Relationship of Sahel Precipitation and Atmospheric Centers of Action
Relationship of Sahel Precipitation and Atmospheric Centers of Action
复制标题
萨赫勒降水量与大气作用中心的关系
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
N. Riemer
中科院分区：
文献类型：
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作者：
S. Hameed;N. Riemer
在最近的文献中，与萨赫勒干旱有关的动态引起了相当大的关注。本文使用大气作用中心的范式来评估萨赫勒降水，即主导区域环流的延长的半永久性高点和低点，并且在海平面压力模式中很明显。研究发现，亚速尔高地和南亚低地的变化对萨赫勒地区降水有显著影响。具体来说，萨赫勒地区7月至9月的降雨量变化中约有50%是由亚速尔群岛高经度位置和南亚低压的变化来解释的。相比之下，南方涛动对萨赫勒降水的贡献相对较小。本文的结果表明，气候模式在模拟萨赫勒地区降雨变率方面的一个关键检验是该模式模拟南亚低地和亚速尔高原动态的准确性。
The dynamics associated with drought in the Sahel have attracted considerable attention in the recent literature. This paper evaluates Sahel precipitation using the paradigm of the atmospheric centers of action, that is, the extended semipermanent highs and lows that dominate regional circulations and are evident in sea level pressure patterns. We find that Sahel precipitation is significantly influenced by changes in the Azores High and the South Asia Low. Specifically, about 50 percent of the variance of July to September rainfall over the Sahel is explained by changes in the Azores High Longitude position and South Asia Low pressure. In contrast, the contribution of the Southern Oscillation to Sahel precipitation is smaller in comparison. Results presented in this paper suggest that a key test for a climate model in simulating variability of Sahel rainfall is the accuracy with which the model simulates the dynamics of South Asia Low and the Azores High.