[MITgcm-support] funky ice dynamics in doubly periodic domain

[Dimitris Menemenlis]

looking at available_diagnostics.log, the following surface stress variables are available:

    79 |oceTAUX |  1 |    80 |UU      U1|N/m^2           |zonal surface wind stress, >0 increases uVel
    80 |oceTAUY |  1 |    79 |VV      U1|N/m^2           |meridional surf. wind stress, >0 increases vVel
   179 |EXFtaux |  1 |       |UM      U1|N/m^2           |zonal surface wind stress, >0 increases uVel
   180 |EXFtauy |  1 |       |VM      U1|N/m^2           |meridional surface wind stress, >0 increases vVel
   227 |SIfu    |  1 |   228 |UU      U1|N/m^2           |SEAICE zonal surface wind stress, >0 increases uVel
   228 |SIfv    |  1 |   227 |VV      U1|N/m^2           |SEAICE merid. surface wind stress, >0 increases vVel

and from seaice_diagnostics_init.F

C     pkg/diagnostics SIfu and oceTAUX, dumpfreq FU, and tavefreq FUtave
C     are identical but they differ from pkg/diagnostics EXFtaux, which
C     is stress before impact of ice.  Also when using exf bulk
C     formulae, EXFtaux is defined on tracer rather than uvel points.

C     pkg/diagnostics SIfv and oceTAUY, dumpfreq FV, and tavefreq FVtave
C     are identical but they differ from pkg/diagnostics EXFtauy, which
C     is stress before impact of ice.  Also when using exf bulk
C     formulae, EXFtauy is defined on tracer rather than vvel points.

meaning that if siAREA=1, all of the above are identical and denote stress from ice to ocean,
except that EXFtaux and EXFtauy are defined at the tracer point instead of the velocity
points on the SouthWest C-grid.

we don’t appear to have a diagnostic for air-ice stress, but that can be inferred
from 10-m wind SEAICE_drag, and SEAICE_rhoAir

since you have no shear in the surface forcing, I am assuming the internal stress will be negligible,
so if you add the components of stress at top and bottom of the ice, you should be able to estimate
expected acceleration of the sea ice, and that number should be much smaller than my 3 m/s/day
back-of-the-envelope estimate from earlier today that neglected bottom friction.

> On Feb 23, 2016, at 9:02 AM, Jean Mensa <jean.mensa at yale.edu> wrote:
> 
> ok, for oceTAUX/oceTAUY I will have to rerun but I have KE series at surface. Velocities decay with depth. Ice velocity is not anomalously large and features seem reasonable.