Surface Energy Fluxes Retrieval in the Arctic Tundra and the Boreal Forest Using a Thermal Remote Sensing Model

Abstract

The Arctic has become generally a warmer place over the past decades leading to earlier snow melt, permafrost degradation and changing plant communities. Increases in precipitation and local evaporation in the Arctic, known as the acceleration components of the hydrologic cycle, coupled with land cover changes, have resulted in significant changes in the regional surface energy budget. An extensive local evaluation of the two-source energy balance model (TSEB) - a remote sensing-based model using thermal infrared retrievals of land-surface temperature - was performed using tower measurements collected over two flux towers in Greenland’s tundra types and two flux tower sites in Alaska’s boreal forest in all sky conditions in summer. Evaluation results showed a mean turbulent flux errors generally less than 50 W•m-2 at half-hourly timesteps, similar to errors typically reported in surface energy balance modelling studies conducted in more temperate climatic regimes.