Land Surface Modeling with ALEXI


The Atmosphere-Land Exchange Inverse (ALEXI) model estimates surface changes of heat and water vapor at scales of 5-10 km using data derived primarily from weather satellites. The input includes surface temperature derived from GOES data, downwelling short- and long-wave radiation, and vegetation indices from high-resolution polar-orbiting satellite data (AVHRR).

Using ALEXI, surface fluxes and soil moisture content are being evaluated over several modeling regions, or domains, on a daily basis. These domains currently include the 48 contiguous United States, and two field experiment sites (IHOP and SMEX02). Potential applications for model output include regional hydrologic analyses, agricultural decision-making and yield forecasting, and assimilation into numerical weather prediction models.

In contrast to ALEXI, the DisALEXI algorithm uses high-resolution surface temperature and vegetation cover information to disaggregate (or break down) 5 km ALEXI predictions down to the 1-100 m scale for direct comparison with ground-based measurements. DisALEXI provides an indirect method of validating large-scale flux estimates.

Contact information

SSEC Public Relations
University of Wisconsin-Madison
1225 W. Dayton St.
Madison, WI 53706
Phone: (608) 263-6750
Fax: (608) 262-5974
Email contact form

Principal Investigator

Funding contributors and acknowledgements


July 14, 2005