[Fwd: RE: [MITgcm-support] grid-scale noise in 1/4-deg model]

[Alistair Adcroft]

Yes, you need 
 #define COSINEMETH_III
 #define ISOTROPIC_COS_SCALING
in either CPP_OPTIONS.h or MOM_FLUXFORM_OPTIONS.h (if you use the former you
don't need it in GAD_OPTIONS.h). Better use CPP_OPTIONS.h so it's all in one
place.

Then my guess is you can push up viscA4 to around 1.E12 which should solve
you problems.
I think 2.E12 will be beyond the edge of stability and you might find 5.E11
to be sufficient but as I said before, find the upper limit before choosing.

We will write a Smagorinsky scheme so that these issues are more easily
sorted out. Useful for the cube too.

A.
--
Dr Alistair Adcroft            http://www.mit.edu/~adcroft
MIT Climate Modeling Initiative        tel: (617) 253-5938
EAPS 54-1523,  77 Massachusetts Ave,  Cambridge,  MA,  USA

-----Original Message-----
From: mitgcm-support-bounces at mitgcm.org
[mailto:mitgcm-support-bounces at mitgcm.org] On Behalf Of Dimitris Menemenlis
Sent: Wednesday, December 03, 2003 1:18 PM
To: mitgcm
Subject: RE: [Fwd: RE: [MITgcm-support] grid-scale noise in 1/4-deg model]


>> The ones in GAD_OPTIONS.h only affect diffusivity. What about
>> CPP_OPTIONS.h or MOM_FLUXFORM_OPTIONS.h ?

Oops.  We did not set these flags in CPP_OPTIONS.h and
MOM_FLUXFORM_OPTIONS.h

Does this mean we should be able to crank up biharmonic diffusion if we set
these flags there?

>> Do you mean tests for the 1/4 degree?

Yes, are there things we can try to get rid of grid-scale noise in 1/4-deg
integration?

D.

-- 
Dimitris Menemenlis <menemenlis at jpl.nasa.gov>
Jet Propulsion Lab, California Insitute of Technology
MS 300-323, 4800 Oak Grove Dr, Pasadena CA 91109-8099
tel: 818-354-1656;  fax: 818-393-6720

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