[MITgcm-devel] woes with exf interpolating

[Jean-Michel Campin]

Hi Matt,

Could you send also the "data.exf" you are using ? or could I find it
somewhere ?
Thanks,
Jean-Michel

On Fri, Apr 02, 2010 at 03:17:51PM -0700, Matthew Mazloff wrote:
> Hello,
>
> A problem has been found (thanks Fabien!) regarding a discontinuity in  
> the wind fields around longitude 0/360.
>
> My set-up is 1/6 of a degree and I use NCEP on a 1 degree grid and use  
> exf interpolation.  Within ~1 degree east and west of longitude 0 there 
> is a discontinuity in the wind field -- it is small but quite  
> significant in the x-derivative.  My guess is that the interpolation  
> routine is not properly accounting for periodicity -- and instead  
> perhaps incorporating zeros.
>
> Some important stuff -- I am using NCEP winds -- not stress -- and I  
> have switched to interp_method=2 instead of the hard-coded  
> interp_method=1.  This is because with interp_method 1 (linear) there  
> are discontinuities in the wind-stress curl everywhere.  With bicubic  
> interp the curl is smooth -- with this exception around longitude 0
>
> I was hoping someone with more expertise could shed light on this before 
> I go digging in the code
>
> Thanks!
> -Matt
>
>
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