LAUSR

The asymmetrical structure of typhoon-induced ocean eddies (TIOEs) in the East China Sea (including the Yellow Sea) and the accompanying air–sea interaction are studied using reanalysis products. Thirteen TIOEs are analyzed and divided into three groups with the k-prototype method: Group A with typhoons passing through the central Yellow Sea; Group B with typhoons re-entering the sea from the western Yellow Sea after landing on continental China; and Group C with typhoons occurring across the eastern Yellow Sea near to the Korean Peninsula. The study region is divided into three zones (Zones I, II and III) according to water depth and the Kuroshio position. The TIOEs in Group A are the strongest and could reverse part of the Kuroshio stream, while TIOEs in the other two groups are easily deformed by topography. The strong currents of the TIOEs impact on the latent heat flux distribution and upward transport, which facilitates the typhoon development. The strong divergence within the TIOEs favors an upwelling-induced cooling. A typical TIOE analysis shows that the intensity of the upwelling of TIOEs is proportional to the water depth, but its magnitude is weaker than the upwelling induced by the topography. In Zones I and II, the vertical dimensions of TIOEs and their strong currents are much less than the water depths. In shallow water Zone III, a reversed circulation appears in the lower layer. The strong currents can lead to a greater, faster, and deeper energy transfer downwards than at the center of TIOEs.摘要运用再分析资料对2005-2015年间发生在东中国海上由台风引致的海洋涡旋(TIOEs)及其伴随的海气相互作用进行了深入分析. TIOEs是一种具有非对称结构的海上中尺度涡旋, 采用k氏样本分类方法将13个影响东中国海的台风及其引致的海洋涡旋依据路径分为A, B, C三类. A类台风路径沿黄海中线北上, B类台风自登陆中国后从黄海西岸再次入海, C类台风路径偏黄海东部, 接近朝鲜半岛. 进一步地依据东中国海的水深和黑潮的位置, 研究区域也被分成三个: I, II, III. I区为黑潮以南的东海深水海域, II区为黑潮以北, 黄海以南的海域, III区为水深较浅的黄海海域. 在各组TIOEs中, A组的TIOEs最强, 能够部分地反转黑潮海流. 而另两组的TIOEs则很容易受沿海地形影响而变形. TIOEs的强海流部分影响着海气界面的潜热通量分布和向上传输, 进而影响台风的发展. 在TIOEs中的强辐散区有利于其下方的上升流和冷海温的增强及上传. 对一个典型的TIOE分析显示, TIOE中上升流的强度正比于海域的水深, 但是强度量值弱于由地形强迫的上升流. 在I区和II区, TIOE自身和其强流区的垂直尺度是显著地小于海域水深, 而在浅水III区的底层会出现一个反向环流. 与TIOE的中心区域相比较, 其强流区能够导致更强更快更深的能量向下传输.