!
! Global shared fg array takes the place of the scratch units in the 
!   multi-tasked model. fg carries 1st nflds fields of f-array at all 
!   latitudes (including boundary latitudes) and for previous and current 
!   iterations.
! zfldx = sum of nlevs for each field 1->nflds (nflds==69 in tgcm22)
! Fourth dimension is for current (ixtimec) and previous (ixtimep)
!   time steps.
!
      integer :: 
     |  ixtimec,   ! index to 4th dim of fg for current time step
     |  ixtimep,   ! index to 4th dim of fg for previous time step
     |  lat0,lat1  ! first and last latitude indices per task
!
! fg array in time-gcm: 76*3045*38*2 = 17.6 Mw
! fg array in tiegcm:   76* 895*38*2 =  5.2 Mw
      real :: 
     |  fg(zimxp,zfldx,-1:zjmx+2,2)    ! 76*3045*38*2 = 17.6 Mw
      common/fgcom/ fg,ixtimec,ixtimep,lat0,lat1
!
! Global shared fkmh and fnrh. These are defined in multi-tasked 
!   calls to hdif1, and referenced by hdif2.
!
      real ::
     |  fkmh(zimxp,zkmxp,-2:zjmx),          ! eddy viscosity
     |  fnrh(zimxp,zkmxp,-2:zjmx)           ! M/(T+T0)
      common/hdifcom/ fkmh,fnrh