The land use data sets developed at SAGE have a native resolution of 0.5 degree
in latitude x longitude. Here users can choose to interpolate their variable of
choice into any resolution, including latitude x longitude grids or Gaussian
grids (the latter are normally used by global climate models). For Gaussian
grids, we currently support only seven types (see pull down menu to the right)
- please ... contact us if you would like to see a different Gaussian grid option.
Data can be output in either ASCII format or NetCDF format. Please note that a
land-ocean mask is created "on the fly". It uses a fairly generous definition
of land (>20% land fraction) in order to include different masks used by
different groups. Please let us know if our mask generates ocean points in grid
cells where you have land.
The output ASCII file will have a header of 6 or 7 lines describing the
parameters of the output data, and the remaining lines have data written out
sequentially from west to east starting from the northwestern most grid cell,
with data in each new latitude starting a new line. The output ASCII file can
be read using the following FORTRAN program (read_ascii.f). The output of this
FORTRAN program will be a simple data table with each row containing a
longitude, latitude, and data value. If your choice is a regular latitude x
longitude grid (i.e., x resolution = y resolution), then the output ASCII file
can be directly imported into ArcGIS software.
For detailed information about the NetCDF format, go to the UCAR Unidata
Program Center (http://www.unidata.ucar.edu/packages/netcdf/).
Panoply, a free NetCDF viewing software package, is available at
[Summary provided by SAGE.]