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
Journal of Meteorology and Environment

Journal of Meteorology and Environment ›› 2019, Vol. 35 ›› Issue (6): 14-20.doi: 10.3969/j.issn.1673-503X.2019.06.003

• ARTICLES • Previous Articles    

Impact of terrain on an extreme snowstorm event in southeastern He'nan province

GU Xiu-jie1,2, SU Ai-fang1,2, ZHANG Ning1,2, LI Han1,2, WANG You-he1,2   

  1. 1. He'nan Key Laboratory of Agrometeorological Support and Applied Technique, China Meteorological Administration, Zhengzhou 450003, China;
    2. He'nan Meteorological Observatory, Zhengzhou 450003, China
  • Received:2018-09-22 Revised:2019-01-10 Published:2019-12-25

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Abstract: In order to fully understand the development mechanism of extreme snowstorm events in southeastern He'nan province,we analyzed the circulation background,the configuration of high-and low-level jets,and water vapor transport during an extreme snowstorm event in southeastern He'nan province from January 3 to 4,2018,using conventional sounding and ground observation data and National Centers for Environment Prediction (NCEP) 1°×1° reanalysis data.The results showed that the most fundamental synoptic-scale conditions for this event include low trough athigh levels,jets at low and middle levels,shear lines,as well as the southward motion of strong cold air.The southeastern part of He'nan province is located in a strong uplifting area due to the coupling effect of the high- and low-level jets.The southwesterly jets not only continuously provides plenty of water vapor to the snowstorm area,but also contributes to the dynamic lifting and unstable energy release,which favors the development and maintenance of the snowstorm event.The southeastern part of He'nan province is located on the northeastern side of the Dabie Mountains and Tongbai Mountains;the surrounding terrain topography is quite complicated.In order to explore the influence of topography on this extreme snowstorm event,we attempt to simulate the impact of southeastern terrain on precipitation using the Weather Research and Forecast (WRF) model. The comparison between control experiment and sensitivity experiment shows that the precipitation increases by 4-6 mm at the windward side and decreases approximate 6 mm at the leeward slope side.After terrain reduction,the U wind speed at low altitudes decreases by 2-4 m·s-1,and it's center position moves towards the southeast by 1-2 latitudes,leading to the southeastward movements of strong precipitation center.The vertical velocity along the longitude and latitude profiles show that the vertical ascending motion at the mountain windward side increases by 0.1×10-2 m·s-1;topography significantly enhances the water vapor convergence,especially at 850-700 hPa above the mountains.

Key words: Snowstorm, Terrain simulation, Diagnostic analysis

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