台风“芭玛”在北部湾迅速加强的特征分析

Rapid Strengthening of Typhoon“Parma”in Beibu Gulf

为了找出台风在北部湾迅速加强环境场的主要影响因子,以积累此类台风预报经验,利用NCEP再分析资料、NOAA日平均海表温度等资料,对台风"芭玛"在北部湾迅速加强过程的环境因子进行研究。结果表明:(1)台风"芭玛"迅速加强的形势场背景为阻塞高压崩溃南压,横槽转竖,南亚高压稳定少动,副热带高压减弱且北侧高压坝崩溃,地面为冷高压;(2)环境风场垂直切变由强切变转为弱切变,最强负垂直螺旋度从中高层开始下沉并调整强度,低层环境大气辐合增强及高层的辐散稳定维持,环境大气不稳定性增强,台风西侧有弱冷空气嵌入,增强的水汽输送以及北部湾海面大于27.5℃的SST,这些是台风快速加强的重要因子。

The paper aims to find out the major influencing factors of environmental field, which cause a rapidstrengthening of typhoon in Beibu gulf, thus to accumulate forecast experience for such type of typhoon. Theenvironmental factors of typhoon＂Parma＂rapid strengthening process in Beibu gulf were studied by usingNCEP reanalysis data and NOAA daily average sea surface temperature data. The results showed that：（1） thestrengthening was caused by blocking highs collapsing and moving to south, the transversal trough changing tovertical one, with stable south Asia high, weakened subtropical high and collapsed north side high dam, andcold ground high;（2） the important factors which led to rapid strengthening of typhoon were vertical shear ofenvironmental wind field changing from the strong shear to weak shear, the strongest negative vertical spiraldegrees sinking from the middle- high level and adjusting its intensity, the strengthening of the low- levelenvironmental atmospheric convergence and the maintaining of the high-level divergence, the enhancing of theenvironmental atmospheric instability, the embedding of weak cold air on the west side of typhoon, enhancedwater vapor transport and the SST of Beibu gulf over 27.5℃.