【摘要】 利用咸宁MP-3000A地基微波辐射计探测资料对2010年4月12日发生在咸宁的一次冰雹天气过程进行了监测分析。结果表明:(1)在这次冰雹天气过程中,冰雹云中上升气流非常强盛,引起云底高度剧烈波动,同时将底层空气的感热和潜热向上输送导致等温线上抬,并伴随贝吉隆增长和过冷水滴与冰晶消耗等过程,由于这些宏观和微观过程使得整层水汽与液态水含量连续出现下降和上升过程,产生了多峰结构;(2)在4.2—8km高度过冷层的冰雹云中,08时40分—13时的固、液、气混合相态变化非常复杂,过冷水滴与冰粒子消耗过程、贝吉隆过程和过冷水滴与冰晶增长过程交替出现,产生了相对湿度在6km以下低于80%的区域,且液态水含量在4.2—8km高度处出现0.7—1.8g/m3的大值区,从而形成了冰雹生长过程中交替干、湿增长生长环境,非常有利于冰雹粒子群快速累积以及分层增长;(3)利用微波辐射计资料计算分析了MKI、KI、TT和HI四个不稳定指数,这些指数对强对流天气有很好的指示作用,并对强对流天气有一定的临近预警潜力,若选取KI≥38作为该地区强对流天气预警指标,可以提前45min预警第1次降雹强对流天气,且分别提前20、40和42min预警第2、3、4个对流单体影响该地区。更多还原

【Abstract】 A hailstorm event in the middle basin of the Yangtze River on 12 April 2010 is observed by the ground microwave radiometer located at Xianning,Hubei Province,China.The results show:(1) In the hail cloud very strong the updraft caused volatility of the cloud base height,while continuous upward transport of low-level air sensible heat and latent heat lead isotherms to upward lifting,with the other processes associated with the Bergeron effect and ice crystal depletion.Because of these macro and micro processes,the integrated water vapor and integrated liquid water content experinced continuous decline or rise,resulting in a multi-peak structure.(2) It is clear that,in the 4.2-8 km supercooled layer of hail cloud,dynamic exchange among water solid,liquid and vapor phases is very complex during the period of 08:40-13:00 UTC,characterized by alternating among droplet-ice depletion,Bergeron process and droplet-ice growth,causing an area of relative humidity less than 80% below 6 km with the liquid water content large value area of 0.7-1.8 g/m3 occuring in the height of 4.2-8 km,which results in forming the hail growth environment of alternating between wet and dry growth,conducive to the hail particles rapid accumulation and growth in stratified groups.(3) Using the microwave radiometer data to calculate the four instability indices MKI,KI,TT and HI,we find these indicators have a good indication to severe convective weather,and show a potential to severe weather nowcasting.If KI ≥38 is selected as early warning indicators of severe convective weather in the region,early warning can be issued 45 min ahead for the first hail severe convective weather,and it can issue early warning of the 2nd,3rd,4th convective cell that will impact the region,20 min,40 min and 42 min ahead of time,respectively.更多还原