本文利用日本气象厅的台风最佳路径数据和美国国家环境预报中心1°×1°逐6h再分析资料,对2010年第13号台风“鲇鱼”的发生发展过程进行详细的分析,发现该过程中主要的影响天气系统有副热带高压和中纬度西风槽等,然后利用分部位涡反演的方法,进一步研究各系统对“鲇鱼”路径与强度变化的影响.得到结果如下:(1)路径方面:台风“鲇鱼”发展过程中,前期主要受副高环流影响向西北方向运动;中期主要是受到位于华南的高压单体的东北风引导气流影响向南转折;后期由于西风槽增强南压,台风与西风槽底接近,“鲇鱼”受到西风槽系统产生的西南风引导气流的作用,向东北偏折.(2)强度方面:在台风强度达到最大时,西风槽、副高、台风等系统位涡扰动对应的水平风垂直切变为最小,不会抑制台风加强;后期西风槽和副高扰动产生的风垂直切变逐渐减小,但随着“鲇鱼”逐渐接近陆地,环境风切增大,台风强度逐渐减弱.这些结果表明,在副高强度大并且与台风距离近时,“鲇鱼”运动主要受副高环流的引导.而随着“鲇鱼”不断西移北抬,副高远离台风其影响几乎消失,中纬度西风槽成为影响台风运动的主要系统.
Based on the reanalysis data from the National Centers for Environmental Prediction and best track data from Japan Meteorological Agency, the development of super typhoon MEGI(2010)over the Northwest Pacific is analyzed in this work. The results show that the westerly trough and the subtropical high are the main impacts. Then the piecewise potential vorticity(PV)inversion is used to separate the disturbance PV of westerly trough(TR), tropical cyclone (TC), subtropical high(SH), and others (RP). The results are : ( 1 ) Path of MEGI .. At the early stage, SH,as a major factor, guided MEGI to move wesl,ward. In the middle of the process, South High caused the southward deflection of MEGI's path. In the latter part o{ the whole process, the disturbance PV of TR lead to MEGI's turning eastward. (2)Strength of MEGI:When MEGI reached its maximum intensity, the horizontal wind vertical shear of TC,TR,SH and RP were all very small. At last,MEGI weakened while it got close to the land,as aresult of the increasing horizontal wind vertical shear. All of these indicate that,when the SH is strong and close to the tropical cyclone,the movement of MEGI is guided by SH. While the SH is weak, and TR is strong, MEGI is guided by TR.