2009 Annual Report 1a.Objectives (from AD-416) To determine spatially averaged evapotranspiration, as well as carbon and heat fluxes, between the plot and the regional scale (~20km) using a dedicated flux aircraft over irrigated agricultural region in the Texas High Plains (THS), to process and analyze the flux data using different aggregation techniques to enhance the utility of the data set for ALEXI/disALEXI model validation, scaling, and verification studies, and to provide additional flight activities and data collection to enhance the multi-disciplinary research occurrring during the intensive observation periods (i.e., providing boundary layer development data). 1b.Approach (from AD-416) Work with UA_AERO scientist to coordinate and execute a series of airborne flux measurement campaigns. Use the resulting large-scale flux datasets to contrain/validate ALEXI model estimates and improve embedding algorithms. 3.Progress Report The goal of this project is to work with University of Alabama (UA) scientists to coordinate and execute a series of airborne flux measurement campaigns. The resulting large-scale flux datasets will be used to constrain/validate flux estimates from the Atmosphere-Land Exchange Inverse (ALEXI) model and to improve embedded algorithms. The Bushland Evapotranspiration and Agricultural Remote Sensing Experiment, 2008 (BEAREX08) intensive field experiment was conducted during the summer months of 2008 in Bushland, Texas. Ground-based measurements of evapotranspiration (ET) were collected with eddy covariance and Bowen ratio systems and large weighing lysimeters. The collaborating scientists at UA collected airborne flux data on multiple days during BEAREX08 over the experiment site and on transects into adjacent areas, to help in upscaling point ET measurements to field and watershed scales. The aircraft flux data have been processed and are undergoing analysis in comparison with ground data and remotely sensed flux estimates. The ADODR has monitored the progress of this project through email correspondences, conference calls and periodic meetings with University of Alabama scientists. Two group experiment meetings were held in FY09.