[MITgcm-support] arbitrary tiles in cube-sphere grid

[Yuan Lian]

Hi Martin,

I thought the exch2 enables flexible configuration of tiles but I may be 
wrong. I remembered the manually generated W2_EXCH2_TOPOLOGY.h and 
w2_e2setup.F (using matlab code) had the requirement of splitting tiles 
in i-direction. The method seems to be depreciated in the new version of 
MITgcm.

Setting both nPy and nSy to 1 does get rid of the noises though. Thanks!

Best regards,
Yuan


On 3/24/12 2:34 AM, Martin Losch wrote:
> Hi Yuan,
>
> again, I am not sure about this at all, but I alway thought that with the cubed-sphere topology, you need to have all tiles in the i-direction, so neither nPy nor nSy can be larger than 1.
> It's interesting that your rhs-plot seems to work, but not the lhs (I would have guessed that both do not work because nSy=2). Let's wait for the specialists to explain this.
>
> Martin
>
> On Mar 24, 2012, at 9:27 AM, Yuan Lian wrote:
>
>> Hi Martin,
>>
>> Thanks! This is interesting. I never thought this would work when there are several subtiles in "y" direction.
>>
>> I just tried your configuration but it didn't make apparent difference. I attached a figure that compares the two setups side-by-side. The vertical velocity is shown for 1000 time steps. They "patchy" values are visible in the left panel but vanish in the right panel. The overall values look different too. The configuration in the left panel will get worse when I run the simulation longer.
>>
>> In the left panel, I used
>> PARAMETER (
>> &            sNx =   8,
>> &            sNy =   4,
>> &            OLx =   4,
>> &            OLy =   4,
>> &            nSx =   2,
>> &            nSy =   2,
>> &            nPx =  12,
>> &            nPy =   1,
>> &            Nx  = sNx*nSx*nPx,
>> &            Ny  = sNy*nSy*nPy,
>> &            Nr  =  56)
>>
>>
>> In the right panel, I used
>>
>> PARAMETER (
>> &            sNx =   8,
>> &            sNy =   8,
>> &            OLx =   4,
>> &            OLy =   4,
>> &            nSx =   1,
>> &            nSy =   2,
>> &            nPx =  12,
>> &            nPy =   1,
>> &            Nx  = sNx*nSx*nPx,
>> &            Ny  = sNy*nSy*nPy,
>> &            Nr  =  56)
>>
>>
>> Any thoughts on these? Thanks!
>>
>> Best regards,
>> Yuan
>>
>>
>>
>> On 3/24/12 12:31 AM, Martin Losch wrote:
>>> Hi Yuan,
>>>
>>> I may be wrong about this, but I think that with the cube-sphere grid you need to put all tiles "in a row", so instead of nPx=12, nPy=4, you need to have nPx=48, nPy=1
>>>
>>> I don't know anything about the Shapiro filter.
>>>
>>> Martin
>>>
>>> On Mar 24, 2012, at 6:54 AM, Yuan Lian wrote:
>>>
>>>
>>>> Hi,
>>>>
>>>> I have a question about setting arbitrary tiles in cube-sphere grid. I don't have any problems using the regular six-tile configuration. However, there are "patchy" values (more obvious in vertical or meridional velocity) near the corners of subtiles if I use the following SIZE.h
>>>>
>>>>       PARAMETER (
>>>> &            sNx =   8,
>>>> &            sNy =   4,
>>>> &            OLx =   4,
>>>> &            OLy =   4,
>>>> &            nSx =   1,
>>>> &            nSy =   1,
>>>> &            nPx =  12,
>>>> &            nPy =   4,
>>>> &            Nx  = sNx*nSx*nPx,
>>>> &            Ny  = sNy*nSy*nPy,
>>>> &            Nr  =  56)
>>>>
>>>> It appears that either EXCH2 routine or Shapiro filter does not work properly in this case.
>>>>
>>>> Does anyone also notice the problem?
>>>>
>>>> Best regards,
>>>> Yuan
>>>>
>>>>
>>>> _______________________________________________
>>>> MITgcm-support mailing list
>>>>
>>>> MITgcm-support at mitgcm.org
>>>> http://mitgcm.org/mailman/listinfo/mitgcm-support
>>> Martin Losch
>>>
>>> Martin.Losch at awi.de
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> MITgcm-support mailing list
>>>
>>> MITgcm-support at mitgcm.org
>>> http://mitgcm.org/mailman/listinfo/mitgcm-support
>> <patchy_subtiles.jpg>_______________________________________________
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> Martin Losch
> Martin.Losch at awi.de
>
>
>
>
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