|French, Andrew - NASA GSFC|
|Jacob, Frederic - ECOLE SUPERIEURE|
Submitted to: International Union of Geodesy and Geophysics Meeting
Publication Type: Abstract Only
Publication Acceptance Date: March 29, 2003
Publication Date: N/A
Technical Abstract: Knowledge of the relationship between the accuracy of surface energy balance estimates and remote sensing resolution is important for the integration of instantaneous satellite observations with regional and global scale hydrological models. Higher resolution thermal infrared (TIR) imagery, such as the 90 m data from the Advanced Spaceborne Thermal Emission and Reflection (ASTER) radiometer on NASA's Terra satellite, provide the needed observations to distinguish between hydrological end-member conditions and are expected to be more accurate than imagery with resolutions >1 km. But higher resolution observations are instantaneous and usually not repeatable at time intervals less than 2 to 4 weeks. On the other hand, lower resolution TIR imagery from sensors such as those on the geostationary GOES satellite, in combination with hydrological assimilation models, can estimate the diurnal variations in surface energy balance. To assess the relative merits of resolution vs. imaging frequency, we have collected a series of 10 ASTER observations, between May and November 2002 over the arid Jornada Experimental Range in New Mexico, and modeled the surface energy balance. Estimates of the energy components are made from the original resolution (90 m) up to an aggregated resolution of 4 km. These estimates are compared with ground based flux observations, and then compared with each other. Loss in range of data and expected biases due to resolution effects will be discussed.