Subject: sea ice concentration specification
From: Uma S. Bhatt (bhatt@iarc.uaf.edu)
Date: Thu Nov 29 2001 - 11:01:21 MST
Dear CCM users,
We were faced with the task of figuring out how to specify sea ice
concentrations and here is what we ended up doing.
We used the CSM (ice-ocean-land-atmsophere with a flux coupler) and
not the CCM3 stand alone model. Then we constructed our sea ice
concentration/sst data set file at the resolution of the ocean model
(as opposed to the atmospheric model). This file that specifies sea
ice concentration and sst is then read into both the ice model and
the ocean model. The flux coupler calculates the fluxes in the
consistent CSM manner. This was the best way for us to do this
however, depending on your goals it may be better for you to do it
differently. Since it has been over a year, I may have the details
wrong but the subroutines that read the data into the ice model were
modified to read the boundary conditions in as a netcdf file (it was
binary). We also set the ice model to run in 'sstclim' mode. So
really the only change was changing the I/O in the ice model (maybe
some small modification to the ocean model).
In the ice model documentation there is a 'formula' that tells you
how to specify sea ice concentration in terms of sst between -0.8
(0%) and -1.8 (100%).
Also, you will need to check about the horizontal temperature
gradients at the ice/ocean edge and make sure they are not extremely
strong. If you are blending an sst and ice data set there can be
strong jumps at the ice edge. This effect could dominate your model
experimental result.
Regards,
Uma Bhatt
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Uma S. Bhatt email: bhatt@iarc.uaf.edu
International Arctic Research Center
Frontier Research System for Global Change
University of Alaska, Fairbanks Room 408H IARC building
930 Koyukuk Dr.
P.O. Box 75-7335 tel: (907) 474-2662
Fairbanks, Alaska 99775-7335 fax: (907) 474-2643
http://www.frontier.iarc.uaf.edu:8080/~bhatt/
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