江西省冻雨垂直温度层结分析及预报  

Analysis of vertical temperature stratification of freezing rain and its prediction in Jiangxi province

作　　者：郑婧[1] 许爱华[1] 许彬[1] 

机构地区：[1]江西省气象台,江西南昌330046

出　　处：《气象与环境学报》2014年第4期49-56,共8页Journal of Meteorology and Environment

基　　金：中国气象局新技术推广项目(CMATG2009MS03);江西省科技厅科技支撑计划"江西冻雨大雪预报方法及防御对策研究"(2010BSB02300)共同资助

摘　　要：利用1960—2013年江西省89个气象观测站常规观测资料,采用统计分析和插值处理方法,对江西省106次冻雨过程垂直温度层结进行分析,并建立冻雨预报思路。结果表明:江西省冻雨发生通常伴随1000—850 hPa剧烈降温和700 hPa增温,925—700 hPa存在明显逆温。融化层是冻雨发生的必要条件,江西省冻雨87.7%样本融化层位于700 hPa,9.4%样本融化层位于850 hPa;一般以1000 hPa温度<1.0℃、925 hPa和850 hPa温度<-2.0℃及700 hPa温度≥0.0℃作为江西冻雨预报的温度阈值标准,同时也应注意融化层位于850 hPa的情况。地面气温越低,越有利于冻雨形成,冻雨发生时最低气温为0.0℃以下,平均气温为1.0℃以下。冷暖空气持续在27°—28°N交汇,且鄱阳湖以南至抚河流域平均气温<1.0℃和最低气温<0.0℃出现比其他地区多,造成该区域冻雨发生频次比其他地区明显偏多。另外,通过大气逆温层结、地面气温与冻雨的对应关系,建立基于模式资料和常规观测资料的冻雨自动诊断方法。Based on conventionally observational data at 89 weather stations in Jiangxi province from 1960 to 2013,characteristics of vertical temperature stratification for 106 freezing rain cases were analyzed in terms of methods of a statistical analysis and a interpolation,from which a prediction method was established.The results in-dicate that temperature decreases sharply from 1000 hPa to 850 hPa and increases on 700 hPa when freezing rain happens.There is significant inversion layer between 925 hPa and 700 hPa.Warm layer is essential to freezing rain,and it is located in 700 hPa for 87.7% cases and in 850 hPa for only 9.4% cases.Temperature threshold standard for freezing rain prediction is defined in Jiangxi province i.e.,temperature is 〈1.0 ℃ at 1000 hPa,〈 -2.0 ℃at 925 hPa and 850 hPa,and≥0.0 ℃at 700 hPa.However,it should be vigilant when warm layer is located in 850 hPa.The lower ground temperature is,the more favorable formation of freezing rain is.Freezing rain occurs when the minimum temperature is below 0.0 ℃ and average temperature is below 1.0 ℃.Cold and warm air converges continuously over the areas from 27＆#176;N to 28＆#176;N.In addition,the frequency of average temperature be-low 1.0 ℃and minimum temperature below 0.0 ℃in the south of the Poyang Lake to Fuhe River are significant-ly higher than those in other areas,which makes freezing rain in these areas more often than in others.According to the corresponding relationship of freezing rain with atmospheric inversion temperature stratification and ground air temperature,an automatic diagnostic method is developed based on the data from the model and observational stations.

关 键 词：冻雨 垂直温度层结 逆温 地面气温 预报方法 

分 类 号：P468.024[天文地球—大气科学及气象学]