HR: 10:20h
AN: H41H-01 INVITED     [PDF]
TI: Large Eddy Simulation over Heterogeneous Terrain with Remotely Sensed Land Surface Conditions
AU: * Albertson, J D
EM: john.albertson@duke.edu
AF: Duke University, Department of Civil and Environmental Engineering, Durham, NC 27708 United States
AU: Kustas, W P
EM: bkustas@hydrolab.arsusda.gov
AF: USDA-ARS-Hydrology and Remote Sensing Lab, Bldg. 007, BARC-WEST, Rm. 104, Beltsville, MD 20705 United States
AB: A framework is developed to explore the coupling between the land and the atmospheric boundary layer using three dimensional turbulence simulation over remotely sensed land surface images. The coupled set of equations is integrated with boundary conditions from day 221 of the Monsoon90 experiment and analysis is conducted to quantify the transmission of surface heterogeneity information into the ABL. The LES model incorporates: radiant energy availability; spatial fields of remotely observed surface cover, temperature, and moisture; and, the ability to account for the separate contributions of soil and vegetation (i.e. two sources) to the mass and energy exchanges. Analysis of the results reveals: (i) that the combination of remotely sensed data and LES (in the absence of free parameters) yields regionally averaged land surface fluxes and ranges of spatial variability in the fluxes that compare well to similar measures from a network of flux measuring stations, (ii) that the correlation between time averaged surface and air temperatures is dependent on the length scale of the surface features, (iii) that the horizontal standard deviation of mean air temperature decreased logarithmically with height in the atmospheric surface layer; and (iv) that the mean air temperature contains spatial variability induced preferentially from variations in surface temperature occurring at scales greater than 500-1000 m. Hence, the feedback strength between the land and the atmosphere is shown to be scale-dependent for the range of length scales (i.e. $<$ 10km) studied here.
DE: 0315 Biosphere/atmosphere interactions
DE: 1818 Evapotranspiration
DE: 1833 Hydroclimatology
SC: Hydrology [H]
MN: 2003 Fall Meeting