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!
C
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C

      subroutine acv2gd 1,13
*
***s/r acv2gd  - Adjoint of cv2gd.
*
*
*Author  : Luc Fillion - CGD/NCAR - Jul 99
*Revision: Luc Fillion - ARMA/MSC - 14 Dec 2005. - Introduce option of regression w.r.t. vorticity
*
*     -------------------
**    Purpose: Used for LA-XD-Var analysis
*
*Arguments
*     none
*
      implicit none
#include "taglam4d.cdk"
#include "comlun.cdk"
#include "comdim.cdk"
#include "comct0.cdk"
#include "comcva.cdk"
#include "comsim.cdk"
#include "comgd0.cdk"
#include "comsp.cdk"
#include "comgrd_param.cdk"
*
      logical lltest_1tstp
      integer ji,jj,jk,ipt,jpt,jla,ik,jband,jm,ila
      integer jrow,jcol
      integer idim
      integer idum1,idum2,idum3,idum4
      real*8 zmin,zmax
      real  zinvpsi, zinvchi, zpsi, zchi
      real*8 zvortp(ni,nflev,nj)
      real*8 z3d(ni,nflev,nj)
      real*8 zvort(ni,nflev,nj)
      real*8 zdiv(ni,nflev,nj)
      real*8 zgdpsi(ni,nflev,nj)
      real*8 zgdchi(ni,nflev,nj)
      real*8 zu(0:ni+1,nflev,0:nj+1)
      real*8 zv(0:ni+1,nflev,0:nj+1)
      real*8 zsp(nla,2,nflev)
*
**
      lltest_1tstp = .false.
!
      zvort(:,:,:) = 0.0
      zdiv(:,:,:) = 0.0
      zgdpsi(:,:,:) = 0.0
      zgdchi(:,:,:) = 0.0
      zu(:,:,:) = 0.0
      zv(:,:,:) = 0.0
      zvortp(:,:,:) = 0.0
!      
      if(lltest_1tstp) then
        call putdx2('J')
        call getdx('J')
      endif
!
      do ji=1,ni
        do jj=1,nj
        do jk=1,nflev
          zu(ji,jk,jj)=ut0(ji,jk,jj)
          zv(ji,jk,jj)=vt0(ji,jk,jj)
        enddo
        enddo
      enddo
!
      do ji=1,ni
        do jj=1,nj
        do jk=1,nflev
          ut0(ji,jk,jj)=0.0
          vt0(ji,jk,jj)=0.0
        enddo
        enddo
      enddo
!
      call apc2UVg_c(zgdpsi,zgdchi,zu,zv)
!
      if(ldobal) then
        if(nanalvar.eq.4) then
          call zero(ni*nj*nflev,zvortp)
!          call abal2(zgdpsi,zgdchi,zvortp,lcva_helm)
        else
          call zero(ni*nj*nflev,zvortp)
          call abal(zgdpsi,zgdchi,zvortp,lcva_helm)
        endif
      endif
!
      write(nulout,*) 'acv2gd: lcva_helm = ',lcva_helm
!
      if(lcva_helm) then
        do jk=1,nflev
          do jj=1,nj
            do ji=1,ni
              ut0(ji,jk,jj) = zgdpsi(ji,jk,jj)
              vt0(ji,jk,jj) = zgdchi(ji,jk,jj)
            enddo
          enddo
        enddo
      else
        zvort(:,:,:) = 0.0
        zdiv(:,:,:) = 0.0
        call azd2pc_euclid(zvort,zdiv,zgdpsi,zgdchi)
        do jk=1,nflev
          do jj=1,nj
            do ji=1,ni
              ut0(ji,jk,jj) = zvortp(ji,jk,jj)+zvort(ji,jk,jj)
              vt0(ji,jk,jj) = zdiv(ji,jk,jj)
            enddo
          enddo
        enddo
      endif
!
      call denorm
!
      do ji=1,ni
        do jj=1,nj
        do jk=1,nflev
          zu(ji,jk,jj)=ut0(ji,jk,jj)
          zv(ji,jk,jj)=vt0(ji,jk,jj)
        enddo
        enddo
      enddo
!
      call spgda
      call anormsp
!
      if(nanalvar.eq.4) then
        call asqrtc2
        call asplat2sp
      else
        call sqrtc ! self adjoint in nanalvar.ne.4 case
      endif
!
      return
      end