摘要
利用中尺度模式模拟结果和卫星、雷达、飞机、地面雨量站等观测资料,对2012年9月21日河北一次西风槽降水层状云系的宏微观结构和增雨条件进行了分析。结果表明:此次西风槽降水过程的影响系统为500 h Pa低槽和700 h Pa切变线,地面并没有伴随冷锋系统;西风槽云系不同部位具有不同云层性质和垂直结构特征,前端为高层冷云,云顶温度为-35℃,云体由冰相粒子和过冷水组成,没有暖云,有少量冷云降水;槽线附近云系为冷暖混合云,云顶温度为-20℃,云体最为密实,地面降水较强;槽后云系为低层液态水云,云顶温度为-5℃,有少量暖云降水;云水分布对应上升运动和高饱和区,高饱和区越深厚、上升运动越强,产生的云水值越大;利用模式过冷水含量、上升运动区、冰晶浓度、温度和逐时雨强对冷云催化增雨作业条件进行分析,槽线附近云系过冷水含量较多,存在强可播区,播撒高度为3.8~6.5 km,最适宜冷云播撒增雨作业。
A case of westerly trough precipitating stratiform cloud on 21 September 2012 is simulated using the mesoscale model MM5. Meso- and micro- structures of this precipitation are analyzed using simulations and observations of satellite,radar and aircraft. The large- scale weather systems of the precipitation are westerly trough on 500 h Pa and shear line on 700 h Pa. There is no obviously cold front at lowlevels. The cloud structures are different at different area of the cloud system. In the forepart,the cloud system composes of only supercooled cloud water and ice particles. There is a little cold cloud precipitation. The cloud top temperature is- 35 ℃.Near the line of westerly trough,the cloud is mixed phase with more ice,snow,graupel and more supercooled cloud water in cold area and more cloud water and rain water in warm area. The cloud top temperature is- 20℃. In the rear part,the cloud system composes of mostly warm cloud water. The cloud top temperature is- 5℃. There is a little warm cloud precipitation. The production of cloud water needs updraft and high saturation and is proportional to them. The seeding areas are distinguished by supercooled water,updraft,number concentration of ice,temperature and precipitation intensity. It is strongly seedable near the trough line due to the much more supercooled water. The seeding height is 3. 8 ~ 6. 5 km. These areas have good potential of artificial precipitation enhancement.
出处
《高原气象》
CSCD
北大核心
2015年第6期1699-1710,共12页
Plateau Meteorology
基金
中国气象科学研究院基本科研业务项目(2011Z005
2014R004)
公益性(气象)行业科研专项(GYHY20120625)
河北省科技计划支撑项目(14227003D)
国家自然科学基金项目(41275150
41275148)
关键词
层状云
微物理结构
增雨条件
数值模拟
Stratiform cloud
Microphysical structure
Cloud seedability
Numerical simulation
