Determination of the areal averaged fluxes in CLASIC: a synthesis of methodologies

Determining the relationship between eddy covariance tower measurements and the larger scale regional fluxes is important for the monitoring of land-atmosphere interactions over large heterogeneous regions. Large aperture scintillometry (LAS) has emerged as a methodology for measuring sensible heat fluxes directly at the large scale, which can potentially be used for verification of satellite derived flux estimates. The CLASIC campaign in Oklahoma during June, 2007 provided an excellent opportunity to compare the LAS and tower observations. Fluxes derived from a tethersonde system provide an additional independent estimation of the regional scale fluxes. MODIS imagery and a Soil-Vegetation-Atmosphere-Transfer (SVAT) model are used to determine the spatially variable fluxes over the entire Fort Cobb intensive study area. Here, we examine the scaling relationships from tower to satellite pixel and relate these formulations to soil moisture conditions. As towers become the standard measurement system for quantifying the exchange of energy and mass fluxes between the surface and the atmosphere, it is vitally important to understand the scaling relationships for monitoring the large scale variability in water, carbon and energy cycling with remote sensing.