强台风“尤特”登陆前后移动路径和强度变化特征分析  

Analysis on track and intensity changes of STC Utor before and after its landing

作　　者：赵娴婷[1] 赵玉春[1] 崔春光[1] 汪小康[1] 柯丹[1] 

机构地区：[1]中国气象局武汉暴雨研究所暴雨监测预警湖北省重点实验室,武汉430205

出　　处：《暴雨灾害》2015年第3期197-205,共9页Torrential Rain and Disasters

基　　金：公益性行业(气象)科研专项(GYHY201106003;GYHY201206003;GYHY201306016);暴雨监测预警湖北省重点实验室暴雨研究开放基金(IHR201303)

摘　　要：利用美国NCEP/NCAR再分析资料和雷达拼图资料等对2013年8月13—19日1311号强台风"尤特"登陆前后的移动特征和结构强度变化进行了诊断,初步分析了"尤特"登陆后准静止维持的成因,主要结论如下:(1)"尤特"登陆后低压环流在华南持续较长时间,且15—17日环流中心稳定少动。(2)副高在"尤特"北侧形成高压坝,并从"尤特"东侧向低纬扩展,"尤特"被高压环流包围可能是其稳定少动的原因之一;此阶段环境引导气流明显减弱,也使"尤特"移动缓慢。(3)环境垂直风切变在登陆后迅速变小,对"尤特"低压环流的维持有积极作用。(4)"尤特"登陆后仍与水汽通道紧密相连,充沛的水汽利于环流中对流系统的发生发展。水汽通量和水汽通量辐合中心的分布,影响"尤特"环流中对流的分布。(5)在准静止维持阶段,涡动动能的增加利于"尤特"环流的维持,其增加主要是由于动能制造项的增强,并且高层水平通量辐合作用的增强以及区域平均动能向涡动动能的转化也都为其提供动能。Based on data from NCEP reanalysis and regional radars, the moving characteristics and structural and intensity changes of land- fall STC Utor from 13 to 19 August in 2013 were diagnosed. Meanwhile, the reasons for Utor＇ s sustaining in quasi-stationary after landfall was analyzed. It was found that the low-pressure circulation of Utor after landfall maintained quite a long time in Southern China, while the center of circulation was stable from 15 to 17 August. The subtropical high was strong and the high pressure barrier was on the north of Utor. The subtropical high also expanded into the low latitudes. Utor was surrounded by the high-pressure circulation, which may be one reason to cause Utor being stable. In this period, the weakening of environmental steering flow also caused the speed of Utor being reduced. The rapid weakening of vertical wind shear was in favor of sustaining low circulation. Utor was connected closely to a vapor channel after landfall and the sufficient moisture was favorable for the development of convection. The distribution of moisture flux and moisture convergence centers af- fected the distribution of convection. During the quasi-stationary sustaining period, the increase of eddy kinetic energy was positive to the maintenance of circulation, which was mainly due to the enhancement of kinetic energy generation term. Moreover, the upper-level horizontal convergence of eddy kinetic energy flux and the conversion from environmental kinetic energy also provided kinetic energy.

关 键 词：强台风“尤特” 准静止维持 引导气流 动能收支 

分 类 号：P457.8[天文地球—大气科学及气象学]