1. Precipitation Unit: mm

2. Data files:
   (1). date: 1985-1996   
   (2). yy.sum: annual total precipitation (mm)
   (3). yymm.sum: monthly total precipitation (mm)
   (4). yy1-yy2.mean: annual mean precipitation from yy1 to yy2 (mm)
   (5). latitude and longitude data of grids:
        lat.dat: latitude data of grids
        lon.dat: longitude data of grids
   (6). topo.dat: terrain data of Greenland ( meter ) 

3.  Model parameters: 
   (1). The number of grid points is 67x69
        x direction: 67;   y direction: 69
   (2). The grid space = 50km
   (3). Central latitude and longitud: ( 71.5N,-40W)
        Note: for longitude dat:  
           0 - 180E, the numbers is positive  
           0 - 180W, the numbers is negative

   (4). Region: (region.jpeg)

        (1,69)      N          (67,69)
          -----------------------
          |                     |   
          |                     |   
          |                     |   
          |                     |   
        E |          C          | W
          |                     |   
          |                     |   
          |                     |   
          |                     |   
          |                     |   
          |                     |   
          -----------------------
         (1,1)       S          (67,1)

    (5). The method to calculate precipitation: Omega equation
    (6). Stereographic projection

4. Data format: 10f8.2 ( *.mean *.sum *.dat )

   read(10'(10f8.2)')((a(i,j),i=1,m),j=1,n)  ! m=67,n=69

5. References
   Qiu-shi Chen, David H. Bromwich, and Lesheng Bai, 1997: Precipitation over
   Greenland Retrieved by a Dynamic Method and Its Relation of Cyclonic 
   Activity. Journal of Climate, 10,839-870,1997.