[Mitgcm-support] exch_uv changes for JAM

[mitgcm-support at dev.mitgcm.org]

Jean-Michel,

 If you get a chance can you try your 3d JAM run with these changes some
time

 changes go in each of

  o exch_uv_xyz_rs.F
  o exch_uv_xyz_rs.F
  o exch_uv_xy_rs.F
  o exch_uv_xy_rl.F

       CALL EXCH_RL( Uphi,
     I            OLw, OLe, OLs, OLn, myNz,
     I            exchWidthX, exchWidthY,
     I            FORWARD_SIMULATION, EXCH_UPDATE_CORNERS, myThid )
       CALL EXCH_RL( Vphi,
     I            OLw, OLe, OLs, OLn, myNz,
     I            exchWidthX, exchWidthY,
     I            FORWARD_SIMULATION, EXCH_UPDATE_CORNERS, myThid )

  changed to

       _EXCH_XYZ_R8 ( Uphi, myThid )
       _EXCH_XYZ_R8 ( Vphi, myThid )
  
  then same for uv_xy_rl except it goes to _EXCH_XY_R8

  For the _rs routines mapping is to _EXCH_XY[Z]_R4

 If that works then we won't need anything special in c38 to
 support JAM.

Chris