基于多种探测资料对武汉一次短时暴雪天气的监测分析

Analysis on a Short-Time Snowstorm Weather in Wuhan Based on Variety of Monitor Data

利用Thies Clima激光雨滴谱仪、MP3000A微波辐射仪、多普勒雷达和人工加密观测资料,分析了2011年2月12日武汉一次暴雪天气过程的演变特征。结果表明:(1)在这次短时暴雪过程中,先后出现了降雨、雨夹雪和纯降雪3个阶段,激光雨滴谱仪监测到该降雨阶段的雨滴谱较宽,最大直径达4.5mm,数浓度比较小,为2～5 429个.m-3.mm-1,雨滴谱型呈双峰型分布特点;(2)微波辐射仪对水汽相态监测显示,08:12-09:34(世界时)期间在1.5～3.5km过冷层比湿维持14～16g.kg-1大值区,之后迅速由雨夹雪过程(仅16min)过渡到纯降雪阶段,在65min内武汉站降雪量达到5.035mm,占整个降雪量的80%以上;(3)雷达反射率因子与粒子谱宽和数浓度密切相关,若后两者越大则对应的雷达回波强度也越大;同时还发现,与微波辐射仪反演的水汽密度、激光雨滴谱仪测得的降水强度也有较好的对应关系,若将这些结合起来对降水的相态变化、强度、量级和持续时间有很好的监测能力。

A short-time snowstorm event in Wuhan on 12 Feburary 2011 is analyzed using Thies Clima laser precipitation monitor（TCLMP）,MP3000A microwave radiometer,Doppler radar and artificial observation data.The results show that：（1） It has gone through three stages in the heavy snowstorm process,such as rain,sleet and snow.At the rain stage,the TCLMP monitored a wide raindrop spectrum,its maximum diameter is 4.5 mm,the number concentration is small（only 2 to 5 429 m-3·mm-1）,which has a bimodal distribution,and so on.（2） Dynamic exchange of vapor phase has been observed by using Microwave radiometer,the specific humidity in the 1.5~3.5 km heights appears a range of 14~16 g·kg-1 large value area at 08：12-09：34（UTC）,and the sleet process is very short,only 16 min,and it quickly switched to the pure snowfall stage,then snowfall in Wuhan reachs 5.035 mm within 65 min,accounting for more than 80% of the entire snowfall.（3） The Doppler radar reflectivity corresponded well to particle spectral width and number concentration,the greater of the latter two is,corresponding to the greater strength of the radar echo is,which closely relate to water vapor density of microwave radiometer and rainfall intensity of TCLPM.If combining them,it will has a very good monitoring capabilities of dynamic exchange for precipitation phase,rainfall intensity,magnitude and duration.