Journal of Arid Meteorology

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Characteristics of Tropopause Evolution and Dust Vertical Transportation During a Mongolia Cyclone Dust Storm Process

JIANG Xuegong1, LI Xiazi2, WANG Dejun3   

  1. (1. Inner Mongolia Autonomous Regional Meteorological Observatory, Hohhot 010051, China;
    2. Meteorological Research Institute of Inner Mongolia Autonomous Region, Hohhot 010051, China;
    3. Meteorological Information Center of Inner Mongolia Autonomous Region, Hohhot  010051, China)
  • Online:2018-03-05 Published:2018-03-05

一次典型蒙古气旋沙尘暴的对流层顶演变及沙尘垂直输送特征

姜学恭1李夏子2王德军3   

  1. (1.内蒙古自治区气象台,内蒙古呼和浩特010051;2.内蒙古自治区气象科学研究所,内蒙古呼和浩特010051; 3.内蒙古自治区气象信息中心,内蒙古呼和浩特010051)
  • 通讯作者: 李夏子(1985—),女 博士,高级工程师,主要从事气象学和生态环境研究. E-mail:lizj_qxj@163.com。
  • 作者简介:姜学恭(1969—),男,正研级高工,主要从事天气学研究和沙尘暴研究. E-mail:jiangxuegong@aliyun.com。
  • 基金资助:

    国家自然科学基金(41365003)资助

Abstract:

The characteristics of the tropopause evolution and dust vertical transportation during a Mongolia cyclone dust storm process were studied based on the numerical simulation output. The results show that the baroclinic instability in the middle and low troposphere was primary force causing the Mongolia cyclongenesis, and downward transportation of potential vorticity in the upper level also contributed some influence to the cyclongenesis. At developing period of the cyclone, the tropopause fold performed as the funnel-shaped. Following maturation of the cyclone and formation of upper level cut low vortex, the tropopause fold performed as the double funnel-shaped, and they situated at the south side of the low vortex with one at the middle part of the trough line and the other nearby the center of the low vortex center. With weakening of the cyclone the area of the tropopause fold tended to coincide with the low vortex. The upper level jet stream located nearby the south branch of the funnel-shaped tropopause, the jet stream core stretched vertically with the strengthening of the tropopause fold, on the contrary it tended to be horizontal. At the developing period of the cyclone, the troposphere-stratosphere transportation (TST) streams located at the east and north sides of the funnel. It also was the warm sector ascending stream of the cyclone. Following maturation of the cyclone, all of the vertical ascending air streams were nearby the low vortex center, the southern ascending air stream at the east of the low vortex center and the strong ascending air stream at the front of the trough brought significant TST. When the cyclone weakened the TST brought by the southern and vertically ascending air streams decreased obviously. But the eastern air stream at the northeast quadrant of the low vortex brought irreversible TST.

Key words: dust storm, tropopause fold, troposphere-stratosphere transportation, three- dimensional structure

摘要:

利用高分辨率中尺度数值模拟结果,对一次蒙古气旋沙尘暴过程的对流层顶折叠和沙尘对流层-平流层输送特征进行分析研究。结果发现:本次过程蒙古气旋的发展由对流层中低层斜压强迫引发,对流层中高层高空位涡下传是蒙古气旋发展的另一影响因素。蒙古气旋发展阶段,对流层中高层为低压槽,对流层顶折叠呈漏斗状;随着蒙古气旋的成熟及高空切断低涡的形成,对流层顶折叠变为双漏斗状,位置偏于低涡区南侧,分别位于低槽槽线中段和低涡中心附近。之后的气旋减弱阶段,对流层顶折叠逐渐与低涡区趋于重合。高空急流位于漏斗状对流层顶折叠区南支附近,当对流层顶折叠加强时,高空急流核向下拉伸,反之,高空急流核则趋于水平。对流层顶折叠呈漏斗状的气旋发展阶段,对流层-平流层输送气流位于漏斗东侧、北侧,即气旋暖区螺旋上升气流,位置越偏东、偏北,输送气流的强度和范围越大;气旋成熟阶段,对流层顶折叠呈双漏斗状(经向)和平直带状(纬向),低涡中心附近的准垂直上升气流、低涡中心以东的低涡区偏南上升气流、以及低涡前部槽前强上升气流均产生明显的对流层-平流层输送。气旋减弱阶段,偏南上升气流、准垂直上升气流导致的对流层-平流层输送明显减弱,低涡东北象限偏东气流则能够形成不可逆的对流层-平流层输送。

关键词: 沙尘暴, 对流层顶折叠, 对流层-平流层输送, 三维结构

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