Remote Thermodynamic Impact of the Kuroshio Current on a Developing Tropical Cyclone Over the Western North Pacific in Boreal Fall
Remote Thermodynamic Impact of the Kuroshio Current on a Developing Tropical Cyclone Over the Western North Pacific in Boreal Fall
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DOI：
10.1029/2019jd031356
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发表时间：
2020-01
期刊：
影响因子：
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通讯作者：
Keita Fujiwara;R. Kawamura;T. Kawano
中科院分区：
文献类型：
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作者：
Keita Fujiwara;R. Kawamura;T. Kawano
为了研究热带气旋(TC)发展和从黑潮流向TC的水汽输送之间的远程联系，我们进行了修改黑潮表面潜热通量(LHF)的敏感性试验，将云分辨区域模式和拉格朗日诊断应用于2010年10月逼近日本的台风Chaba。天气环境的特征是日本周围的大陆起源的反气旋和北移的TC的结合，通过增强的经向气压梯度在黑潮上产生了低层东北风。当在这种环境气流下人为地减少或移除黑潮上的LHF时，热带气旋的强度在其发展阶段明显地减弱，这意味着由于环境气流而导致的水汽流入在热带气旋发展中的重要性。在敏感性试验中，由于中纬度来源的干空气能从黑潮中获得少量的水汽补给，入流层内的等效位温值趋于减小，从而有利于TC眼壁周围对流上升气流和下降气流的减弱。提示这种变化可能是TC发生的抑制因素。如果满足有利的天气条件，黑潮有可能对西北太平洋的热带气旋强度产生远程影响。
To examine the remote linkage between tropical cyclone (TC) development and moisture transport from the Kuroshio Current toward the TC, we conducted sensitivity experiments that modified the surface latent heat flux (LHF) over the Kuroshio, applying a cloud‐resolving regional model and Lagrangian diagnostics to Typhoon Chaba as it approached Japan in October 2010. The synoptic environment was characterized by a combination of an anticyclone of continental origin around Japan and the northward‐migrating TC, bringing about low‐level northeasterlies over the Kuroshio through an enhanced meridional pressure gradient. When the LHF over the Kuroshio was artificially reduced or removed under this environmental flow, the intensity of the TC, which was fully away from the domain in which the LHF is modified, appreciably attenuated during its developing stage, implying the importance of moisture influx due to the environmental flow in TC development. Since dry air of midlatitude origin could receive little of the moisture supply from the Kuroshio in the sensitivity experiments, the values of equivalent potential temperature within the inflow layer tend to decrease, thus facilitating the weakening of convective updrafts and downdrafts around the eyewall of the TC. It is suggested that such changes act as an inhibitory factor for TC development. The Kuroshio has the potential to remotely influence the TC intensity over the western North Pacific if favorable synoptic conditions are satisfied.