subroutine init_grid(grid)
c
c*   Initialize max/mean/min grid for cloud clearing
c
c    INPUT & OUTPUT:
c                    grid(nlon,nlat,ntim,as)......Initialize this grid.
c                        (               1).......chn 8 Max grid initialized to -999
c                        (               2).......chn 8 sum grid set to 0
c                        (               3).......chn 8 count grid set to 0
c                        (               4).......chn 20 min grid set to 999
c
      implicit none
      include 'hirs1c.inc'

      integer i,j,k,l
      real    grid(nlon,nlat,ntim,as)

      do i=1,nlon
         do j=1,nlat
            do k=1,ntim
               do l=1,as
                  if(l .eq. 1) then
                     grid(i,j,k,l)=-999.
                  elseif (l .eq. 2) then
                     grid(i,j,k,l)=999. 
                  else
                     grid(i,j,k,l)=0.
                  endif
               enddo
            enddo
         enddo
      enddo

      return
      end