HR: 14:40h
AN: H23H-05    [Abstracts]
TI: Investigating the use of Surface Temperature Time Series to Determine Soil Hydraulic Properties for Land Surface Models
AU: * Gutmann, E D
EM: gutmann@colorado.edu
AF: University of Colorado, Department of Geological Sciences, Campus Box 399, 2200 Colorado Ave., Boulder, CO 80309-0399 United States
AU: Small, E E
EM: Eric.Small@colorado.edu
AF: University of Colorado, Department of Geological Sciences, Campus Box 399, 2200 Colorado Ave., Boulder, CO 80309-0399 United States
AB: Soil Hydraulic Properties (SHPs) play an important role in regulating heat and moisture fluxes in land surface models. Currently SHPs are often estimated from soil texture class. However, studies have shown that this method is inadequate because there is as much variability within a texture class as there is between texture classes (Gutmann and Small 2005). Therefore, a new method of determining SHPs is required. We investigate the potential to determine SHPs from remotely sensed surface temperature (Ts). Ts is related to SHPs because soil moisture controls evaporative cooling of the surface as well as thermal conductivity and specific heat of the soil. We use the Noah and CLM land surface models to investigate the sensitivity of Ts to SHPs in semi-arid environments from central New Mexico, Kansas, and Oklahoma. To do this, we run each model with one set of SHPs. We then add random errors to the model output Ts signal and use this degraded Ts signal to determine SHPs through a model inversion. This process is repeated for each SHP in a large database of measured SHPs and the Ts derived SHPs are compared to the ``true'' SHPs. Our results indicate that, at error levels comparable to reported satellite Ts errors, we are able to determine SHPs three times better using Ts than we can from soil texture class. Finally, we look at field measurements of Ts, SHPs, and latent heat flux. We compare measured latent heat flux to modeled latent heat flux using SHPs measured in the field, SHPs derived from field Ts measurements, and SHPs derived from soil texture class.
DE: 1840 Hydrometeorology
DE: 1843 Land/atmosphere interactions (1218, 1631, 3322)
DE: 1847 Modeling
DE: 1855 Remote sensing (1640)
DE: 1865 Soils (0486)
SC: Hydrology [H]
MN: Fall Meeting 2005