[MITgcm-support] Vector Invariant momentum equations

[Chris Hill]

Sergio,

 It would be better to use vector invariant (VI) unless you run into
problems. 
 However, if you do run into problems with VI let us know. We do have code
for doing the cylindrical metric terms needed in flux form - but it is still
being tested and has not been checked into the CVS distribution yet.

Chris

> -----Original Message-----
> From: mitgcm-support-bounces at mitgcm.org 
> [mailto:mitgcm-support-bounces at mitgcm.org] On Behalf Of 
> adcroft at MIT.EDU
> Sent: Thursday, December 04, 2003 10:33 PM
> To: mitgcm-support at mitgcm.org; Sergio Jaramillo
> Subject: Re: [MITgcm-support] Vector Invariant momentum equations
> 
> Sergio,
> 
> In short, YES. To use the conservative form you would have to 
> code up the metric terms. The vector invariant equations are 
> more convenient to apply in arbitrary coordinates systems 
> because there's no extra metric terms to code up. However, 
> the vecinv code is not as mature as the conservative form
> (mom_fluxform) and we are still making sure that there are no 
> bugs there regards lateral boundary conditions - probably not 
> and if so not major.
> 
> Incidentally, are you reading in the cylindrical grid from 
> data files (pre-
> processed) using ini_curvilinear_grid or did you add a 
> ini_*_grid subroutine?
> 
> A.
> 
> Quoting Sergio Jaramillo <sju at eos.ubc.ca>:
> 
> > A short question. If I am using a flat polar coordinate 
> system should 
> > I use the vector invariant form of the momentum equations?, i.e., 
> > vectorInvariantMomentum =.TRUE.
> > 
> > Thanks for your help,
> > 
> > Sergio Jaramillo
> > University of British Columbia
> > 
> > mitgcm-support-request at mitgcm.org wrote:
> > 
> > >Send MITgcm-support mailing list submissions to
> > >	mitgcm-support at mitgcm.org
> > >
> > >To subscribe or unsubscribe via the World Wide Web, visit
> > >	http://dev.mitgcm.org/mailman/listinfo/mitgcm-support
> > >or, via email, send a message with subject or body 'help' to
> > >	mitgcm-support-request at mitgcm.org
> > >
> > >You can reach the person managing the list at
> > >	mitgcm-support-owner at mitgcm.org
> > >
> > >When replying, please edit your Subject line so it is more 
> specific 
> > >than "Re: Contents of MITgcm-support digest..."
> > >
> > >
> > >Today's Topics:
> > >
> > >   1. RE: [Fwd: RE: [MITgcm-support] grid-scale noise in 1/4-deg
> > >      model] (Dimitris Menemenlis)
> > >
> > >
> > 
> >---------------------------------------------------------------------
> > >-
> > >
> > >Message: 1
> > >Date: Thu, 04 Dec 2003 09:23:09 -0800
> > >From: Dimitris Menemenlis <menemenlis at jpl.nasa.gov>
> > >Subject: RE: [Fwd: RE: [MITgcm-support] grid-scale noise in 1/4-deg
> > >	model]
> > >To: mitgcm <mitgcm-support at mitgcm.org>
> > >Cc: Tong Lee <tlee at pacific.jpl.nasa.gov>,	Ichiro Fukumori
> > >	<if at pacific.jpl.nasa.gov>
> > >Message-ID: <1070558589.28269.499.camel at nireas.jpl.nasa.gov>
> > >Content-Type: text/plain; charset="us-ascii"
> > >
> > >Alistair, thanks for the tip.
> > >
> > >With COSINEMETH_III and ISOTROPIC_COS_SCALING properly set, I can 
> > >increase biharmonic friction and viscosity by a factor of 30.  
> > >Results in the attached figure compare Kuroshio and West African 
> > >coast regions for 1e10 and for 2e11 m^4/s.
> > >
> > >To do this however I have to use cosPower=4 not 
> cosPower=2.  Was that 
> > >a typo in your message yesterday?
> > >
> > >For reference, here is table of experiments.  The grid is 
> isotropic, 
> > >80S-80N, 1/4-deg grid-spacing at the Equator.  Time step is 480 s.
> > >
> > >cosPower     visca4,diffk4      result
> > >====================================
> > >2              5e10                  OK
> > >2              1e11                  bombs
> > >3              1e11                  OK
> > >3              2e11                  bombs
> > >4              3e11                  OK
> > >4              4e11                  bombs
> > >
> > >Please confirm that using cosPower=4 for an isotropic grid is OK.
> > >
> > >D.
> > >
> > >  
> > >
> > 
> > 
> > _______________________________________________
> > MITgcm-support mailing list
> > MITgcm-support at mitgcm.org
> > http://dev.mitgcm.org/mailman/listinfo/mitgcm-support
> > 
> 
> 
> 
> _______________________________________________
> MITgcm-support mailing list
> MITgcm-support at mitgcm.org
> http://dev.mitgcm.org/mailman/listinfo/mitgcm-support
>