吉林省雨凇气候特征及其天气分型

利用1980-2007年吉林省11个气象观测站常规观测资料，采用统计分析的方法，对共计100次雨凇天气的时空分布特征进行了分析。结果表明：吉林省雨凇天气南多北少，丘陵地带及长白山脉的迎风坡一带为雨凇的频发区。雨凇多发于冬初和初春，并且雨凇出现几率在减少。吉林省的雨凇天气的温度层结结构与中国南方省市雨凇的情况存在较大差异：吉林省雨凇天气并不存在融化层和逆温层等结构。通过对地面形势的分析，将雨凇天气分为低压后部型、高压前部型、低压南部型和低压型。它们的共同点是高空均有较深厚的后倾槽移过吉林省，温度槽落后于高度槽；近地面层先升温后降温，850 hPa相对湿度为70 %左右，而地面相对湿度均可达到80 %或以上。强雨凇天气主要发生在东南部地区，强雨凇天气出现时的地面及高空形势与一般的雨凇天气发生时的形势基本相似，但850 hPa和地面的相对湿度比一般情况偏大10 %左右。

Climatic features of glaze and its synoptic patterns in Jilin province

Based on the conventionally observed data at 11 weather stations from 1980 to 2007 in Jilin province, the spatial and temporal distributions of 100 glaze cases were analyzed by a statistical analysis method. The results in- dicate that the glaze weather often appears in the south of Jilin province, especially in hill area and the windward slope of Changbai Mountain and seldom in the north of Jilin province. The glaze weather mainly appears in the early winter and early spring, and the frequency of glaze events is reducing. The structure of vertical temperature stratification under glaze weather in Jilin province differs from that in other provinces in southern China where the melt layer and inversion layer for glaze weather occurred in Jilin province do not exist. By analysis of the ground situation, glaze weather was divided into four main patterns, i. e. the rear of low pressure, the front of high pres- sure, the south of low pressure and low pressure center. A deep backward-tilting trough at upper level moves over Jilin province, and temperature trough is behind the height trough. Temperature increases firstly and then decreases near ground layer. The relative humidity reaches about 70% at 850 hPa and 80% near the ground, respectively. Strong glaze weather often occurs in the southeastern region of Jilin province and its ground and upper situations are similar to the situations of general glazes,while its relative humidity is 10% more than that of the general glaze both at 850 hPa and near the ground.