[MITgcm-support] Relaxation constant for salinity, tauSaltClimRelax in Global Ocean Simulation at 4deg resolution.

[Krishnakumar Rajagopalan]

Hi All,
 
I am a new user of MITgcm. Currently we are customizing the tutorial which 
models the Global Ocean Simulation at 4deg resolution to handle a 1deg 
resolution grid.
 
My question is regarding the relaxation constant for salinity in the tutorial 
(tutorial_global_oce_latlon). In the case of potential temperature, we 
calculated the tauThetaClimRelax according to the publication by Barnier et. 
al(Barnier et. al :  Thermal forcing for a global ocean circulation model using 
a three-year climatology of ECMWF analyses, Journal of Marine Systems, 1995.) 
and are getting values in the range of 60days, which is also the value chosen 
in  tutorial. 

For salinity, however, I am unable to get hold of any reference/publication 
which discusses in detail the calculation of tauSaltClimRelax. Please let me 
know how this quantity (tauSaltClimRelax) could be calculated.

Finally, I feel that the net fresh water surface flux, EmPmR, would depend 
primarily on temperature than on salinity. If true, the relaxation term in the 
salinity equation could look like,

dS/dt= (1/tauSaltClimRelax)*(theta - theta*) + flux (T*,S*)

rather than

dS/dt=(1/tauSaltClimRelax)*(S-S*) + flux(S*)

But then, I am not sure whether the salinity solution would converge to S*. And 
of course the determination of tauSaltClimRelax would still require some 
reference. 


I really appreciate your help, suggestions and comments
 
Thanks in advance
 

Regards
KrishnakumarUniversity of Hawaii at Manoa


      
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