grwdamp Subroutine

   subroutine grwdamp
      use modglobal, only:ke, kmax, lcoriol, igrw_damp, geodamptime
      use modfields, only:up, vp, wp, thlp, qtp, u0, v0, w0, thl0, qt0, ug, vg, thl0av, qt0av, u0av, v0av
      use modmpi, only:myid
      implicit none

      integer k
      select case (igrw_damp)
      case (0) !do nothing
      case (1)
         do k = ksp, ke
            up(:, :, k) = up(:, :, k) - (u0(:, :, k) - u0av(k))*tsc(k)
            vp(:, :, k) = vp(:, :, k) - (v0(:, :, k) - v0av(k))*tsc(k)
            wp(:, :, k) = wp(:, :, k) - w0(:, :, k)*tsc(k)
            thlp(:, :, k) = thlp(:, :, k) - (thl0(:, :, k) - thl0av(k))*tsc(k)
            qtp(:, :, k) = qtp(:, :, k) - (qt0(:, :, k) - qt0av(k))*tsc(k)
         end do
         if (lcoriol) then
            do k = ksp, ke
               up(:, :, k) = up(:, :, k) - (u0(:, :, k) - ug(k))*((1./(geodamptime*rnu0))*tsc(k))
               vp(:, :, k) = vp(:, :, k) - (v0(:, :, k) - vg(k))*((1./(geodamptime*rnu0))*tsc(k))
            end do
         end if
      case (2)
         do k = ksp, ke
            up(:, :, k) = up(:, :, k) - (u0(:, :, k) - ug(k))*tsc(k)
            vp(:, :, k) = vp(:, :, k) - (v0(:, :, k) - vg(k))*tsc(k)
            wp(:, :, k) = wp(:, :, k) - w0(:, :, k)*tsc(k)
            thlp(:, :, k) = thlp(:, :, k) - (thl0(:, :, k) - thl0av(k))*tsc(k)
            qtp(:, :, k) = qtp(:, :, k) - (qt0(:, :, k) - qt0av(k))*tsc(k)
         end do
      case (3)
         do k = ksp, ke
            up(:, :, k) = up(:, :, k) - (u0(:, :, k) - u0av(k))*tsc(k)
            vp(:, :, k) = vp(:, :, k) - (v0(:, :, k) - v0av(k))*tsc(k)
            wp(:, :, k) = wp(:, :, k) - w0(:, :, k)*tsc(k)
            thlp(:, :, k) = thlp(:, :, k) - (thl0(:, :, k) - thl0av(k))*tsc(k)
            qtp(:, :, k) = qtp(:, :, k) - (qt0(:, :, k) - qt0av(k))*tsc(k)
         end do
      case default
         write(0, *) "ERROR: no gravity wave damping option selected"
         stop 1
      end select

      return
   end subroutine grwdamp