段旭, 张瑾文. 孟加拉湾东北路径登陆风暴结构特征[J]. 云南大学学报(自然科学版), 2014, 36(5): 691-703. doi: 10.7540/j.ynu.20130028
引用本文: 段旭, 张瑾文. 孟加拉湾东北路径登陆风暴结构特征[J]. 云南大学学报(自然科学版), 2014, 36(5): 691-703. doi: 10.7540/j.ynu.20130028
DUAN Xu, ZHANG Jin-wen. The structure characteristics of landing storms in the northeast path over bay of Bengal[J]. Journal of Yunnan University: Natural Sciences Edition, 2014, 36(5): 691-703. DOI: 10.7540/j.ynu.20130028
Citation: DUAN Xu, ZHANG Jin-wen. The structure characteristics of landing storms in the northeast path over bay of Bengal[J]. Journal of Yunnan University: Natural Sciences Edition, 2014, 36(5): 691-703. DOI: 10.7540/j.ynu.20130028

孟加拉湾东北路径登陆风暴结构特征

The structure characteristics of landing storms in the northeast path over bay of Bengal

  • 摘要: 利用NCEP/NCAR(11)再分析资料,对20012010年孟加拉湾东北路径登陆风暴进行合成分析,研究了风暴登陆前后水平流场、垂直环流、涡度、散度和垂直风切变等大气要素场,得到了其结构特征:①风暴中心气流一致性气旋性流入仅限于900 hPa层以下,环形复合带的厚度随风暴登陆时的减弱而减小;②风暴的垂直环流不对称,中心周围上升气流垂直、风速较大,风暴西侧气流向外流出层较高、东侧气流向外流出层较低,南侧和北侧气流几乎向北倾斜;③风暴涡旋结构基本对称,整个对流层内涡旋柱比较垂直,登陆前后圆形涡旋形态逐渐向椭圆形形态变化;④登陆前风暴中心周围对流层底层辐合、高层辐散结构比较脆弱,登陆时,对流层中高层风暴两侧变为了气流辐合辐散不对称结构;⑤孟加拉湾风暴生存环境为垂直风切变较小、梯度变化较大的区域内,风暴向垂直风切变最大梯度方向移动.

     

    Abstract: Based on NCEP/NCAR (11) reanalysis data,the pattern of the landing storms of the bay of Bengal in northeast path by comparative and composite analysis from 2001 to 2010 has been analyzed.The results show that the consistency cyclonic inflow layer of storm center is limited to 900 hPa below.The thickness of the annular complex zone reduces with storms landfall.The vertical circulation of storms shows asymmetry,and the layer of air outflow in west of storms is higher but the layer of it in east is lower.The south and north of storms is northward,and the vertical updraft speed in central and peripheral of them is greater than that of other areas.The vortex structure of storms is basic symmetry and the vortex column in entire troposphere is vertical.The vortex feature of storms changes from circularto ovalfrom landing prior to landing.Before landing,the structure of convergence at the bottom layer and divergence at the high level in the troposphere over the center of storms around is weak.The structure of convergence and divergence at middle-high level of troposphere along both sides of storms is asymmetric.Bengal storms survival environment presents smaller vertical wind shear,larger gradient changes regional,and storms move along maximum vertical wind shear gradient direction.

     

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