Maintenance of the Midtropospheric North African Summer Circulation: Saharan High and African Easterly Jet
Maintenance of the Midtropospheric North African Summer Circulation: Saharan High and African Easterly Jet
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北非夏季对流层中层环流的维持：撒哈拉高压和非洲东急流
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
Tsing‐Chang Chen
中科院分区：
文献类型：
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作者：
Tsing‐Chang Chen
摘要 北非夏季对流层中层环流的显着特征是撒哈拉高压，其南缘被非洲东风急流（AEJ）包围。就像一个主要的季风环流一样，撒哈拉高压与东边的北非辐散中心和西边的东大西洋辐合中心并列。与主要季风环流不同，这些明显的对流层中层环流成分被青藏高原西部覆盖。鉴于撒哈拉高压和非洲东急流在北非夏季环流中所发挥的独特作用，本文致力于探索这两个对流层中层环流要素的维持机制。这项工作的主要发现总结如下： 从速度势维持方程来看，乍得-苏丹地区的北非发散中心是通过撒哈拉热-低加热建立的垂直差异加热来维持的。
Abstract The conspicuous feature of the midtropospheric North African summer circulation is the Saharan high surrounded on its southern rim by the African easterly jet (AEJ). Like a major monsoon circulation, the Saharan high is juxtaposed with the North African divergent center to the east and the eastern Atlantic convergent center to the west. Different from a major monsoon circulation, these pronounced midtropospheric circulation components are overlaid by the western part of the Tibetan high. Because of the unique roles played by the Saharan high and the African easterly jet in the North African summer circulation, an effort is made to explore maintenance mechanisms of these two midtropospheric circulation elements. Major findings of this effort are summarized as follows: In terms of the velocity potential maintenance equation, it is shown that the North African divergent center over the Chad–Sudan region is maintained by the vertical differential heating established by the Saharan thermal-low heating...