[MITgcm-devel] r* changes 3 weeks ago?

[Thomas Haine]

Hi Alistair, J-M, 

I guess that the buggy z* code was less sensitive to bathymetry. With a
new bathy and the bug-fix in place I have a stable code with the same
timestep as before. I suspect the main bathy fix was to exclude all
ocean cells shallower than 20m. I also removed all surface ocean cells
with 3 sides of land.

Tom.

On Mon, 2005-08-08 at 19:58 -0400, Jean-Michel Campin wrote:
> Hi Alistair,
> 
> I've just re-run the global_ocean.cs without realFreshWater,
> and get almost zero (~truncation error) for W @ the surface
> (in fact, it's w*), both with the bug in calc_r_star and without:
> 
> with the bug:
>  k | --  Average --  | --  Std.Dev  -- | --     min  --  | --     max   -- |
>   1 -1.5241674088E-24  1.2856393143E-21 -7.1272208023E-21  3.4752623419E-20
>   2  2.5044944587E-10  3.0654052890E-06 -1.7805864466E-05  3.2450027450E-05
> 
> and without:
>  k | --  Average --  | --  Std.Dev  -- | --     min  --  | --     max   -- |
>   1 -1.8486143344E-23  1.0848723067E-21 -2.0861288253E-20  1.2560737602E-20
>   2  2.6798489476E-10  3.0654806148E-06 -1.7807405140E-05  3.2452863292E-05
> 
> My impression is that without OBCS, the z* seems to work.
> 
> Jean-Michel
> 
> On Thu, Jul 14, 2005 at 02:34:31PM -0400, Alistair Adcroft wrote:
> > JMC changed calc_r_star.F 3 weeks ago (June 19) with a "bug fix" and 
> > reading the code it certainly looks like a treu bug fix.
> > 
> > http://mitgcm.org/cgi-bin/viewcvs.cgi/MITgcm/model/src/calc_r_star.F.diff?r1=1.4&r2=1.5
> > 
> > However, the Irminger Sea calculation (Tom Haine) is no longer stable 
> > using z* where it was before the bug fix. What's up?
> > 
> > How can we have produced the figures for the z* paper if this bug was 
> > turning off z* over the slope region?
> > 
> > Puzzled.
> > 
> > A. + T.
> > -- 
> > Dr Alistair Adcroft            http://www.mit.edu/~adcroft
> > MIT Climate Modeling Initiative        tel: (617) 253-5938
> > EAPS 54-1624,  77 Massachusetts Ave,  Cambridge,  MA,  USA
> > _______________________________________________
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> > MITgcm-devel at mitgcm.org
> > http://mitgcm.org/mailman/listinfo/mitgcm-devel
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-- 
--------------------------------------------
 Thomas W. N. Haine
                                                                                                                                                              
 Associate Professor of Physical Oceanography,
 Department of Earth & Planetary Sciences,
 329 Olin Hall, The Johns Hopkins University,
 Baltimore, MD 21218, USA.
 Tel : 410 516 7048,   Fax : 410 516 7933
 Thomas.Haine at jhu.edu
 http://www.jhu.edu/~eps/faculty/haine
--------------------------------------------