[MITgcm-support] How to make the viscosity and diffusivity change with temperature and pressure in MITgcm

[Martin Losch]

Hi Yanhong,

the vertical viscosities and diffusivities are routinely computed on a time step basis, if you use on of the vertical mixing schemes. Maybe starting from the simplest one, pp81, will give you an idea, how to do this for your case.

For horizontal viscosities, you could use pkg/mom_common/mom_calc_visc.F as a template of how to compute viscosities dependent on the state. For horizontal diffusivities, this is a little more difficult, I think , because there are no examples for this, also there is no code for 3D horizontal diffusivities, as far as I can see.

Matin

> On 14. Mar 2022, at 13:12, 赖燕红 <yhlai at pku.edu.cn> wrote:
> 
> Hi Martin,
> 
> 
> 
> I'm Yanhong. Recently I'm trying to simulate the magma ocean, i.e., the ocean made up of molten silicates instead of sea water using MITgcm. And I need to modify the equation of state, viscosity, and diffusivity to simulate the physical properties of molten silicates. Last time I have asked you how to modify the equation of state. And this time I want to ask that how to modify the viscosity and diffusivity scheme, and make them change with temperature and pressure at each time step in MITgcm. Because when I searched the viscosity scheme and diffusivity scheme options in MITgcm, I only found constant, vertically-dependent,initial but unchanged 3D distribution choices for viscosity, and I'm not sure how to realize temperature-pressure-dependent viscosity. Do you know how to realize this scheme? What files in MITgcm do I need to modify (such as models/src/calc_viscosity.F)? Also, what about the diffusivity scheme? Or does this kind of scheme is realizable in MITgcm? I would be very appreciate If you know how to realize this. 
> 
> 
> 
> Thank you very much in advance!
> 
> 
> 
> Best wishes,
> 
> Yanhong 
> 
> _______________________________________________
> MITgcm-support mailing list
> MITgcm-support at mitgcm.org
> http://mailman.mitgcm.org/mailman/listinfo/mitgcm-support

-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 1665 bytes
Desc: not available
URL: <http://mailman.mitgcm.org/pipermail/mitgcm-support/attachments/20220314/9c155278/attachment-0001.p7s>