8712号台风和9909号热带风暴引发的温州秋后台风倒槽特大暴雨对比分析

Comparison of Wenzhou abnormal heavy rains associated with Typhoon 8712 and Tropic Cyclone 9909

文中主要以8712号台风和9909号热带风暴为个例,运用MM5中尺度模式结合Q矢量等物理量计算NCEP资料,通过模拟、统计、分析研究,讨论浙东南温州沿海秋后台风倒槽强降雨特征.结果表明秋季在厦门以南至广东东部登陆的台风,在浙东南温州沿海形成台风倒槽.该倒槽内暖湿切变线的中尺度对流复合体(MCC)是引起特大暴雨的重要条件;其次,中高层弱干冷空气进入台风倒槽上空和低层强的暖湿平流相结合,使得不稳定能量释放是产生特大暴雨的另一种重要原因之一.

Using MM5 numerical model and NCEP data,the Wenzhou abnormal heavy rain associated with Typhoon 8712 and Tropic Cyclone 9909 were studied. The results show that the autumn tropic cyclone landing at the east of Guangdong Province often accompanies with an inverted trough extending to the mid-south Zhejiang coast. At the special place, MCC occurred and formed important conditions for the abnormal heavy rain. On the other hand, with westerlies system interaction, such abnormal heavy rain can also be caused. The abnormal heavy rain usually located at the intersection of the southeast low level jet, in the right side of the upper level jet entrance and the weak cold air of westerlies.