主办单位:中国气象局沈阳大气环境研究所
国际刊号:ISSN 1673-503X
国内刊号:CN 21-1531/P

气象与环境学报 ›› 2022, Vol. 38 ›› Issue (6): 1-9.doi: 10.3969/j.issn.1673-503X.2022.06.001

• 论文 • 上一篇    下一篇

基于四维变分同化的“6·23”阜宁龙卷大涡模拟研究

刘达之1(),姚聃1,2,*(),梁旭东1   

  1. 1. 中国气象科学研究院灾害天气国家重点实验室, 北京 100081
    2. 中国气象局气象探测中心, 北京 100081
  • 收稿日期:2021-05-24 出版日期:2022-12-28 发布日期:2022-12-27
  • 通讯作者: 姚聃 E-mail:liudazz@foxmail.com;yaod@cma.gov.cn
  • 作者简介:刘达之, 女, 1996年生, 在读硕士研究生, 主要从事中小尺度数值模拟研究, E-mail: liudazz@foxmail.com
  • 基金资助:
    国家重点研发计划(2018YFC1506103);国家自然科学基金青年基金(41705028)

Large-eddy simulations of the tornado over Funing on June 23 using a four-dimension variational data assimilation

Da-zhi LIU1(),Dan YAO1,2,*(),Xu-dong LIANG1   

  1. 1. State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China
    2. Meteorological Observation Center, China Meteorological Administration, Beijing 100081, China
  • Received:2021-05-24 Online:2022-12-28 Published:2022-12-27
  • Contact: Dan YAO E-mail:liudazz@foxmail.com;yaod@cma.gov.cn

摘要:

应用WRF模式和四维变分同化方案(4DVar), 进行2016年6月23日江苏省盐城市阜宁县EF4级超强龙卷大涡模拟研究。结果表明: NCEP/GFS预报场同化高频次地面观测和雷达风场资料能有效改进模式初始场, 在阜宁附近模拟生成对流单体。在此基础上使用约100m水平分辨率的大涡模拟, 可以清晰模拟出超级单体的钩状回波和类龙卷涡旋结构。进一步分析模拟结果发现, 对流有效位能和垂直风切变在天气尺度范围内均能达到有利于超级单体发生的阈值。有利于生成龙卷的高风暴相对螺旋度(SRH)集中在龙卷超级单体发生区域的风暴尺度范围内, 且具有较好的指示性。尽管SRH的强度随模式分辨率有所提高, 但其空间分布并无明显变化, 在3km水平分辨率网格已出现明显信号。

关键词: 类龙卷涡旋, 风暴相对螺旋度, 上升气流螺旋度

Abstract:

A simulation is produced for the June 23, 2016 Funing (in Yancheng city, Jiangsu province) via WRF model and four-dimensional data variational assimilation.Results show that the first guess can be improved by assimilation of high-resolution surface and radar wind field observations from NCEP/GFS data, while convection cells are generated near Funing.Based on this, the simulation successfully produces hook echo and the tornado-like vortex structure when the large-eddy simulation is conducted on the 100-m grid.Furthermore, both convective available potential energy and vertical wind shear can reach the threshold value favorable for the occurrence of supercell in the synoptic scale.The high storm relative helicity (SRH) exhibits in the realm of parent supercell within a storm scale range, which is an indication of tornadogenesis.Although the intensity of SRH varies with resolution, its spatial distribution has not changed significantly, and signals are manifest using a horizontal grid spacing of 3 km.

Key words: Tornado-like vortex, Storm relative helicity, Updraft helicity

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