[ecco-support] questions about interpolated WVELMASS

[Wang, Ou (329B)]

Paola,

The interpolation was done using gcmfaces’ process2interp.m
https://github.com/gaelforget/gcmfaces/blob/master/gcmfaces_IO/process2inte
rp.m.

Best,
Ou

On 2/28/19, 10:05 AM, "ecco-support-bounces at mit.edu on behalf of Paola
Cessi" <ecco-support-bounces at mit.edu on behalf of pcessi at ucsd.edu> wrote:

>Thanks Ou,
>
>I am surprised that the interpolation from LLC to lat-lon does not
>preserve incompressibility: most simple (e.g. linear) interpolation
>schemes do. Have you actually checked that the resulting flow is
>compressible?
>
>Regarding the dx, dy, since the C-grid is staggered, it is necessary to
>know where the interpolation starts in order to use the precise grid. Is
>it possible to get a copy of the interpolation code, to see how it is
>done? Then we can also check the interpolation scheme properties re:
>incompressibility.
>
>Thanks,
>
>Paola
>
>> On Feb 28, 2019, at 9:44 AM, Wang, Ou (329B) <Ou.Wang at jpl.nasa.gov>
>>wrote:
>> 
>> Hi Paola,
>> 
>> The interpolated WVELMASS is an interpolation from the LLC to the
>>lat-lon
>> grids. The interpolation does not preserve 3d incompressibility.
>> 
>> The DXC etc. for the lat-lon grid are not stored in V4¹s interpolated
>> fields. Since the lat-lon grid is a regular 0.5 degree by 0.5 degree
>>grid,
>> one can compute DXC etc. based on lat, lon, and grid resolutions.
>> 
>> Best,
>> Ou 
>> 
>> 
>> 
>> On 2/27/19, 5:15 PM, "ecco-support-bounces at mit.edu on behalf of Paola
>> Cessi" <ecco-support-bounces at mit.edu on behalf of pcessi at ucsd.edu>
>>wrote:
>> 
>>> Hi there,
>>> 
>>> I realize that E(N)VELMASS are interpoated on lat-lon grid from the LLC
>>> grid. My questions are:
>>> 
>>> 1) Is WVELMASS in the interpolated lat-lon grid recalculated from the
>>> divergence equation using E(N)VELMASS, or is it an interpolation of
>>> WVELMASS from the LLC to the lat-lon grid? And, if the latter, does the
>>> interpolation preserve 3-D incompressibility?
>>> 
>>> 2) Where are the various DX(y)G(C) (or DE(N)G(C)) for the lat-lon grid
>>> stored?
>>> 
>>> Thanks,
>>> 
>>> Paola 
>>> 
>>> ----------------------------------------------
>>> Paola Cessi   
>>> Scripps Institution of Oceanography
>>> 9500 Gilman Drive #0213
>>> La Jolla, CA 92093-0213
>>> USA            
>>> Tel: +1 858 534 0622   Fax: +1 858 534 8045
>>> e-mail: pcessi at ucsd.edu     Web:  http://www-pord.ucsd.edu/~pcessi
>>> 
>>> Delivery address (Fed-Ex, DHL, UPS, etc.):
>>> Paola Cessi
>>> University of California San Diego
>>> Keck Center - Room 366
>>> 8851 Shellback Way
>>> La Jolla, CA 92093-0213
>>> USA
>>> 
>>> 
>> 
>> 
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>