长时间强度维持台风内核区位涡的中尺度分布特征及诊断  

Diagnosis on the characteristics of the mesoscale inner-core potential vorticity in intensity-maintaining Typhoons

作　　者：李启华 陆汉城 黄小刚 钟玮 刘健文 史文丽 LI QiHua;LU HanCheng;HUANG XiaoGang;ZHONG Wei;LIU JianWen;SHI WenLi(Institutes of Aeronautical Meteorology,Air Force Academy,Beijing 100085,China;Institutes of Meteorology and Oceanography,National University of Defense and Technology,Nanjing 211101,China;Army Academy of Artillery and Air Defense,Nanjing 211100,China)

机构地区：[1]空军研究院航空气象防化研究所,北京100085 [2]国防科技大学气象海洋学院,南京211101 [3]陆军炮兵防空兵学院(南京校区),南京211100

出　　处：《地球物理学报》2019年第8期2821-2834,共14页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(41775055,41675058,41275002,41705042)资助

摘　　要：本文分析长时间强度维持“菲特”台风不同发展阶段的位涡分布特征发现:台风内核区中尺度高值PV带及其变化与台风强度变化具有伴随关系,即高值PV区与内核区强对流不仅具有对应关系;而且其生命史与台风强盛维持期一致;此外在眼墙区附近位涡梯度最大.分析还指出:垂直剖面上的高值PV呈现由单极位涡态(台风发展加强期)向中空位涡态(台风强盛维持期)的转变,到台风快速衰减期,又形成PV量值较小的单极位涡态.位涡收支方程诊断表明:内核区域水平平流、垂直输送和凝结加热的初始增强和大值收支带不仅对台风内中尺度高值位涡分布及长时间强度维持具有重要影响,而且具有伴随关系.此外,位涡收支各项对位涡态的转变起着不同的作用,其中凝结加热在台风强盛期中空位涡塔的建立中作用明显,水平平流项则在眼墙区的位涡塔中上层有着正贡献,垂直输送在高值PV分布的再分配中起中介作用.Based on the modeling dataset,the distribution of the meso-scale potential vorticity(PV)in an intensity-maintaining Typhoon Fitow(2013)at different stages is analyzed.Results show that PV distributes asymmetrically in the inner-core with peak values accompanied by the intensity changes,which features with 1)the PV peaks with the convective bursts;2)the lifetime of the brand of peak PVs is coincided with the maintenance of the peak intensity of Typhoon;3)the highest radial gradient of PV occurs near the eyewall.Vertical cross-section shows that the peak PV transfers from a monopole to a hollow pole pattern as the typhoon evolves from intensifying phase to intensity-maintaining phase,while the reduced PV during the weakening stage of Typhoon shows another monopole.The horizontal distribution of the PV shows that the highest vales locating in the lower layers with an annular shape.The PV budget equation is used to diagnose the contribution of the horizontal and vertical advection of PV and the condensation heating to the PV tendency.Results show that the horizontal and vertical advection of PV,and the condensation heating are all important to the intensity maintenance.The condensation heating plays a key role in developing the hollow pattern of PV during the intensity-maintaining stage,the horizontal advection term contributes positively to middle-to-upper-levels PV near the eyewall,and the vertical advection term dominates in redistributing the peak values of PV.

关 键 词：中尺度位涡 中空位涡和单极位涡 位涡收支 台风 

分 类 号：P444[天文地球—大气科学及气象学]