Long‐lasting convective systems in the outer region of tropical cyclones in the western North Pacific
Long‐lasting convective systems in the outer region of tropical cyclones in the western North Pacific
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DOI：
10.1029/2012gl053685
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发表时间：
2012-11
影响因子：
5.2
通讯作者：
Cheng-shang Lee;Buo‐Fu Chen;R. Elsberry
中科院分区：
文献类型：
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作者：
Cheng-shang Lee;Buo‐Fu Chen;R. Elsberry
长期持续的中尺度对流系统（MCS）可能会出现在西北太平洋热带气旋的外围区域，特别是与西南季风一起出现，例如在台湾造成严重洪水和山体滑坡的台风莫拉克。这些“外MCS”是从遥远的雨带发展而来的线性对流系统，具有巨大的冷云盾，持续时间超过6小时。这些外部MCS对台风降雨预报很重要，因为当它们与陆地和地形相互作用时，暴雨会产生严重的洪水，而这些洪水与中心附近的降雨是分开的。1999-2009年期间发生的109起外部MCS使用红外和被动微波图像进行识别。在北太平洋西部的所有台风中，约有22%在其生命周期中至少有一个外部MCS。在85%的QuikSCAT海洋10米风观测的外部MCS中，层状降水区下方中尺度地面急流左侧的正切变涡度可能有助于新对流单体的持续形成。
Long‐lasting mesoscale convective systems (MCSs) may occur in the outer region of tropical cyclones in the western North Pacific, especially in conjunction with the southwest monsoon as in the case of Typhoon Morakot that caused great flooding and landslides in Taiwan. These “outer‐MCSs” are linear convective systems that develop from distant rainbands, have a large cold cloud shield, and last more than six hours. These outer‐MCSs are important for typhoon rainfall forecasting because of the torrential rainfall when they interact with land and terrain to produce serious flooding that is separate from the rainfall near the center. A total of 109 outer‐MCSs that occurred during 1999–2009 are identified using infrared and passive microwave images. About 22% of all typhoons in the western North Pacific have at least one outer‐MCS during their life cycle. In 85% of the QuikSCAT oceanic 10‐m wind observations of outer‐MCSs, positive shear vorticity on the left side of mesoscale surface jets below the stratiform precipitation regions may be contributing to the continuous formation of new convective cells.