Ground-based measurements of radiative surface temperature and energy fluxes at site 26 (8739-ECB) have been used to correct aircraft measurements of radiative surface temperature made over the Institute of Hydrology (IH) site and to estimate the spatial variation of sensible and latent heat fluxes around the site. Over 80% of a 5- by 5-km area surrounding the IH site, the sensible heat flux varied between 30 and 90 W m-2 and the evaporation between 4.5 and 5.5 mm d-1. Extrapolation to site 16 (4439-ECV) gave reasonable agreement between estimated and measured sensible heat fluxes, after adjustment for the enhanced rate of transfer at site 16 caused by additional roughness and wind speed. ¿ American Geophysical Union 1992