Journal of Arid Meteorology

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Analysis of Boundary Layer Easterly Wind Structure During a Returning Flow Snowing Weather Process

HUANG He1YU Lei1WANG Zhichao1MA Hongqing1WANG Yingang2   

  1. 1. Baoding Meteorological Bureau of Hebei Province,Baoding 071000,China;
    2. Zhangjiakou Meteorological Bureau of Hebei Province,Zhangjiakou 0753000,China
  • Online:2013-12-14 Published:2013-12-14

一次回流降雪过程边界层东风结构分析

黄鹤1于雷1王志超1马鸿青1王银钢2   

  1. 1. 河北省保定市气象局,河北 保定 071000;
    2. 河北省张家口市气象局,河北 张家口 0753000
  • 作者简介:黄鹤(1981 - ),男,蒙古族,工程师,主要从事天气预报工作. E - mail:hh -218415@163. com
  • 基金资助:

    气象行业专项“华北、东北暴雨发生发展特点及预报技术研究(GYHY200906011)”资助.

     

Abstract:

Based on conventional observation data and NCEP reanalysis data,a snow process caused by a return flow was analyzed,
which occurred in Hebei in the morning of December 23,2010. The results show that the northerly wind related to the Mongolia cold
high blew cold air eastwards into the northeast plain and turned southwestly into the central and south part of Hebei Province,and the
easterly wind in the boundary layer carried water vapor from the Bohai Sea into the central and south part of Hebei. It was characterized
by“the wet and cold”before snow,but dominated by“the dry and cold”during snowfall. The easterly wind climbed along the Taihang
Mountain,and related water vapor provided a favorable condition for the snowfall under the topographic forcing. Water vapor flux diver-
gence in the boundary layer was characterized by the zonal convergence,which resulted by water vapor advection before snow and dur-
ing snowfall wind field convergence was dominant.

Key words: snowfall, return flow, topography, structure

摘要:

利用常规观测资料和 NCEP 1° ×1°再分析资料,对2010 年12 月23 日凌晨至上午发生在河北的一次回流降雪过程进行了诊断分析,结果表明:地面蒙古冷高压外围的偏北风携带冷空气东移至东北平原后转向西南方向抵达河北中南部地区,边界层偏东气流将渤海水汽带向河北中南部;在降雪前期表现为“湿冷”,在降雪过程中表现为“干冷”;偏东风在太行山东麓地形作用下被迫抬升,其携带的水汽随之抬升,为降雪过程提供了弱的水汽条件;边界层内水汽通量散度主要表现为纬向水汽辐合,在降雪前主要由水汽平流引起,在降雪过程中主要由风场辐合造成。

关键词: 降雪, 回流, 地形, 结构

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