[MITgcm-support] Diffusivities

[Thomas Zweigle]

Hi Christopher,
I have tested  a few advectionschemes
With magnitude in heat- and saltdiffusivity about 10^(-7) and 10^(-9)  
m^2/s.
The  advectionschemes (4, 7, 30, 33, 80, 81) are very similar in the  
results.
The used gridnet is 64 \times 128 Points with 1cm in horizontal and  
2cm in vertical direction.
So I get "numerical" diffusivities. You can see it in the following  
pictures

In the first picture you can see relative numerical diffusivities for  
heat and salt (relative to the advectionscheme)
And the second one you see numerical diffusivities and the  
diffusivities which should be.
You can see that the numerical diffusivity from salt is bigger as the  
intrinsic salt-diffusivity
The reason why I get tis is because the grid net is not fine enough.

So I hope this would help you, Thomas
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