摘要
利用探空资料、地面观测资料和欧洲中心再分析资料,对2022年2月19—22日云南区域性寒潮天气特征和形成原因进行诊断分析.结果表明:此次寒潮过程前期日最高气温降幅显著,为降温寒潮;后期出现持续性低温和降雪,为低温寒潮;槽后西北气流引导冷空气沿地面高压东侧向西回流,配合切变线推动地面冷锋向云南推进,是造成寒潮天气的主要影响系统;低层冷平流输送加强,前期气温偏高导致降温幅度进一步加大,有利于降温寒潮天气的出现;大气低层辐合区深厚,中层辐散强度增强,垂直上升运动发展,配合南支槽前西南急流的水汽输送,全省出现降水天气;地面温度接近0℃的区域雨雪相态复杂,但零度线接地,低层相对湿度较小,冰晶失去融化机制,是造成降雪天气的主要原因.
Based on radiosonde data,ground observation data and ECMWF reanalysis data,the characteristics and causes of the regional cold wave in Yunnan from February 19 to 22,2022 were diagnosed and analyzed.The results showed that the daily maximum temperature decreased significantly in the early period of the cold wave,which was a cooling-type cold wave,and sustained low temperature and snowfall in the later period was a low temperature cold wave.The northwest air flow after the trough guided the cold air to return to the west along the surface high pressure,and pushed the surface cold front to Yunnan with the shear line,which was the main influence system causing the cold wave weather.The cold advection transport at low level was strengthened,and the temperature drop was further increased due to the high temperature in the early stage,which was conducive to the occurrence of cold wave.The convergence area in the lower layer of the atmosphere was deep,the divergence intensity in the middle layer was enhanced,the vertical upward movement developed,and with the water vapor transport of the Southwest jet in front of the South trough,there was precipitation in Yunnan Province.In the area where the ground temperature is close to 0℃,the phase of rain and snow was complex,but the zero point line was grounded,the relative humidity of the lower layer is small,and the ice crystal loses the melting mechanism,which is the main reason for the snow weather.
作者
许彦艳
连钰
闵颖
周泓
XU Yanyan;LIAN Yu;MIN Ying;ZHOU Hong(China Meteorological Administration Hydro-Meteorology Key Laboratory,Beijing 100081,China;Yunnan Meteorological Observatory,Kunming 650034,Yunnan,China;Research Center for Disastrous Weather over Hengduan Mountains&Low-Latitude Plateau,China Meteorological Administration,Kunming 650034,Yunnan,China;Yuxi Meteorological Bureau,Yuxi 653100,Yunnan,China)
出处
《云南大学学报(自然科学版)》
北大核心
2025年第4期677-685,共9页
Journal of Yunnan University(Natural Sciences Edition)
基金
云南省科技计划项目(202203AC100006)
国家自然科学基金(42375043)
中国气象局水文气象重点开放实验室开放研究课题(23SWQXZ008).
关键词
寒潮
降温
降雪
成因分析
cold wave weather
cooling
snowfall
impact forecast
