[ferret_users] regridding data between curvilinear grids

[Hein Zelle <hein@xxxxxxxxxxx>]

Dear Ferret users,

I am currently working with output from the WRF atmosphere model. The
model uses a Lambert projection for its computatational grid. This
means that the output fields do not have a simple longitude and
latitude axis, but instead two Ni*Nj fields are provided with longitude
and latitude values. Plotting the fields is no problem with the
curvilinear versions of shade, fill and vector:

	    fill u[k=1,l=1], xlong, xlat

works fine, except perhaps that I am now plotting a lambert projection
on a rectangular lon,lat grid, which looks funny but should be
correct.

The problem appears when I want to compare two model runs with a
different grid: one is larger than the other. Ferret doesn't know how
to regrid from the large grid to the small grid, because the axes are
defined in i and j coordinates instead of lon and lat. Is there a way
to have ferret regrid/interpolate data from one curvilinear grid to
another using the longitude and latitude fields provided with each
grid?

I can do this in matlab relatively easy, but it would be nice if my
analysis and plot scripts could remain ferret-only.

Thanks!
	Hein Zelle

--

 Unix is user friendly. It's just very particular about who 
 it's friends are.

 Hein Zelle                     hein@icce.rug.nl
	                        http://www.icce.rug.nl/~hein