Analysis of African Easterly Wave Structures and Their Role in Influencing Tropical Cyclogenesis
Analysis of African Easterly Wave Structures and Their Role in Influencing Tropical Cyclogenesis
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非洲东风波结构及其影响热带气旋作用的分析
DOI：
10.1175/2009mwr2760.1
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发表时间：
2010
影响因子：
3.2
通讯作者：
Kevin Tyle
中科院分区：
文献类型：
--
作者：
S. Hopsch;C. Thorncroft;Kevin Tyle
摘要利用1979 - 2001年欧洲中期天气预报中心（ECMWF）再分析（ERA-40）资料和卫星亮温资料，对非洲东风波（AEWs）在大西洋发展成命名热带气旋与非发展中AEWs的合成结构进行了对比分析。发展中的AEW的特点是在到达西非海岸前两天有一个更独特的冷芯结构。当它们向西移动时，几内亚高地地区附近的对流活动进一步增加。与此同时，AEW槽在低层增加了涡度，这与它到达海洋之前向更暖心结构的转变一致。当AEW移动到低压槽上方时，海洋对流维持在低压槽中，这与观测到的热带气旋生成相一致。未发展的空中预警在到达海岸前有类似的演变，只是振幅较弱，几内亚高地地区的对流活动较少。非发展中的空中预警复合材料…
Abstract Composite structures of African easterly waves (AEWs) that develop into named tropical cyclones in the Atlantic are compared and contrasted with nondeveloping AEWs using the 40-yr ECMWF Re-Analysis (ERA-40) data and satellite brightness temperature between 1979 and 2001. Developing AEWs are characterized by a more distinctive cold-core structure two days before reaching the West African coast. As they move westward, the convective activity increases further in the vicinity of the Guinea Highlands region. At the same time the AEW trough increases its vorticity at low levels consistent with a transformation toward a more warm-core structure before it reaches the ocean. As the AEW moves over the ocean convection is maintained in the trough, consistent with the observed tropical cyclogenesis. The nondeveloping AEW has a similar evolution before reaching the coast except that the amplitudes are weaker and there is less convective activity in the Guinea Highlands region. The nondeveloping AEW composite...