c Alternate grid Mapping Common
c ------------------------------
      common /gridalt_mapping/ nlperdyn,dpphys0,dpphys,
     .                                             dxfalt,dyfalt,drfalt
      integer nlperdyn(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,Nsy)
      _RL dpphys0(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nrphys,nSx,nSy)
      _RL dpphys(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nrphys,nSx,nSy)
      _RL dxfalt,dyfalt,drfalt