4. Regridding¶
Users that wish to interpolate their unipost output to a different grid may do so with the wgrib2 utility. The general format for re-gridding to a lat-lon grid is given in the example.
4.1. Examples of wgrib2¶
Wgrib2 is a versatile program that has the ability to convert grib2 files from one grid to another for various user-defined grids as well as pre-defined NCEP grids. Complete documentation with examples of re-gridding for all available grid definitions can be found at:
http://www.cpc.ncep.noaa.gov/products/wesley/wgrib2/new_grid.html.
Sample command line usage for calling wgrib2:
wgrib2 -new_grid_winds W -new_grid A B C outfile
Where,
W = earth or grid
earth: winds oriented to the earths north and south directions
grid: winds are rotated so that north is relative to the grid
A, B, and C represent the output grid description
Sample lat-lon grid description:
A = latlon
B = lon0:nlon:dlon
lon0 is longitude of first grid point in degrees
nlon is number of longitudes
dlon is grid resolution in degrees of longitude
C = lat0:nlat:dlat
lat0 is latitude of first grid point
nlat is number of latitudes
dlat is grid resolution in degrees of latitude
Note: wgrib2 is not distributed within the UFS weather application. Users may download and install from http://www.cpc.ncep.noaa.gov/products/wesley/wgrib2/.