[ncl-talk] from staggered grid field to interpolated unique grid field

[Dennis Shea]

The Arakawa C-grid has the U, V and scalar (?T?) variables on separate
grids.

To *my* knowledge, the ESMF regrid package does not interpolate vector wind
components. Wind components should be interpolated together on the sphere.
The wind speed is conserved but the magnitudes of the wind components will
vary. For u and v on the same grid

  uNew = u*cos(rot) - v*sin(rot)    ; rot - rotation angle
  vNew = u*sin(rot) + v*cos(rot)

Actually, on the Arakawa C-grid, since u and v are on separate grids the
appropriate rotation angles would be different also.

---
What is the objective of the interpolation?

If it is 'just' graphics, then, maybe, interpolating the the V-grid and
U-grid separately to the T-grid would be acceptable.

---



On Thu, Jun 29, 2017 at 3:31 AM, Francesco Trotta <
francesco.trotta4 at unibo.it> wrote:

> Dear ncl team,
>   I using ncl and I’m producing 2 netcdf files of meridional e zonal
> velocity definite on the stagarate grid (C_arakawa U e V grids) and I need
> to pass this datasets to a collage on a unique T grid.
>
>    Is there in ncl some build-in-function which from 2 netcdf file with u
> e v defined in a staggered U e V grid produce a file with u and v field
> interpolate on T grid?
>
> thanks
> Francesco​
>
>
>
> _______________________________________________
> ncl-talk mailing list
> ncl-talk at ucar.edu
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20170630/7d4092da/attachment.html