| 基于VDRAS资料探究河北中南部一次弓状强飑线的演变和机理 |
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| 引用本文： | 姬雪帅,杜晖.基于VDRAS资料探究河北中南部一次弓状强飑线的演变和机理[J].新疆气象,2023,17(3):44-51. |
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| 作者姓名： | 姬雪帅 杜晖 |
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| 作者单位： | 张家口市气象局,广东省气象局-广东省气象公共安全技术支持中心 |
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| 基金项目： | 广东省气象局青年基金（GRMC2021Q09）&张家口市气象局创新团队 |
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| 摘 要： | 利用常规气象资料、ERA5再分析资料、北京VDRAS资料以及雷达资料，对2021年7月31日发生在河北中南部的一次弓状强飑线过程进行分析。结果表明：（1）此次飑线过程发生在冷涡的背景下，500 hPa涡后的冷空气与850 hPa的暖脊叠加，建立了不稳定层结，在地面辐合线附近触发。（2）雷达回波由分散的对流单体合并加强，强弓形出现时，最大强度值超过55 dBZ，存在径向速度大值区和中层径向辐合等特征，这些都预示地面大风的出现，而回波悬垂预示冰雹出现。（3）雷达反演的风场可以显示飑线的水平和垂直结构，能清楚地指示飑线的出流、入流以及辐合区，对指示飑线不同部位的发展趋势有重要指示意义。（4）地面风场辐合导致雷暴单体触发，雷暴单体在不稳定的大气层结中获得快速发展，发展过程中0～3 km的垂直风切变逐渐增强，低层形成冷池，热力不均匀区域扩大，沿着扰动温度梯度大值区与风场辐合区，新生对流向东向南传播，分散对流单体合并演变为飑线。（5）从飑线发展阶段的热动力结构分析中发现，由倾斜上升气流与下沉气流形成垂直环流，下沉气流增强时，冷池效应增强，低层环境垂直风切变也增强，环境条件的改变是飑线发展的结果，同...
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| 关 键 词： | 弓状飑线 VDRAS 冷池 雷达回波 风场反演 |
| 收稿时间： | 2021/12/20 0:00:00 |
| 修稿时间： | 2022/5/9 0:00:00 |
Evolution and Development Mechanisms of an Arc-Shaped Strong Squall Line Occurring in the center-south part of Hebei Province based on VDRAS data |
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| JI Xueshuai and Du Hui.Evolution and Development Mechanisms of an Arc-Shaped Strong Squall Line Occurring in the center-south part of Hebei Province based on VDRAS data[J].Bimonthly of Xinjiang Meteorology,2023,17(3):44-51. |
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| Authors: | JI Xueshuai and Du Hui |
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| Institution: | Zhangjiakou Meteorological Bureau, |
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| Abstract: | Based on conventional meteorological data, ERA5 reanalysis data, Beijing VDRAS data and radar data, an arc-shaped strong squall line occurred in center- south part of Hebei province on July 31, 2021 was analyzed. The results showed that :(1) the squall line occurred under the background of cold vortex, and the cold air behind the 500hPa vortex superimposed with the 850hPa warm ridge, which established unstable stratification and triggered near the ground convergence line. (2) During the squall line, the vertical wind shear of 0 ~ 3km gradually increased, and the local convergence of the surface wind field led to the formation of a cold pool after the thunderstorm cells were triggered. The thermal inhomogeneity area expanded and developed along the large value area of the disturbed temperature gradient and the convergence area of the wind field. The thermal dynamic structure of squall line was analyzed. It was found that vertical circulation was formed by inclined updraft and downdraft, the downdraft was strengthened, the cold pool effect was enhanced, and the low-level environmental vertical wind shear was also enhanced. (3) The strongest reflectivity factor of radar echo is generally over 55dBz, accompanied by strong bow echo, large value area of radial velocity and radial convergence of middle layer, etc. These characteristics all predict the occurrence of surface gale, and echo overhang indicates the occurrence of hail. (4) The wind field retrieved by radar can display the horizontal and vertical structure of the squall line, clearly indicate the outflow, inflow and convergence area of the squall line, and have important indicative significance to indicate the development trend of different parts of the squall line. |
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| Keywords: | arc-shaped VDRAS cold pool radar echo wind retrieved |
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