Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: September 16, 2003
Publication Date: December 8, 2003
Citation: Doraiswamy, P.C., Prueger, J.H., Kustas, W.P., Akhmedov, B. 2003. Defining parameters from NOAA AVHRR to map regional ET [abstract]. American Geophysical Union, December 8-12, 2003, San Francisco, CA. 2003 CDROM.
An Agrometeorological model was developed to solve the energy balance over vegetated surfaces. The magnitude of surface temperature for grass and crops is the result of the energy balance and infers to the state of its water stress. The sensible (H) and latent heat fluxes (ET) are computed using the classical equations of turbulent transfer. Soil heat flux and temperature profiles in the soil computed using the Fourier equation. Solving the energy balance equation at hourly time step, net radiation, sensible, soil, Latent heat fluxes and surface temperature were derived. Model inputs are hourly and daily climatic data and parameters that describe the properties of soil and vegetation. The objective of this research is to combine the combine the model with parameters derived from NOAA AVHRR satellite for determining the evapotranspiration in regional scale. The surface temperature obtained from satellite is used to define the model parameters at meteorological stations by comparing surface temperature obtained from model and temperature obtained from the satellite. Comparing the model predicted surface temperature with satellite surface temperature, energy balance parameters are adjusted. The model was evaluated as part of the Southern Great Plains hydrology experiment (SGP97) during July in central Oklahoma over the predominantly grassland areas. The model was calibrated with data from four ET flux station and the results scaled up to the surround areas. Results from the study show a good potential for assessment of regional ET over agricultural areas.