Subtropical Indian Ocean SST dipole events and southern African rainfall
Subtropical Indian Ocean SST dipole events and southern African rainfall
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DOI：
10.1029/2000gl012735
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发表时间：
2001-06
影响因子：
5.2
通讯作者：
C. Reason
中科院分区：
文献类型：
--
作者：
C. Reason
大气环流模式（AGCM）被用来研究如何在南部非洲的区域大气环流和降雨响应最近观察到的偶极子在南印度洋副热带海表温度（SST）。观测表明，当马达加斯加南部的SST变暖，西澳大利亚州变冷时，非洲东南部大片地区的夏季降雨量就会增加。模式的结果表明，这种SST模式导致降水增加，通过加强辐合比平均空气在该地区。在西南印度洋的暖极，蒸发量增加，由于在该极产生的低压异常加强了向岸气流，这种潮湿的空气被平流输送到莫桑比克和南非东部。
An atmospheric general circulation model (AGCM) is used to examine how the regional atmospheric circulation and rainfall over southern Africa respond to a recently observed dipole in subtropical sea surface temperature (SST) over the South Indian Ocean. Observations suggest that when SST is warm to the south of Madagascar and cool off Western Australia, increased summer rains occur over large areas of southeastern Africa. The model results suggest that this SST pattern leads to increased rainfall via enhanced convergence of moister than average air over the region. Increased evaporation occurs over the warm pole in the South West Indian Ocean and this moist air is advected towards Mozambique and eastern South Africa as a result of the low pressure anomaly generated over this pole which strengthens the onshore flow.