相似路径台风“杰拉华”和“海葵”降水差异成因分析

利用常规资料、卫星云图和NCEP 1°×1°再分析资料,对"杰拉华"(2000)和"海葵"(2012)两个路径相似但造成的降水有明显差异的台风进行对比分析。结果表明,登陆后台风环流维持的时间和强度是造成两次不同降水的主要原因,台风登陆后减弱快,维持时间短,则降水弱;反之,则降水强。台风登陆前及登陆时相对副热带高压位置是否孤立等环流背景决定了台风维持时间及降水强度。台风与海上季风气流连接,低层环流强使其南侧偏南气流强盛,移速慢、上升运动强均对降水有重要贡献。台风降水与海上水汽通道是否阻断有重要关系,且与其南边界、西边界水汽输入有很好的对应关系,北边界水汽对于降水影响不大。

Analysis of the Cause of Precipitation Difference Induced by the Typhoons “Jelawat” and “Haiku” with Similar Tracks

The conventional data, satellite cloud image and NECP（1°×1°） reanalysis data were employed to analyze the cause of precipitation difference induced by the Typhoon Jelawat（0008） and Typhoon Haikui（1211） with similar tracks. The result showed that the difference intensity of precipitation was caused mainly by the maintenance time and intensity of the typhoon circulations.Short maintenance time and weak intensity after landing led to less precipitation, and vice versa. The maintenance time of typhoon and precipitation intensity were affected by its circulation and the position of subtropical high before and after landing. The typhoon was connected with the maritime monsoon airflow, strong ascending motion and slow-moving speed caused by the strong low-level circulation, which had an important impact on typhoon rainfall. Also, the rainfall had an important relationship with the blocking of water vapor channel. Water vapor inflow from the south and west border was corresponding to the precipitation of typhoon.