Revisiting the relationship between the South Asian summer monsoon drought and El Nino warming pattern
Revisiting the relationship between the South Asian summer monsoon drought and El Nino warming pattern
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重新审视南亚夏季季风干旱与厄尔尼诺变暖模式的关系
DOI：
10.1002/asl.740
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发表时间：
2017-04-01
影响因子：
3
通讯作者：
Zhu, Jiang
中科院分区：
文献类型：
--
作者：
Fan, Fangxing;Dong, Xiao;Zhu, Jiang
基于观测资料和再分析资料，探讨了厄尔尼诺增温与南亚夏季风干旱的关系。20世纪70年代末以后，东太平洋型厄尔尼诺-南方涛动（ENSO）与印度季风降水的负相关关系显著减弱，而中太平洋型厄尔尼诺-南方涛动（CP）与印度季风降水的负相关关系增强。此外，导致干旱的厄尔尼诺变暖模式也表现出与气候变化相关的显著年代际调制。分析结果表明，海温正异常的EP型厄尔尼诺和赤道太平洋中部增温最大的CP型厄尔尼诺都可能导致印度次大陆出现严重干旱。尽管太平洋平流层增温对赤道太平洋中部异常上升运动的驱动作用更大，从而导致南亚地区的异常沉降，但Walker环流异常上升和下降分支的位置和强度对热带海温异常的详细分布非常敏感，并由太平洋平流层增温和极平流层增温的竞争效应决定。
Based on the observational and reanalysis data, El Nino warming patterns associated with the South Asian summer monsoon droughts are investigated. While the inverse relationship between the eastern Pacific (EP) type of El Nino-Southern Oscillation (ENSO) and the Indian monsoon rainfall weakened significantly, the correlation between the central Pacific (CP) type of ENSO and the monsoon rainfall strengthened after the late 1970s. Moreover, the drought-producing El Nino warming pattern also exhibits a notable decadal modulation associated with the climate shift. The analysis results indicate that both the EP type of El Nino with positive sea surface temperature (SST) anomalies extended to the date line and the CP type of El Nino with the maximum warming located in the central equatorial Pacific may produce severe droughts over the Indian subcontinent. Although the CP warming is more effective in driving anomalous rising motion in the central equatorial Pacific and consequently producing anomalous subsidence over South Asia, the position and strength of the anomalous ascending and descending branches of the Walker circulation are sensitive to the detailed distributions of tropical SST anomalies and determined by the competing effects of the CP and EP warming.