摘要
使用常规气象观测资料、气候资料、NCEP 2.5°×2.5°再分析资料和自动气象站等资料,对江西50年来出现的18次持续3天10站次以上冻雨天气过程的形成特征进行分析,结果表明:(1)地面冷高压、阻塞高压、副热带高压、南支槽、850hPa切变线、地面辐合线(准静止锋)、温度锋区、700 hPa急流与湿舌等是强冻雨天气的主要影响系统,具有明显的天气系统配置特征;(2)在有利的天气形势背景下,强冻雨天气过程具有前期候(旬)增温特征。当前期平均温度极大值和平均温度值接近或超过历史同期水平时,极易出现持续性冻雨天气过程,72%以上的强冻雨天气过程与此相关;(3)18次强冻雨天气过程都存在逆温层特征,逆温层高度在850～700 hPa间,平均逆温差为1～5℃,最大10℃,同时地面温度在0℃以下或接近0℃;(4)700～850 hPa平均温差图上有3个温差中心,表明700 hPa高度上有明显的暖湿气流存在,89%的冻雨天气过程与之相关。
The conventional observation data,climatic data,NCEP 2.5°×2.5°reanalysis data and automatic observation data were employed to analyze the 18 severe freezing rain events over the past 50 years in Jiangxi Province.The results show that（1） the favorable influencing systems to the severe freezing rain were cold high,blocking high,subtropical high,trough in lower latitudes,shear line at 850 hPa,surface convergence line（quasi-stationary front）,temperature frontal zone,and jet stream and moist tongue at 700 hPa,and revealed the significant weather system patterns;（2） under favorable weather situations,severe freezing rain process presented characteristics of pentad（dekad） antecedent temperature increase. When the antecedent average maximum temperature and antecedent average temperature surpassed or approached to those in the same time of the past,the severe freezing rain event would occur very likely;（3） temperature inversions appeared between 850-700 hPa during the 18 severe freezing rain events,with 4- 5℃average temperature differences,upto a maximum of 10℃,and the surface air temperatures were lower than or close to 0℃;（4） there were three temperature difference centers between 700-850 hPa, meaning that there were warm and moist currents at 700 hPa and about 89%of the freezing rain events were related to these currents.
出处
《气象》
CSCD
北大核心
2011年第1期66-74,共9页
Meteorological Monthly
基金
中国气象科学研究院灾害天气国家重点实验室基金(2009LASW-A02)
江西省气象局重点科研项目(JXQX2008Z05
JXQX2009Z04)共同资助
关键词
冻雨
天气系统配置
前期候(旬)增温
逆温层结构
逆温区特征
freezing rain
weather system pattern
pentad（dekad） antecedent temperature increase
temperature inversion
temperature inversion area
