计算各种气象物理量，包括散度、涡度、螺旋度、垂直速度、水汽通量、比湿、假相当位温、k指数等的grads 程序，-Calculate various meteorological physical quantity, including divergence, vorticity, helicity, vertical velocity, water vapor flux, specific humidity, pseudo-equivalent temperature, k index grad

利用grads计算ncep-fnl资料的的水汽通量及水汽通量散度(The calculation of water vapor flux and water flux divergence about the ncep- FNL data by using grads)