[ecco-support] questions about interpolated WVELMASS

[Paola Cessi]

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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