Regridding with GAMAP

Regridding T42 to GEOS-Chem grids

Ben Miller (bmiller@fas.harvard.edu) wrote:

Justin and I have been working on translating some emission fluxes and deposition velocity data from TOMCAT's T42 grid (128x64, with some variance in latitude step-size) into Geos 4x5 gridboxes. Do you know of any existing routines in IDL or some other language that we could adapt to make the two grids talk to each other?

Philippe Le Sager (plesager@seas.harvard.edu) replied:

There is nothing in IDL to deal with any kind of grid. However (you may have already found it) the RETRO tools (M. Schultz) can regrid data from the T42 to regular grids. It deals with NetCDF files apparently, but ascii/nc conversion is not a problem.

Have a look at the example in the regrid routine of the following package: MGS_Regrid (V2).

--Bob Y. 09:27, 8 August 2008 (EDT)

Regridding from a Lambert conformal grid to a lat-lon grid

Rynda Hudman (hudman@berkeley.edu) wrote:

I am trying to plot some North American Regional Reanalysis (NARR) data and compare it to the GEOS precipitation fields. NARR is on a Lambert Conformal grid, so it is irregular and each lat and lon have 2-dimensional arrays defining their 4 corners.

I would like to interpolate/regrid this onto a uniform grid for comparison with GEOS. Could you guys offer some suggestions?

Philippe Le Sager (plesager@seas.harvard.edu) wrote:

You need to look at the "gridding and interpolation" chapter of the IDL guide/help. You can directly go to the MIN_CURVE_SURF function though. This is the one I have mostly used. Works like a wonder.

--Bob Y. 10:32, 6 November 2008 (EST)