干旱气象 ›› 2026, Vol. 44 ›› Issue (4): 659-669.DOI: 10.11755/j.issn.1006-7639-2026-04-0659

• 论文 • 上一篇    下一篇

基于C波段双偏振雷达资料的甘肃中部一次强对流天气分阶段特征分析

姚瑞1(), 董宏昌1, 杨博成2, 张海耀1(), 刘海鹏1, 栾振斌1, 付文睿1, 李文举1   

  1. 1 甘肃省定西市气象局甘肃 定西 743000
    2 甘肃省白银市气象局甘肃 白银 730900
  • 收稿日期:2026-03-19 修回日期:2026-05-26 出版日期:2026-08-30 发布日期:2026-09-16
  • 通讯作者: 张海耀(1988—),男,甘肃定西人,高级工程师,主要从事灾害性天气预报预警及研究工作。E-mail: 748395345@qq.com
  • 作者简介:姚瑞(1990—),男,甘肃通渭人,工程师,主要从事强对流天气预报预警及研究工作。E-mail: 1527993272@qq.com
  • 基金资助:
    甘肃省自然科学基金面上项目(25JRRJ001);甘肃省自然科学基金基础研究计划项目(25JRRA851);中国气象局创新发展专项(CXFZ2025J042);甘肃省气象局气象科研项目人才专项(2627rczx-B-QNYXRC-11);甘肃省气象局青年基金项目(Qn2026-B-17);甘肃省气象局气象科研面上项目(ZcMs2025-G-32);甘肃省气象局气象科研面上项目(Ms2025-B-4)

Analysis of the phased characteristics of a severe convective weather event in central Gansu Province based on C-band dual-polarization radar data

YAO Rui1(), DONG Hongchang1, YANG Bocheng2, ZHANG Haiyao1(), LIU Haipeng1, LUAN Zhenbin1, FU Wenrui1, LI Wenju1   

  1. 1 Dingxi Meteorological Bureau of Gansu ProvinceDingxi 743000, Gansu, China
    2 Baiyin Meteorological Bureau of Gansu ProvinceBaiyin 730900, Gansu, China
  • Received:2026-03-19 Revised:2026-05-26 Online:2026-08-30 Published:2026-09-16

摘要:

为提高甘肃中部强对流天气预报预警能力,本文采用定西C波段双偏振雷达观测资料,结合ERA5再分析、探空及地面实况观测资料,对2024年5月24日甘肃中部一次典型强对流天气过程开展分阶段诊断分析。结果表明:此次过程发生在200 hPa高空急流分流辐散、500 hPa槽前正涡度平流与700 hPa低涡切变的叠加区域,高低空耦合形成深厚上升通道;冷高压东移加剧层结不稳定,由地面中尺度辐合线触发对流,过程伴随强降水、冰雹、大风多种灾害,持续时间较长。强冰雹阶段对应超级单体风雹,雷达观测到钩状回波、旁瓣回波,同时出现差分反射率(Differential Reflectivity,ZDR)柱、相关系数(Correlation Coefficient,CC)谷、差分相移率(Specific Differential Phase,KDP)“空洞”及ZDR弧,其中ZDR柱与CC谷较冰雹落地提前约20 min,后侧下沉气流造成极端大风。飑线阶段表现为弓形低质心回波,前沿水平反射率因子(Horizontal Reflectivity Factor,ZH)、ZDRKDP柱相互重叠;低层雨冰混杂区产生雷暴大风、短时强降水及局地小冰雹,纯大雨滴区以强降水为主,下沉重力外流形成直线大风。强降水阶段为中β层积混合型云团,以低质心回波为主要特征,ZDRKDP大值与CC小值区分布在4 km以下。混合型阶段强降水与小冰雹混合区ZDR、CC数值偏低,KDP数值偏大,并出现ZDR弧。

关键词: 甘肃中部, C波段双偏振雷达, 强对流天气, 偏振参量特征

Abstract:

In order to improve the forecast and early warning ability of severe convective weather in central Gansu, this study uses the observations from Dingxi C-band dual-polarization radar, combined with ERA5 reanalysis, sounding and ground observation data, to carry out phased diagnosis and analysis of a typical severe convective weather process in central Gansu on May 24, 2024. The results show that this event occurred in the superposition zone of 200 hPa upper-level jet divergence, 500 hPa positive vorticity advection ahead of the trough, and 700 hPa low-vortex shear. The coupling of upper- and lower-level systems produced a deep upward-motion channel. The eastward movement of the cold high intensified stratification instability. Convection was triggered by the surface mesoscale convergence line. This event was accompanied by multiple hazards including heavy precipitation, hail and strong winds, and lasted for a long time. During the severe-hail stage, the storm was a supercell. The radar observations captured hook echo and sidelobe echo, together with differential reflectivity (ZDR) column, correlation coefficient (CC) minimum, specific differential phase (KDP) “hole”, and ZDR arc. The ZDR column and CC minimum appeared approximately 20 min before hailfall, and the rear-flank downdraft generated extreme winds. During the squall-line stage, the storm exhibited bow-shaped low-centroid echo, with horizontal reflectivity factor (ZH), ZDR and KDP columns overlapping at the leading edge. Thunderstorm gales, short-term heavy precipitation and local small hail were produced in the lower-level rain-ice mixed zone. The large-raindrop-dominated zone was dominated by heavy precipitation, and the sinking gravity outflow formed straight-line winds. During the heavy-precipitation stage, the convective system was a meso-β-scale stratiform-convective mixed cloud cluster, mainly characterized by low-centroid echo, where high-value zones of ZDR and KDP as well as low-value zones of CC were distributed below 4 km. During the mixed-precipitation stage, the mixed zone of heavy precipitation and small hail exhibited low ZDR and CC values and high KDP values, with ZDR arcs occurring.

Key words: central Gansu, C-band dual polarization radar, strong convective weather, polarization parameter characteristics

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