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

[Yuan Lian]

Hi David,

I did use the output "UV_VEL_C' from diagnostics package. I saw the
discontinuity between tiles when I tried to use merccube to make a plot.
I will try to use calc2ndmom and see if this will center the UV data 
correctly.

Thanks a lot!

Yuan

David Ferreira wrote:
>
> 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
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>>>> MITgcm-support at mitgcm.org
>>>> http://mitgcm.org/mailman/listinfo/mitgcm-support
>>>>
>>>
>>>
>>
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>
>