Satellite-Derived Surface Energy Balance Estimates in the Alaskan Sub-Arctic

Abstract

Heat Capacity Mapping Mission (HCMM) data for 12 May 1978 were used in an energy balance modelto estimate evapotranspiration in sub-Arctic Alaska following snowmelt. The HCMM scene contained severalareas of melting snow as well as an actively burning fire and burn scars. Evapotranspiration was estimatedusing surface temperatures and albedos from the HCMM thermal infrared and visible channels, and fromconventional meteorological data as inputs to an energy balance model. Evapotranspiration within the areastudied was found to vary between 2 and 5 mm day, in agreement with surface measurements taken atthe same time of year in other years. Burn scars were found to evaporate at a higher rate than surroundingunburned areas (by 0.3 mm day). Areas of melting snow on the HCMM scene enabled the HCMM datato be calibrated; an offset of +5.5 K was found to be necessary. In this paper, the potential for determiningevapotranspiration over large, data-sparse areas is demonstrated. Furthermore, this study has shown theutility of the HCMM data for inferring recovery of burned areas when used with an energy balance modelto estimate the energy balance components of actively burning fires and burn scars.