West African Monsoon Dynamics and Eastern Equatorial Atlantic and Pacific SST Anomalies (1970-88)
West African Monsoon Dynamics and Eastern Equatorial Atlantic and Pacific SST Anomalies (1970-88)
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DOI：
10.1175/1520-0442-11.8.1874
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发表时间：
1998-08
影响因子：
4.9
通讯作者：
S. Janicot;A. Harzallah;B. Fontaine;V. Moron
中科院分区：
文献类型：
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作者：
S. Janicot;A. Harzallah;B. Fontaine;V. Moron
利用气象动力学大气GCM实验室研究了1970-1988年西非季风动力学与赤道东部大西洋和太平洋海温异常的关系。赤道东太平洋海温正异常主要与热带大西洋上空较大的东西向辐散环流有关，与西非的负降水异常相吻合。1972年、1976年、1982年和1983年的ENSO暖幕合成就是这种情况。相比之下，赤道东部大西洋海温正异常伴随着热带辐合带南移，萨赫勒地区为负降水异常，几内亚地区为正降水异常。1987年的情况就是这样。这一年的ENSO暖事件对西非季风动力学没有明显的影响。与东半球海温异常差异有关的纬向大气耦合。
Abstract The Laboratoire de Meteorologie Dynamique atmospheric GCM is used to investigate relationships between West African monsoon dynamics and SST anomalies in the eastern equatorial Atlantic and Pacific for the period 1970–88. Positive SST anomalies in the eastern equatorial Pacific, mainly associated with a larger east–west divergent circulation over the tropical Atlantic, are found to coincide with negative rainfall anomalies over West Africa. This is the case for the composite ENSO warm episodes of 1972, 1976, 1982, and 1983. By contrast, positive SST anomalies in the eastern equatorial Atlantic are accompanied by a southward shift of the intertropical convergence zone along with negative rainfall anomalies in the Sahel and positive rainfall anomalies in the Guinean region. This was the case in 1987. The ENSO warm event during this year had apparently no significant impact on West African monsoon dynamics. A zonal atmospheric coupling associated with differences of SST anomalies between the eastern...