[MITgcm-support] sea ice diagnostics

[Martin Losch]

Hi George,

all this depends a little on which solution technique you’ll use. 
“F” including stress divergence is never explicitly computed for the default “LSR” solver, but for the “EVP” solver and even for the JFNK solver (which you will probably not want to use, because it’s the most expensive one). If you want to avoid the dependence on solvers, you’ll have to recompute F before saving it (reusing code to do so).
Which solver are you using?

Martin

> On 08 Sep 2016, at 10:41, Georgy Manucharayan <gmanuch at caltech.edu> wrote:
> 
> Hi all,
> 
> I'm interested in outputting the dynamic/rheology diagnostics for the sea ice package; in particular, the force F in the ice momentum equations. As I understand one can calculate it as a divergence of stress tensor, in which case I'd like to output the stress tensor components (sigma11,sigma12,sigma22). The default outputs only its principle components (sigI, sigII) and I'm not sure if this is sufficient to calculate the force vector. Eqns. (5,6) in Hibler 1979 paper provide a recipe for calculating F based on strain rates, viscosities, and pressure; however, I would like to have an output of F exactly as it is used in the model (i.e. consistent  with the used numerical scheme).
> 
> To create the user defined diagnostic I need to know which variable names in the code denote F and sigma (and also a term -mg gradH if there is one). I guess that those might be FORCEX, FORCEY, sig1,sig2,sig12 but can someone confirm this?
> 
> Also is SIpress the same as P (pressure) in ice momentum equations?
> 
> Thanks,
> Georgy
> 
> -- 
> Georgy Manucharyan,
> Stanback Postdoctoral Scholar,
> Environmental Science and Engineering,
> California Institute of Technology,
> MS 131-24, 1200 California Blvd,
> Pasadena, CA, 91125
> 
> Office: L+R, Room 226; Tel: (626) 395-8715
> Web: http://www.its.caltech.edu/~gmanuch
> 
> 
> 
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