入侵冷空气强度对台风变性过程的影响

Impacts of the intrusion intensity of cold air on extratropical transition of typhoon Krosa

利用WRF中尺度模式对0716号"罗莎"台风的变性过程进行数值试验研究,讨论不同强度的入侵冷空气对台风变性过程的影响,结果表明适当强度冷空气入侵有利于斜压能的积累和释放,是导致台风变性的重要因素,而太强或太弱的冷空气都不利于台风的变性加强。当冷空气减弱时,台风登陆后边界层的热量通量减少,在没有新的能量供给的情况下,台风由于边界层摩擦作用和水汽供应不足而逐渐消散;当入侵冷空气过强时,台风内部会被迅速填塞,暖心变为冷心,从而逐渐消散。

The Penn State NCAR nonhydrostatic mesoscale model （WRF） is used to simulate the process of extratropical transition of typhoon Krosa with different intrusion intensity of cold air. The re- suits show that suitable intrusion intensity of cold air is of benefit to accumulating and releasing the ba- roclinic energy and plays an important role in extratropical transition of typhoon, but too weak or too strong cold air is not conducive to extratropical transition of typhoon neither. When the intensity of cold air is too weak, heat flux is reducing after the landfall, typhoon will disappear by the influence of friction and the reduction of water vapor flux. When the intensity of cold air is too strong, typhoon warm core will be quickly transformed to cold core by strong intensity of cold air, typhoon will quickly disappear.