山西春季层状云系数值模拟及与飞机探测对比

摘要

采用中国气象科学研究院（CAMS）中尺度云参数化模式对2010年4月20日山西省一次春季层状降水云系的宏微观结构，特别是垂直方向上的微物理结构进行了数值模拟和分析。利用携带云粒子探测设备的飞机对该次层状云系进行了两次云物理探测飞行，并将飞机探测所获取的数据和图像资料与数值模拟结果进行了对比研究。模拟结果显示：该次降水过程以层状冷云降水为主，云中过冷水含量丰富，云系存在明显的3层结构，地面降水主要来自于云中高层冰晶、雪、霰等冰相粒子的融化和低层云水的转化。数值模拟与飞机探测对比分析显示，高空温度、湿度和高度的配置两者基本一致，数值模拟不同高度的云粒子相态、垂直方向云水比含水量与飞机探测获取的云粒子图像和云液态水含量的垂直结构基本吻合，但数值模拟的云中各种水成物粒子出现的高度较飞机探测偏高。%The CAMS meso-scale cloud model is introduced and operationally applied since 2009 in Shanxi Prov-ince.The macro and micro structure of stratiform precipitation clouds,especially the vertical micro-physi-cal structure are simulated and analyzed for a spring stratiform precipitation process in Shanxi Province on 20 April 2010 using the model.Two cloud physical detection flights are carried out by using weather modi-fication plane with equipments of droplet measurement technologies (DMT)in the same place during the same period of the day.The data and images from flight detection and results of numerical simulation are compared and studied.Simulation results show that the precipitation process mainly comes from cold strat-iform cloud.The cloud contains a lot of supercooled water,and the thickness of the rich supercooled water layer is about 4000 meters.The temperature of the supercooled layer is about 0 to -40℃,and the ratio content of the supercooled cloud water is about 0.1—0.7 g·kg-1 with some ice crystals distributed une-venly.The structures of stratus precipitation cloud can be roughly divided into three layers.The first layer (upper layer)is mainly composed of ice crystals;snow,sleet and supercooled cloud water are mixed in the second layer (middle layer);and the third layer (lower layer)is mainly of liquid raindrops.The vertical distribution and the transformation of different hydrometers in different stages of the precipitation are ana-lyzed.The precipitation mainly comes from the melting of the ice phase particles such as ice crystals, snow,sleet and the transformation of liquid cloud droplets.Comparison of the numerical simulation results and the plane observation shows that the temperature and altitude relationship are in good agreement.The simulated vertical structure of the different cloud particles phase and the vertical distribution of the cloud liquid water ratio content are nearly the same as the vertical distribution of different cloud particles images and the cloud liquid water content of the flight detection.The difference is that the simulated height where various hydrometeors appears is higher than the actual flight detection.