img

官方微信

高级检索

中国沙漠 ›› 2021, Vol. 41 ›› Issue (5): 219-228.DOI: 10.7522/j.issn.1000-694X.2021.00094

• • 上一篇    下一篇

河西走廊不同强度冷锋型沙尘暴环流和动力特征

李玲萍1,2(), 李岩瑛1,2, 李晓京2, 王博3, 胡丽莉2   

  1. 1.中国气象局兰州干旱气象研究所 甘肃省干旱气候变化与减灾重点实验室/中国气象局干旱气候变化与减灾重点开放实验室,甘肃 兰州 730020
    2.武威市气象局,甘肃 武威 733000
    3.古浪县气象局,甘肃 古浪 733100
  • 收稿日期:2021-03-15 修回日期:2021-08-04 出版日期:2021-09-20 发布日期:2021-09-23
  • 作者简介:李玲萍(1977—),女,甘肃定西人,理学硕士,高级工程师,主要从事短期预报及沙尘暴、暴雨等灾害性天气研究。E-mail: wwqxjllp@163.com
  • 基金资助:
    国家自然科学基金面上项目(41975015);武威市市列科技计划项目(WW190102)

Characteristics of circulation and dynamic of the different cold front sandstorm processes in Hexi Corridor

Lingping Li1,2(), Yanying Li1,2, Xiaojing Li2, Bo Wang3, Lili Hu2   

  1. 1.Key Laboratory of Arid Climatic Change and Reducing Disaster of Gansu Province / Key Open Laboratory of Arid Change and Disaster Reduction of CMA,Institute of Arid Meteorology,China Meteorological Administration,Lanzhou 730020,China
    2.Wuwei Meteorological Bureau,Wuwei 733000,Gansu,China
    3.Gulang Meteorological Bureau,Gulang 733100,Gansu,China
  • Received:2021-03-15 Revised:2021-08-04 Online:2021-09-20 Published:2021-09-23

摘要:

利用常规气象观测资料、ECMWF ERA-Interim 逐6 h的0.75°×0.75°再分析资料,对河西走廊3次不同强度区域性典型冷锋型沙尘暴的大气环流形势和高低层水平螺旋度、uv分量场和垂直速度进行对比分析。结果表明:(1)影响沙尘暴强度和范围的主要因素有高空冷空气强度、高低空风速、地面热低压中心、冷锋前后变压梯度以及冷锋入侵河西走廊的时间;(2)700 hPa风速和冷锋入侵河西走廊的时间影响最明显,低空风速越大,沙尘暴往往越强,强沙尘暴一般出现在中午到傍晚。一般、强和特强沙尘暴700 hPa风速阈值分别为18、22 m·s-1和24 m·s-1;(3)高(低)层正(负)水平螺旋大值中心越大,配合越好,下游沙尘暴强度越强,一般、强和特强沙尘暴的高(低)层水平螺旋度正(负)值中心阈值分别为400(-200)m2·s-2、800(-1 000)m2·s-2和1 000(-1 000)m2·s-2;(4)高空强风动量下传到近地面的风速越大,沙尘暴强度越强,一般、强和特强沙尘暴下传到近地面的uv分量风速阈值分别为8、10 m·s-1和12 m·s-1;(5)700 hPa以下上升运动越强,沙尘暴强度越强,一般、强和特强沙尘暴700 hPa以下垂直速度中心阈值分别为-0.4、-0.7 Pa·s-1和-1.40 Pa·s-1;(6)垂直风场表现为≥15 m·s-1大风下传高度越低,沙尘暴强度越强,一般、强和特强沙尘暴下传高度分别为600、500 m和50 m以下。

关键词: 沙尘暴, 大尺度环流, 高低层水平螺旋度, uv分量场, 垂直速度

Abstract:

Based on convention observation meteorological data and the ECMWF ERA-Interim 6 hourly reanalysis data with resolution 0.75°×0.75°,the atmospheric circulation, horizontal helicity, uv component field and vertical velocity of three typical regional cold front sandstorms on March 28-29,2010, April 10-11,2006 and April 24,2010 in Hexi Corridor were analyzed. The results showed that:(1)The main factors affecting intensity and range of sandstorms were high altitude cold air intensity, high and low wind speeds, ground low pressure center, variable pressure gradient before and after the cold front and the time of cold front invading Hexi Corridor. (2)The most obvious factors affecting intensity of sandstorm were 700 hPa wind speed and time of cold front invading Hexi Corridor. The greater low wind speed was, the stronger sandstorm was. Strong sandstorm usually occurred from noon to evening. 700 hPa wind speed threshold of general, strong and very strong sandstorms were 18 m·s-1, 22m·s-1 and 24 m·s-1, respectively. (3)The bigger positive (negative) values of high (low) horizontal helicity and the better their coordination from high to low were, the stronger of sandstorm in the downstream was. High and low-level helicity positive (negative) center value threshold of general, strong and very strong sandstorms were 400(-200)m2·s-2, 800(-1 000)m2·s-2 and 1 000(-1 000)m2·s-2. (4)The uv component field showed that the greater of wind speed down to near the ground was, the stronger the intensity of standstorm was. The uv component wind speeds threshold of general, strong and very strong sandstorms were 8 m·s-1, 10 m·s-1 and 12 m·s-1. (5)The stronger rising movement below 700 hPa was, the stronger of sandstorm was. The vertical speed center threshold below 700 hPa of general, strong and very strong sandstorms were -0.4 Pa·s-1, -0.7 Pa·s-1and -1.4 Pa·s-1,respectively. (6)The vertical wind field shows that the lower the descending height of ≥15 m·s-1strong wind was, the stronger the intensity of standstorm was. The downwind altitude of the general, strong and very strong sandstorms were 600 m, 500 m and 50 m, respectively.

Key words: sandstorm, atmospheric circulation, horizontal helicity, uv component field, vertical velocity

中图分类号: