冷涡背景下两次飑线过程对比分析

Comparative Analysis of EA and BL Squall Line Processes under the Background of Cold Vortex

摘要: 本文利用1˚ × 1˚ 6 h的NCEP FNL资料，并使用WRF V3.1数值模式模拟，选取发生地理位置均在40˚N、118˚E附近，冷涡背景下的两次飑线过程的潜势条件进行对比分析。得到以下结论：1) EA型飑线个例的冷涡是极地高空冷槽加深形成切断低压，继而发展形成冷涡，BL型飑线个例的冷涡是蒙古冷槽加深切断形成的。2) EA型飑线个例比BL型飑线个例发生的环境场更不稳定。3) EA型飑线个例发生时水汽条件较好。4) EA型个例在飑线形成时有明显的气压，露点温度，风速的骤变，BL型较弱。

Abstract: In this paper, we make a comparative analysis of EA and BL squall line processes under the back-ground of cold vortex with the same geographical location at 40˚N and 118˚E, the NCEP FNL data and TBB data are used, and use the WRF V3.1 numerical model to simulate the results. We get the following conclusion: 1) The EA type cold vortex is a deep high-altitude cold trough deepening to form a cut-off low pressure, and then developing to form a cold vortex. The BL type cold vortex is formed by deepening and cutting the Mongolian cold trough; 2) The EA squall line is more unstable than the BL squall line; 3) The water vapor condition is better when the EA squall line occurs; 4) In the case of the EA type, there is a significant air pressure at the formation of the squall line, the dew point temperature, the sudden change of the wind speed, and the BL type is weak.