湖北省冻雨天气特征及其判定方法研究

Characteristics and Discrimination Method of Freezing Rain Weather in Hubei Province

利用常规地面气象站多时次气象要素和天气现象观测资料,以及武汉、宜昌和恩施的探空资料,对1998—2014年湖北地区冻雨天气的主要环流背景进行了分析,归纳了冻雨发生发展过程的气象要素和大气层结特征,给出了基于正负能量面积的冻雨发生定量化判断方法。结果表明：乌山阻高型和贝湖阻高型是导致湖北省出现冻雨天气的两种主要天气形势;2005年和2月是冻雨主要发生的年份和月份;共存在3种典型的气温层结演变特征,其中＂暖雨-冻雨-固态＂的气温层结演变最易导致持续时间长、影响范围大的冻雨天气;基于正负能量面积的冻雨判定方法为：3层层结时,正能量面积（ASP）小于80℃·hPa,负能量面积（A_（SN））小于400℃·hPa,且正负能量关系为（5.71ASP-257.14）≤ASN≤（6.25ASP＋200）;2层层结时,ASP为350-650℃·hPa,AS）为200-400℃·hPa,且正负能量关系为（ASP-350）≤ASN）≤（ASP-100）。

Based on the surface meteorology observation data,weather phenomena records,and radiosonde data,the circulation backgrounds of freezing rainfall in Hubei from 1998 to 2014are analyzed,and the characteristics of variations of meteorological elements and atmospheric stratifications are summarized.The discrimination criteria of freezing rain weather based on the relationships between positive and negative energy areas are given.The results show that the Urals blocking high and Lake Baikal blocking high are two major circulation patterns leading to the occurrence of freezing rainfall in Hubei Province.There are mainly three variation patterns of temperature stratification,in which the pattern of the transmission from warm rainfall to freezing rainfall then to solid precipitation has the longest duration and the largest influenced area.As for the discrimination criteria based on positive/negative energy for the occurrence of freezing rainfall：when there are the three-layer stratification,the positive energy area（ASP）is less than 80℃·hPa and negative energy area（A_（SN））is less than 400 ℃·hPa and there is the relationship between ASP and ASNof（5.71ASP-257.14）≤A_（SN）≤（6.25A_（SP）＋200）;when there is the two-layer stratification,A_（SP） is350 to 650℃·hPa,and A_（SN） is 200 to 400℃·hPa,and there is the relationship between A_（SP） and A_（SN） of（ASP-350）≤A_（SN）≤（ASP-100）.