[MITgcm-support] calculate zonal mean winds in cube-sphere grid

[David Ferreira]

Yuan Lian wrote:
> Hi David,
> 
> Thanks a lot for your help. I have one more problem needs to be solved.
> I am trying to calculate the zonal mean of UVtave data in cube-sphere. I am
> not sure how to do this since UV values are at the corners of the C-grid 
> cell.

Hi Yuan,
I think you can get outputs of UV at the center of the cells
with the package diagnostics. However, if I remember correctly
this is not enough to compute the zonal mean of UV. The best is
probably to look at a subroutine written by Andrea Molod to
compute U'V' (which maybe where you are going). It is in 
MITgcm/utils/matlab/cs_grid/calc2ndmom.m
Cheers,
david


> Thanks again for the help!
> 
> Yuan
> 
> David Ferreira wrote:
> 
>> Hi Yuan,
>> You can't use "calcZonalAvgCube.m" straight on the cube
>> u and v fields because it doesn't rotate the cube velocities
>> to the "normal" [U(West to East),V(South to North)]
>> and it assumes the input field is at the tracer points.
>> However, this is exactly what rotate_uv2uvEN.m does.
>> So first, use rotate_uv2uvEN and then you plug the outputs
>> into calcZonalAvgCube
>> david
>>
>> Yuan Lian wrote:
>>
>>> Hi,
>>>
>>> I am trying to calculate the zonal mean zonal winds and meridional winds
>>> in cube-sphere grid. The Matlab script "calcZonalAvgCube.m" can 
>>> calculate
>>> cell centered quantities. Does anyone know how to calculate the zonal
>>> mean quantities at faces of grids, ie, zonal wind "u" and meridional 
>>> wind "v"?
>>>
>>> I used to convert cube-sphere quantities to latlon grid by using 
>>> uvcube2latlon.m.
>>> I would like to know how to do this natively in cube-sphere grid.
>>>
>>> I tried to use "calcZonalAvgCube.m" with "ar"="rAw" but the zonal mean
>>> values are different from that calculated by uvcube2latlon.m (2x 
>>> smaller).
>>>
>>> Thanks for any help!
>>>
>>> Yuan
>>> _______________________________________________
>>> MITgcm-support mailing list
>>> MITgcm-support at mitgcm.org
>>> http://mitgcm.org/mailman/listinfo/mitgcm-support
>>>
>>
>>
> 
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