial Indian Ocean in early April generated an eastward propagating downwelling Kelvin wave, which got reflected from the eastern boundary as a downwelling Rossby wave and propagated to the WEIO. The easterlies appeared during the second fortnight of April generated another downwelling Rossby wave, which also propagated to the WEIO. Thus a couple of downwelling Rossby waves, reflected and direct wind induced, propagated to the WEIO, deepened the thermocline and prohibited cooling in the WEIO during the early months of summer monsoon season. This study demonstrates the importance of the equatorial winds and associated oceanic dynamics in modulating the SST variability in the WEIO.

中文翻译：

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2007 年西赤道印度洋异常变暖：海洋动力学的作用

摘要 本研究利用观测数据和高分辨率数值海洋模型的模​​拟结果，确定了 2007 年春末夏初赤道印度洋暖海面温度异常的过程。我们的分析表明，由于赤道印度洋中风引起和反射的罗斯比波的综合影响，西赤道印度洋 (WEIO) 的海温保持异常温暖。4 月初赤道印度洋爆发的异常西风产生了一个向东传播的向下流开尔文波，它从东部边界反射为向下流罗斯比波并传播到 WEIO。东风出现在四月的第二个两周，产生了另一个向下涌的罗斯比波，这也传播到了WEIO。因此，在夏季季风季节的最初几个月，几个向下涌的罗斯比波，反射和直接风引起，传播到 WEIO，加深了温跃层并阻止了 WEIO 的冷却。这项研究证明了赤道风和相关海洋动力学在调节 WEIO 海温变化中的重要性。