Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: February 14, 2002
Publication Date: May 31, 2002
Citation: French, A., Jacob, F., Schmugge, T., Kustas, W. 2002. TSEB vs. SEBAL: Comparison of two surface energy flux models. Eos Trans. AGU, 83(19), Spring Meet. Suppl., Abstract H51D-07, 2002 Spring Meeting, Washington DC, Published at the AGU Web Site: http://www.agu.org/meetings/waissm01.html Technical Abstract: The spatial distribution of water vapor fluxes over a landscape can be estimated by modeling the energy exchange between soil, plants and the overlying atmophere. This if feasible because the most significant energy sources, sinks and flux pathways can be quantified with a combination of ground and remote sensing observations. The mail energy source, solar radiation, is distributed into the ground, plants and air by two pathways: sensible heat transfer into the ground and air, and latent heat transfer from moist plants and soil into the air. But the questions of which observations to make, and how best to combine them, remain unresolved. The recent availability of high-resolution ASTER imagery, however, is now creating a valuable opportunity to test and experiment with surface energy flux models. ASTER has 14 bankds spanning visible through thermal infrared wavelengths with resolutions ranging from 15 m to 90 m. Our current research is very matched to the capabilities of the ASTER sensor. It is centered on a "Two-Source Energy Balance" model (2SEB), an approach that evaluates the role of soil and vegetation to convective and radiative energy exchange with the overlying atmosphere. Fractional vegetative cover and surface temperature, the primary model parameters, can be estimated using visible, near infrared and thermal infrared bands. A distinguishing characteristic of ASTER is that it detects thermal infrared over five bands, which improves the reliability of surface temperature measurements. Multiple bands also help discriminate different land cover conditions. A sequence of threee ASTER images over central Oklahoma, from September to November 2000, is used in the 2SEB model. The resulting surface flux estimates agree within 50-100 W/m^2 of ground-based flux.