| The eastern Chinese seas which includes the East China Sea and the Yellow Sea is relatively narrow,with Taiwan island,Ryukyu islands and the Kuroshio. The water depth difference between northern and southern parts is nearly thousand meters,making TIOEs different from these eddies in the open sea. The asymmetric structure and associated air-sea interaction of typhoon-induced ocean eddies (TIOEs) in the eastern Chinese seas are analyzed reanalysis product and numerical simulation. In particular,the characteristics and energy transfer of the TIOEs in different regions off the Chinese coastline are investigated. The influence mechanism of environmental factors on typhoon ocean vortex is studied by regional ocean numerical simulation.We found the TIOEs can be divided into three groups by k-prototype method and path. We also divided the oceans into three zones according to water depth and the Kuroshio position. We found the TIOEs can be divided into three groups based on the tracks of typhoons that induced them: Zone I covered a wide deep water region of the southern part of the Kuroshio in the western Pacific; Zone II covered the central part of the Kuroshio; Zone ? covered the shallow water of the northern part of the Kuroshio. These eddies in Group A were the strongest and could reverse the Kuroshio at places; the eddies in Group B were weakened by Taiwan Island and the Kuroshio and their shapes were affected, too; and the eddies in Group C were affected by the coastline and island chain, they generated new vortices or enhanced the eastern part of the Kuroshio. Strong currents of the eddies in Zone I and Zone II of low latitude provided more latent heat flux , which supported typhoon development. The strong divergence areas of the eddies favored upwelling-induced cooling,low salinity. The vertical structure of typical typhoon vortices showed that the strength of the upwelling was proportional to the water depth in each zone, but weaker than coastal upwelling nearby. The eddies weakened rapidly with depth,these eddies and their strong currents could reach a vertical extent 700m much less than water depth in both Zone ? and Zone ?. In Zone ? could reach the whole layer 80m and the circulation reversed in the lower layer. Inside the eddy, the kinetic energy (larger than 0.2J) under strong eddy flow could only reach half way of the eddy's vertical extent.A numerical simulation of Group Ain the Yellow Sea of Zone ? as an example, to explore the mechanism of changing the TIOE's structure characterized by impact waves, bottom friction, terrain depth and energy. After the coupled wave module,the simulation results show that the sea surface flow field is obviously enhanced,the shape of the vortex is more complete, and the low water level is obviously reduced. The regional oceanic model simulates the coastal flow in the northern part of the Yellow Sea in the summer, which interacts with the typhoon ocean vortex and the coastal terrain to form the anticyclonic eddy associated with the typhoon ocean vortex. The energy transfer velocity of the two strong flow zones is faster than that of the central part, and the maintenance time is longer and the transmission is larger.The kinetic energy of the cyclonic eddy is mainly derived from the typhoon kinetic energy, the kinetic energy of the anticyclonic eddy mainly depends on the influence of the maximum gradient and terrain. The increase of the bottom friction is beneficial to the enhancement of the bottom cyclonic and anticyclonic eddy. In the significant divergence of the cyclonic eddy and the anticyclonic eddy,there is a significant surge in the salt element, but thermohaline rising seafloor topography caused by lifting and falling strength stronger. |
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