2010 Annual Report 1a.Objectives (from AD-416) 1. Evaluate how snow deposition, energy balance and melt rates vary with site conditions such as elevation, topographic structure and vegetation cover. 2. Use high resolution remote sensing of terrain and vegetation structure to improve characterization of landscape features and condition. 3. Continure testing, evaluation, validation and improvement of meterologic, hydrologic and snoe models. 4. develop a modeling strategy for extending point and catchment-scale results to larger areas and regions. 1b.Approach (from AD-416) This project will involve collaboration between ARS and University of Idaho scientists to: a. extend the surface energy balance and flux measurement efforts to evaluate growing season conditions; b. continue software testing and development for meteorological, hydrologic and snow modleing; and c. analysis of recently acquired OWLX LiDAR data, including development of specific products, and modification of simulation model structures. Documents SCA with U of ID. 3.Progress Report The assessment of sophisticated methods for measuring the loss of water to evaporation was completed, resulting in the publication of two papers, with two more submitted. This work showed how to improve the snow models by better specifying the way snow surface conditions vary over mountain watersheds. ARS scientists at the Northwest Watershed Research Center are working with university cooperators on how to use Light Detection and Ranging (LiDAR) data to produce an improved Digital Elevation Model (DEM) and an inventory of the size and distribution of different vegetation types in remote regions such as the Great Basin in the western United States. Software engineering provided by the cooperator (University of Idaho) produced an updated version of the ARS snow and climate modeling software that has now been extensively tested on Sun Solaris, Mac OS-X and Linux. This software is now in use by investigators from several campuses of the University of California, Boise State University, University of Idaho, University of Reading in the United Kingdom, University of Edinburgh in Canada, University of Saskatchewan in Canada, and the Swiss Institute of Snow and Avalanche Research in Davos. It is available to the public through the National Science Foundation’s (NSF) EpsCor program. This project has continued extensive cooperation and collaboration between the University of Idaho and ARS in Boise. Two proposals were developed with NSF through the University of Idaho (one funded and one pending). Project progress and status are reported through frequent email, regular conference calls and quarterly meetings with university cooperators. This agreement was established in support of Objective 3 of the in-house project, the goal being to develop improved coupling of surface and belowground models for spatial simulation of snowmelt, runoff, soil temperature and moisture, and streamflow.