[Mitgcm-support] RE: help setting up tank experiement

[mitgcm-support at dev.mitgcm.org]

Jean-Michel,

  I think Sai's problem must have to do with
lopped cells and his Bathy.bin not being
exact - however I though lopping was off by default
and I can't see in the code how it would happen.
But the behavior after that is very consistent
with there being a really silly thin cell
somewhere.

Sai - Jean-Michel is in 14-1422 I think.

Chris

-----Original Message-----
From: Sai Ravela [mailto:ravela at MIT.EDU]
Sent: Monday, October 28, 2002 12:36 PM
To: Chris Hill; jmc at plume.mit.edu
Subject: RE: help setting up tank experiement


Hi the problems with Ro_surf are here, in ini_masks_etc.F

        DO J=1-Oly,sNy+Oly
           DO I=1-Olx,sNx+Olx
              tmpfld(I,J,bi,bj) = 0.
              ksurfC(I,J,bi,bj) = Nr+1
              maskH(i,j,bi,bj) = 0.
              Ro_surf(I,J,bi,bj) = R_low(I,J,bi,bj)
              DO K=Nr,1,-1
                 Ro_surf(I,J,bi,bj) = Ro_surf(I,J,bi,bj)
     &                + drF(k)*hFacC(I,J,K,bi,bj)
                 IF (hFacC(I,J,K,bi,bj).NE.0.) THEN
                    ksurfC(I,J,bi,bj) = k
                    maskH(i,j,bi,bj) = 1.
                    tmpfld(i,j,bi,bj) = tmpfld(i,j,bi,bj) + 1.
                 ENDIF
              ENDDO
 WRITE(msgBuf,'(I4, I4, I4, I4, 1PE30.15,  1PE30.15)') I,J,bi,
     &                 bj,R_low(I,J,bi,bj), Ro_surf(I,J,bi,bj)
      CALL PRINT_MESSAGE( msgBuf, standardMessageUnit,SQUEEZE_RIGHT,1)

           ENDDO
        ENDDO

Here for example is what happens when the proper depth of -0.15m is
encountered in R_low.
What do drF and hFacC do?....Since I am new to this, please let me know what
the issue may be
if you have time to spare, but I'll try and figure it out in a bit.

Sai

			    I	   J	 BI  BJ		R-low					Ro-surf
(PID.TID 0000.0001)   52   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   53   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   54   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   55   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   56   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   57   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   58   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   59   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   60   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   61   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   62   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   63   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   64   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   65   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   66   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   67   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   68   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   69   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   70   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   71   3   1
    -1.500000000000000E-01        -2.428612866367530E-17
(PID.TID 0000.0001)   72   3   1
    -1.500000000000000E-01        -2.428612866367530E-17

-----Original Message-----
From: Chris Hill [mailto:cnh at plume.mit.edu]
Sent: Monday, October 28, 2002 10:19 AM
To: jmc at plume.mit.edu
Cc: Support at Mitgcm.Org; Sai at Gulf. Mit. Edu
Subject: help setting up tank experiement


jean-michel,

 could you spare a minute to look a problem sai is having.
 story so far is this:

 1. we are setting up a tank experiment 60cmx60cmx15cm
 2. domain is a cylindrical tank with a coffee can of ice in
    the middle.
 3. coordinate system is cartesian.
 4. we setup a depth mask "Bathy.bin"
 5. starting from global_ocean.90x40x15
    we edit SIZE.h etc... for a dx=0.005 and dz=0.01 i.e
    Nx=Ny=124,Nr=17 (couple of layers of land at the bottom!!),
    visc, kapp and deltat.
 6. we initialise theta to 20C +/- 0.001*randn().
 7. we run the model with very small deltat.
 8. it blows up.
 9. cfl for kappa, visc etc... seem ok.
10. there is a weird initial values in Ro_surf of 2.7 x 10^-17
11. maybe there is some threshold in the absolute hfac or something.
12. Ro_surf should be zero everywhere - it is in global_ocean.

 i'm kind of busy today, otherwise i could take a look.

 thanks,

chris