2022年初湖南两次灾害性大暴雪成因分析  

Analysis of Causes of Two Disaster Heavy Snowstorms in Hunan In Early 2022

作　　者：胡燕 刘红武 赵恩榕 王青霞 刘焕乾 陈红专[4] HU Yan;LIU Hongwu;ZHAO Enrong;WANG Qingxia;LIU Huanqian;CHEN Hongzhuang(Hunan Meteorological Observatory,Changsha 410118,China;Hunan Key Laboratory of Meteorological Disaster Prevention and Reduction,Changsha 410118,China;Hunan Meteorological Observation Technology Support Center,Changsha 410118,China;Huaihua Meteorological Observatory of Hunan Province,Huaihua 418000,China)

机构地区：[1]湖南省气象台,湖南长沙410118 [2]气象防灾减灾湖南省重点实验室,湖南长沙410118 [3]湖南省气象技术装备中心,湖南长沙410118 [4]湖南省怀化市气象局,湖南怀化418000

出　　处：《灾害学》2023年第1期80-87,共8页Journal of Catastrophology

基　　金：中国气象局预报员专项(CMAYBY2020-085);2021年中国气象局创新发展专项(CXFZ2021Z033,CXFZ2021J020);湖南省科技厅重点领域研发计划项目(2019SK2161);湖南省气象局重点项目(XQKJ22A004,CXFZ2022-ZDZX01,XQKJ22C007);湖南省气象局短平快项目(XQKJ22B005);湖南省业务能力建设(NLJS14)。

摘　　要：2022年2月6—7日(简称“2.6”过程)和21—22日(简称“2.22”过程)湖南出现了两次灾害性大暴雪天气过程,利用多源观测资料与再分析资料,通过HYSPLIT v4.9(空气质点轨迹追踪模式)及聚类算法,从环流背景、温度条件及水汽特征探讨两次强降雪特征及成因差异。分析表明:(1)“2.6”过程降雪持续时间短,降雪时段集中,小时雪量大;“2.22”过程强降雪持续时间长,累积降雪量大,部分站点雪深破历史极值,具有显著极端性。(2)两次过程均受南支槽影响,其中“2.22”过程南支槽更深厚,地面上两个强大的高压中心持续补充冷空气,造成长时间的地面低温。(3)温度平流差异明显,“2.6”过程主要受高空和地面冷平流共同作用造成温度下降,“2.22”过程由中层冷平流驱动冷空气下传,长时间维持深厚冷垫和10 m/s以上的边界层东北回流是造成持续性强降雪的重要成因。(4)两次大暴雪过程的主要水汽通道均是来自阿拉伯海的西南输送带,另外,还有一支来自西太平洋的偏东水汽输送带,经南海转为偏南路径向北输送至暴雪区,这也是湖南冬季暴雪需要特别关注的水汽传输路径。Two heavy snowstorms that occurred in Hunan from 6 to 7 and from 21 to 22 February 2022.Using surface weather observations,wind-profile radar data and NCEP reanalysis data,and introducing on HYSPLITv4.9(the trajectory model of the air parcel)and cluster method,the similarities and differences of the circulation characteristics,temperature advection and the water vapor condition are comparatively analyzed.The results showed:In“2.6”process,the snowstorm period was concentrated,and the hourly snowstorm was large.In“2.22”process,it was extremely that continuous heavy snowstorm leaded to the maximum daily snowstorm intensity in Hunan,and snow cover depth broke the historic record of some stations.It was extremely.The two processes were affected by southern branch trough.The height-blocking center of was obviously eastward in“2.22”process,the longitude of the southern branch trough was larger,and the two split height centers on the surface complement,leading to long time low temperature,which may be the main synoptic cause of extreme snowstorm.The characteristic of temperature advection were different in the two snowstorms,the temperature of“2.6”process decreases due to the combined action of high-altitude and ground cold advection.The“2.22”process maintained a rare deep cold pad and northeastern wind backflow in the whole stage in Hunan.The middle-level cold advection drove the cold air to expand to the ground,and the northeast backflow of the boundary layer reached the jet standard.The combined action caused long-term low temperature and snow depth.The main water vapor channel of the two heavy snowstorm processes in Hunan was the southwest warm and humid air flow from the Arabian Sea.In addition,there was an easterly water vapor transport belt from the western Pacific,which was directly transported to the Hunan snowstorm area by the southerly air flow from the South China Sea.This was also the water vapor transport path that needs special attention in Hunan winter snowstorm.

关 键 词：灾害性大暴雪 大气环流 温度条件 水汽传输 成因 

分 类 号：X43[环境科学与工程—灾害防治] X915.5[天文地球—地质学] P694