2007 Annual Report 1a.Objectives (from AD-416) Work with Oklahoma University to evaluate the impacts of land cover changes, namely the agricultural harvesting of winter wheat in the Southern Great Plains, and resulting effects on water and energy exchange. Collect and process supporting flux, weather and ground-based measurements during the CLASIC field experiment, to be conducted in Oklahoma during 2007. Evaluate the effects of these changes within the ALEXI/DisALEXI surface energy balance modeling system. 1b.Approach (from AD-416) The cooperative work proposed here will assess the accuracy of ALEXI/DisALEXI-derived surface flux and moisture fields by comparing with a tower network of local weather, soil moisture and surface energy balance observations being coordinated by USDA-ARS Hydrology and Remote Sensing Laboratory and the Oklahoma Climatological Survey, a research unit of the College of Atmospheric and Geographic Sciences at the Oklahoma University. In addition, the utility of using surface flux fields and soil moisture states produced by the DisALEXI/ALEXI modeling framework for improving the initialization fields commonly used in current operational weather forecast models, known to be flawed, will be evaluated. The improvement in predictions of water vapor transport, precipitation and cloud cover will be compared against the ground and aircraft data collected during CLASIC. 3.Progress Report This report documents research conducted under a specific cooperative agreement between the ARS and the University of Oklahoma. Additional details of research can be found in the report for the parent project 1265-13610-027-00D, "Using remote sensing and modeling for evaluating hydrologic fluxes, states, and constituent transport processes within agricultural landscapes." In support of USDA-ARS CLASIC-2007 field experiment activities in central OK, scientists at the University of Oklahoma oversaw the installation and maintenance of the 4 flux tower systems in the Little Washita (LW) field site – two in winter wheat and two in rangeland/pasture. They are also maintaining two systems in the Fort Cobb site – one in wheat stubble and one in recently planted corn. In addition, they are analyzing and quality controlling data collected at LW, and collecting periodic observations of vegetation status at the flux measurement sites. Progress regarding this research is monitored by conference calls, data results, and site visits with the Principal Investigator.