[MITgcm-support] zero free surface

[Christopher L. Wolfe]

Nataliya,

In the rigid lid case, Eta is the pressure exerted on the surface by  
the rigid lid, not the surface elevation itself. I'm pretty sure  
there's no dynamically consistent way to fix the pressure on the  
surface to a constant in an incompressible fluid.

Perhaps something else is going wrong with the MITgcm that causes it  
to diverge from your 2D code ...

Christopher

On Apr 20, 2009, at 10:52 AM, Nataliya Stashchuk wrote:

> Hi Matt,
>
>
>
> Thank you for your answer.
>
> If I use my own 2D model to simulate internal waves, I use rigid  
> lid which is motionless.
>
> I found that with MITgcm these free surface oscillations (Eta)  
> simulate wrong solutions in 2D case for internal wave generation.
>
>
>
> Nataliya
>
>
>
> From: mitgcm-support-bounces at mitgcm.org [mailto:mitgcm-support- 
> bounces at mitgcm.org] On Behalf Of Matthew Mazloff
> Sent: 20 April 2009 18:42
> To: mitgcm-support at mitgcm.org
> Subject: Re: [MITgcm-support] zero free surface
>
>
>
> Hi Nataliya,
>
>
>
> I believe it is impossible to fix Eta to zero....a surface pressure  
> is needed to make the fluid non-divergent....perhaps you could code  
> this if you used non-hydrostatic model...not sure what would happen
>
>
>
> Anyway, you can use rigid-lid to set W = 0 at the surface....but  
> pressure will be exerted on the fluid by the lid...so in essence  
> Eta will not be 0.
>
>
>
> if you want to use rigid-lid set
>
>  rigidLid=.TRUE.,
>
> in  &PARM01 of data
>
>
>
> -Matt
>
>
>
>
>
> On Apr 20, 2009, at 10:21 AM, Nataliya Stashchuk wrote:
>
>
>
> Does anybody know how to fix Eta as zero at the free surface?
>
>
>
> Regards,
>
> Nataliya
>
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