[MITgcm-support] Re: pickup problem

[chris hill]

Hi Tom,

  Have you tried the Smag scheme?
  there is an example in verification/MLAdjust/input.0.smag/data
  Baylor - what do you think?

Chris

Tom Haine wrote:
> Dear Alistair and Jean-Michel, 
> 
> I think I've found the source of the pickup problem with my version of
> the new horizontal viscosity: At pickup I removed the mean SSH from the
> SSH field (to avoid problems with very stiff barotropic modes when
> assimilating with an earlier version of this code - I should have cut
> this a while ago, but I forgot: sorry if I wasted your time, J-M.). 
> 
> Without this adjustment (i.e., the regular code) I can integrate past
> the pickup for several hundred more steps. Eventually, there's another
> divergence however:
> 
> WARNING: r*FacC < hFacInf at: i,j,bi,bj,Thid,Iter=  71  20   1   1   1
> 5977
> rStarFac,H,eta = -0.025522  5.000000E+00 -5.127608E+00
> STOP in CALC_R_STAR : too SMALL rStarFacC !
> 
> in STDERR.0032. Again, I guess this is the Leith scheme diverging
> despite the diagnostics about rStar (right?). I suppose my flow has
> become too energetic (I see more or less monotonic increase in KE prior
> to the crash). How should I control this?  Should I just increase
> viscC4Leith (currently set to 1.0)?
> 
> Thanks again for your help. I agree with Dimitris - this is a fabulous
> new scheme for the MITgcm.
> Tom.
> 
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