[MITgcm-support] vertical smagorinsky viscosity

[Yangxin He]

Hi Martin,


The verification expt you mentioned did not help me much.

Instead, I went to /pkg/mom_common,

1) I am currently using viscC2smag and a quick read on mom_calc_visc.F seems to suggest only the horizontal smag is implemented but not the vertical?

2) If I use smag3d, I find mom_w_smag_3d.F, so the vertical smag is implemented if smag3d is turned on?

3) What is the recommended value for smag3d? I cannot find much info on how to use smag3d. Any chance the manual may be updated with the code?


Thanks


Yangxin

________________________________
From: MITgcm-support <mitgcm-support-bounces at mitgcm.org> on behalf of Martin Losch <Martin.Losch at awi.de>
Sent: Monday, May 13, 2019 3:59:33 AM
To: MITgcm Support
Subject: Re: [MITgcm-support] vertical smagorinsky viscosity

Hi Yangxin,

1) I think that the manual is a little behind. It’s always a good idea to check model/inc/PARAMS.h to see, what parameter are actually available, because there recent changes are more like documented that in the documentation. I find this:
C     useSmag3D      :: Use isotropic 3-D Smagorinsky
C     smag3D_coeff :: Isotropic 3-D Smagorinsky coefficient (-)
and when I grep for smag3D_coeff in the verification experiment I find this:
tutorial_deep_convection/input.smag3d
so maybe you can start there and see how it works.

2) viscosity and diffusivity are independent and viscC?Smag only affects the viscosity. Unless you set the diffusivity explicitly, it is zero.

Martin
> On 10. May 2019, at 17:39, Yangxin He <y67he at uwaterloo.ca> wrote:
>
> Hi there,
>
> 1) The manual says the vertical smag viscosity is not implemented, I wanna confirm if this is still the case? If MITgcm has the vertical smag set up now, is there a way to turn it off?
> 2) When I only use the smag harmonic viscosity, i.e. viscC2Smag, does it do anything to the diffusivity? is the diffusivity 0?
>
> thanks.
>
> Yangxin
> _______________________________________________
> MITgcm-support mailing list
> MITgcm-support at mitgcm.org
> http://mailman.mitgcm.org/mailman/listinfo/mitgcm-support

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