CD-ROM v1.0, the FAO Local Climate Estimator
provides estimates of climatic conditions at locations for which
no observations are available. The programme is based on the 28800
stations of FAOCLIM 2.0, the global agroclimatic database maintained
by the Agrometeorology Group of FAO (see www.fao.org/sd/2001/EN1102_en.htm).
These estimates are also directly accessible for each registered
sites in TEMS (see www.fao.org/gtos/tems/tsite_list.jsp).
Next to a "no
questions asked" automatic mode, the "benchmark"
mode gives full control over the interpolation procedure (Inverse
Distance Weighting). Inputs (locations) can be entered manually
by specifying the co-ordinates or by clicking on a map; or they
can be imported from an ASCII file. Outputs are generated as ASCII
files or user-defined georeferenced grids in WinDisp format (see
also provides estimates of growing season characteristics based
on a comparison of rainfall and potential evapotranspiration (Franquin's
method). Estimates of monthly, 10-daily and daily values of common
climatic variables are given together with error estimates, using
a number of options to correct regional variability, altitude dependency
and horizontal gradients. For any given location, LocClim searches
for the nearest stations fulfiling a given criteria (absolute number,
maximum distance, altitude constraints).
If needed LocClim
fits a linear altitude function through the observations to reduce
all of them to the elevation of the desired location. This minimises
the systematic error resulting from the different elevations of
the neighbouring stations. The altitude of the desired location
can either be given by the user or taken from a built-in digital
elevation model (DEM) with a spatial resolution of 10 km and an
altitudinal resolution of 20 m (DEM downgraded from the NOAA/NCDC
Global Land One-kilometre Base Elevation).
performs a climate gradient correction by fitting a plane surface
to the observations over the latitude-longitude plane. Thus the
smooth geographical climate variation is taken into consideration.
If desired a shadowing routine can be applied that gives neighbours
hidden by closer neighbours a low weight.
For a free copy
of LocClim CD-ROM v1.0, kindly send a request to firstname.lastname@example.org,
providing your full mailing address. Please feel free to contact
the Agrometeorology Group (email@example.com)
for further information or comments on LocCLIM.
FAO :: Global Terrestrial Observing
System - GTOS :: 18