池州地区冬半年固态降水及其环流背景统计特征  

Statistical Characteristics of Chizhou Solid Precipitation and Its Circulation Background in Cold Season

作　　者：孙卉 吴照宪 刘玉林 田慷 SUN Hui;WU Zhaoxian;LIU Yulin;TIAN Kang(Chizhou Meteorological Bureau,Chizhou 247100,China)

机构地区：[1]池州市气象局,安徽池州247100

出　　处：《沙漠与绿洲气象》2022年第4期104-111,共8页Desert and Oasis Meteorology

基　　金：2020年安徽省气象局预报员专项项目(KY202008)。

摘　　要：基于2003-2018年冬半年(11月-次年3月)观测资料,采用T-mode主成分客观分析法(TPCA)等进行固态降水与环流背景的统计分析。结果表明:池州172个固态降水日,主要月份固态降水出现的频率分别是44.8%(1月)、27.9%(2月)和16.3%(12月)。雨雪转换、纯雪和冻雨3类天气占比分别为55.2%、41.3%和3.5%。环流形势可划分为一槽一脊型(Ⅰ型)、纬向波动型(Ⅱ型)和两槽一脊型(Ⅲ型),其中Ⅰ型占比最多,Ⅱ型次之,Ⅲ型较少。Ⅰ~Ⅲ型分别代表北方冷空气从中路、西路和东路南下,池州固态降水过程主要受中路冷空气影响。Ⅰ型气温最低,出现固态降水概率最高,是其他形势的3倍以上;Ⅱ型气温最高,出现固态降水概率最低。除Ⅲ型外,纯雪过程的中低层温度均较雨雪转换过程低2.0℃左右。925 hPa温度在雨雪转换过程与850 hPa基本相同,一般在-4.0~-5.0℃,在纯雪过程中则比850 h Pa高1.0℃左右。1 000 hPa温度在雨雪转换过程基本在0℃附近,纯雪则在0℃以下。池州固态降水的中低层环流特征是:925 hPa为东北风,850 hPa存在气旋性环流,700 hPa有12.0 m/s左右的偏南风急流、水汽通量及水汽通量散度大值中心。池州冬半年固态降水一般属于冷锋大尺度降水,层结稳定,锋区位于700 hPa以下,低层有冷平流,切变线一般位于850~800 h Pa。Based on the observational data in cold season(from November to March) during 2003-2018,T-mode Principal Component objective Analysis(TPCA) and other statistical methods were used to analyze the relationship between solid precipitation and synoptic.The results demonstrated that solid precipitation mainly occurred from December to February,accounting for 16.3%,44.8% and27.9%,respectively in the total 172 solid precipitation days in Chizhou.Solid precipitation included three types:rain-snow phase change,pure snow and freezing rain,accounting for 55.2%,41.3% and3.5%,respectively.The synoptic circulation can be divided into three types:one-trough one-ridge type(Type Ⅰ),zonal wave type(Type Ⅱ)and two-trough one-ridge type(Type Ⅲ).Type Ⅰ accounted for the most,type Ⅱ took the second place and type Ⅲ was the least.The paths of clod air of Type Ⅰ~Ⅲ were middle,west and east path,respectively.The solid precipitation weather in Chizhou mainly occurred in middle path(Type Ⅰ).The highest frequency of solid precipitation occurred Type Ⅰ,more than 3 times of the other types,because of the lowest temperature.By contrast,the highest temperature and the minimum frequency of solid precipitation occurred in Type Ⅱ.Except for Type Ⅲ,temperature in the middle-low level in pure snow weather was approximately 2.0 ℃ lower than that in phase change weather.Temperature at 925 and 850 h Pa was approximately equal in phase change weather,generally between-4.0 ~-5.0 ℃,while the former was 1.0 ℃ higher than latter in pure snow weather.Temperature at 1 000 h Pa was approximately 0 ℃ in phase change weather,and was below 0 ℃ in pure snow weather.The middle-low level synoptic circulation of Chizhou solid precipitation were as follow:Northeasterly wind at 925 h Pa,cyclonic circulation at 850 h Pa,together with about 12.0 m/s Southly jet,the large value center of water vapor flux and water vapor flux convergence at 700 h Pa.Solid precipitation in cold season was generally caused by large-scale precipitation with s

关 键 词：固态降水 T-mode主成分分析法 环流分型 高低空配置 

分 类 号：P466[天文地球—大气科学及气象学]