Are Tropical Cyclones Less Effectively Formed by Easterly Waves in the Western North Pacific than in the North Atlantic
Are Tropical Cyclones Less Effectively Formed by Easterly Waves in the Western North Pacific than in the North Atlantic
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DOI：
10.1175/2008mwr2149.1
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发表时间：
2008-11
影响因子：
3.2
通讯作者：
Tsing‐Chang Chen;S. Wang;M. Yen;A. Clark
中科院分区：
文献类型：
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作者：
Tsing‐Chang Chen;S. Wang;M. Yen;A. Clark
摘要 据观察，北大西洋（~60%）源自东风波的热带气旋比例远高于北太平洋西部（10%~20%）。两个洋盆之间之所以存在这种差异，是因为北太平洋西部的大多数（71%）热带气旋发生在季风环流演变而来的有利天气环境中。由于北大西洋没有类似于北太平洋西部的季风槽刺激季风环流形成，因此与北太平洋西部相比，热带气旋的大部分是由东风波直接引起的。这项研究还分析了在北太平洋西部形成热带气旋的东风波的百分比。通过仔细地将东风波与源于热带上对流层槽 (TUTT) 的上层涡旋产生的低对流层扰动分开，观察到 25% 的东风波在该地区形成热带气旋。
Abstract It has been observed that the percentage of tropical cyclones originating from easterly waves is much higher in the North Atlantic (∼60%) than in the western North Pacific (10%–20%). This disparity between the two ocean basins exists because the majority (71%) of tropical cyclogeneses in the western North Pacific occur in the favorable synoptic environments evolved from monsoon gyres. Because the North Atlantic does not have a monsoon trough similar to the western North Pacific that stimulates monsoon gyre formation, a much larger portion of tropical cyclogeneses than in the western North Pacific are caused directly by easterly waves. This study also analyzed the percentage of easterly waves that form tropical cyclones in the western North Pacific. By carefully separating easterly waves from the lower-tropospheric disturbances generated by upper-level vortices that originate from the tropical upper-tropospheric trough (TUTT), it is observed that 25% of easterly waves form tropical cyclones in thi...