Evaporation and land surface energy budget at the Salar de Atacama, northern Chile

This study uses ground-based point measurements and remote sensing techniques to assess spatial and temporal variability in evaporation and energy fluxes at the Salar de Atacama in northern Chile. Evaporation and land surface energy budget measurements were taken using eddy correlation methodologies during field campaigns in August, 2001 and January, 2002. An Advanced Spaceborne Thermal Emission and Radiation Radiometer (ASTER) image from August, 2001 was analyzed in conjunction with ground data, and three remotely sensed energy flux models were tested using surface kinetic temperature, surface reflectance and surface emissivity data products from ASTER. Results showed that net radiation and sensible heat fluxes were highest over rugged or sediment-rich salt crusts and lowest over smooth, highly reflective crusts. Basin evaporation rates were highest over ponds and wetlands along the eastern and northern salar margins. Remote sensing energy flux models faced limitations with absolute accuracy but were useful in predicting relative variations in energy budget parameters.