| 摘要: |
| 1311号台风“尤特”在广东登陆后，由前期较稳定的西北方向移动转向偏北方向移动，而后又掉头转向西南方向移动.采用NCEP和 Micaps 提供的常规资料对台风“尤特”登陆后曲折路径特征、环境流场变化、引导气流方向和大小的改变及台风“尤特”不对称结构的演变特征等进行分析，寻我台风“尤特”登陆后路径突变和预报误差产生的原因.结果显示：欧亚中高纬多波动的环境流场导致引导气流多变是台风“尤特”后期移动路径复杂的主要原因；赤道高压北抬及北方冷空气南下也起到重要作用，台风“尤特”先后受东南、偏南及东北气流引导，路径发生突变.台风“尤特”移向、移速与500 hPa地转引导气流方向及大小密切相关，且引导气流改变早于台风路径的改变.与其移动路径的3个不同阶段对应，台风“尤特”结构经历了从 NE—SW到SE—NW,再到NW—SE与NE—SW共存，但NW—SE 更明显的不对称结构变化过程，并对其移向产生了影响.在应用数值预报产品做台风路径预报时，要结合引导气流和台风不对称结构的变化进行修正。 |
| 关键词: 海洋气象学；台风“尤特” 曲折路径；环境场；地转引导气流；不对称结构 |
| DOI： |
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| 基金项目:中国气象局2014年预报员专项资助项目(CMAYBY2014-052) |
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| Analysis of anomaly movement of typhoon Utor |
| LI Huijin,HUANG Mingce,QIN ChangHliu |
| (Iaibin Municipal Burean of Meteomology,Iaibin 546100,China;Guangi Meteorolbgical Observatoy,Nanning 530022,China) |
| Abstract: |
| Theunusual path andtheasymmetric structureof typhoon Utor in its anomaly movement and thevanationofciculatiom and steering flowwere studied.The reasons of its suddenly changed path and the forecast eror werefound.The results showed that,the sudden change of ciculation was the most important reason of typhoon Utorscomplicated path in thefinal phase of its life.After typhoon Utor moved into the South ChinaSea,a strong and sta-ble squareshaped subtopical high was located on the west Pacific,and then weakened and moved northward fol-lowing a temporary westwand strengthening,and the continental cold high moved southward at last.typhoon Utorwas dominated in turn by southeasterly,thensoutherly,at last northeasterly steering flow,corresponding to the var-iation ofcirculation.The path of typhoon Utor was closely related to the direction and strength of the geostrophicstering flow on 500 hPa.The change of steering flow happened before the change of path.When thedirection ofsteering flow changed,thedirection of path changed.When thesteeringflow weakened,the velocity of typhoonUtor reduced.Coresponding to 3 diferent stages of changing path,typhoon Utor's asymmetric structure wentthrough 3 stages.The NE—SW stage(the stream was intensive at the northeast side and sparse at the southwestside),then the SE—NW stage,at last thestage that NW—SE was much significant,coexisting with NE—SW.The asymmetrie structure also impacted on the path.The path prediction madeby numericalmodels should be cor-rected acconding to the changes ofthe subtropical high and typhoon's asymmetry structure. |
| Key words: marine meteomology typhoon Utor unusual path circulation geostrophic steering flow asymmetricstructure |
