大气折射指数的结构参数与北方5～9月降雨的强相关现象

A Significant Relationship between Structure Parameter of the Refractive Index of Air and Rainfall in May-September over Northeast of China

基于中荷合作项目"建立关于荒漠化和粮食保障的中国能量与水平衡监测系统"(CEWBMS),在国家卫星气象中心和国家林业总局的支持下,乾安大孔径闪烁仪于1999年10月安装并正式运行。利用2000—2005年5～9月大孔径闪烁仪(LAS)观测的大气折射指数的结构参数C2n,采用独立性检验,证实了C2n的高低与未来32 h是否出现降雨(晴雨)存在显著相关关系。结合乾安气象站的有关气象观测数据,初步选择C2n白天值、C2n夜间值以及C2n的24 h变量作为预报依据,建立基于C2n预报未来32 h晴雨的预报流程;并利用2006年C2n的观测数据,依照预报流程对2006年进行了回报预报试验,正确率为42/47。

As part of Chinese Dutch cooperation on the CEWBMS（Chinese Energy and Water Balance Monitoring System） project,under the direction of China National Satellite Meteorological Center and State Forestry Administration（China National Desertification Monitoring Center）,the large aperture scintillometer was first installed in Qian′an of Jilin province,northeast of China in October 1999.Using the data collected from May to September in 2000-2005 with the large aperture scintillometer,it is confirmed that there is significant relationship between high/low C2n（structure parameter of the refractive index of air） and sunny/rain in next 32h by means of independent test.The sunny/rain forecasting process is given based on the data including C2n in the midday,C2n in the midnight,and its variation during 24 h.For C2n in 2006,a hind-forecast was done by this forecasting process.The result shows that the accuracy of the forecast is 42/47.