EVALUATING LATENT AND SENSIBLE HEAT FLUX DENSITIES USING EDDY COVARIANCE AND BOWEN-RATIO TECHNIQUES OVER NATIVE PASTURE RANGELAND DURING SGP 97

Authors: Prueger, John; Hatfield, Jerry; Kustas, William - Bill; HOUSER, P - NASA-GSFC; Sauer, Thomas; Starks, Patrick; Ross, John; TWINE, T - UNIV. OF WISCONSIN; NORMAN, J - UNIV. OF WISCONSIN; SCHIELDGE, J - JET PROPULSION LAB, CA

Submitted to: Trans American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: 12/11/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Reliable estimates of latent and sensible heat fluxes is an essential element of any interdisciplinary field program, such as SGP97, involving meteorology, hydrology and remote sensing. Spatial and temporal variations combined with landscape heterogeneity add to the difficulty of obtaining and interpreting surface flux data. The complexity is further compounded when efforts at regionalization of latent and sensible heat fluxes are introduced. Modeling efforts can be significantly enhanced by utilization of surface flux data to verify model results. In recent years two common methods for estimating surface flux data are eddy covariance and the Bowen-ratio. Both methods have distinct advantages and disadvantages. In this study estimates of LE and H from native pasture rangeland using eddy covariance and Bowen-ratio techniques are compared and evaluated. Data from one of the Bowen-ratio systems is from the Department of Energy's Atmospheric Radiation Measurement (ARM) Program, a network of long term flux monitoring stations located over the Great Plains region. Initial results indicate that in general estimates of LE and H from both systems tend to compare favorably. However periods do occur when there are significant discrepancies. In addition, estimates from the eddy covariance method tend to consistently underestimate LE relative to the Bowen-ratio method. Implications of these trends will be discussed and evaluated.