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Full-Text Articles in Physical Sciences and Mathematics

Forest Canopy Height From The Multiangle Imaging Spectroradiometer (Misr) Assessed With High Resolution Discrete Return Lidar, Mark Chopping, Anne Nolin, Gretchen G. Moisen, John V. Martonchik, Michael Bull May 2009

Forest Canopy Height From The Multiangle Imaging Spectroradiometer (Misr) Assessed With High Resolution Discrete Return Lidar, Mark Chopping, Anne Nolin, Gretchen G. Moisen, John V. Martonchik, Michael Bull

United States National Aeronautics and Space Administration: Publications

In this study retrievals of forest canopy height were obtained through adjustment of a simple geometricoptical (GO) model against red band surface bidirectional reflectance estimates from NASA's Multiangle Imaging SpectroRadiometer (MISR), mapped to a 250 m grid. The soil-understory background contribution was partly isolated prior to inversion using regression relationships with the isotropic, geometric, and volume scattering kernel weights of a Li-Ross kernel-driven bidirectional reflectance distribution function (BRDF) model. The height retrievals were assessed using discrete return lidar data acquired over sites in Colorado as part of the Cold Land Processes Experiment (CLPX) and used with fractional crown cover retrievals …


High Order Well-Balanced Schemes And Applications To Non-Equilibrium Flow With Stiff Source Terms, Wei Wang, Chi-Wang Shu, H. C. Yee, Björn Sjögreen Feb 2009

High Order Well-Balanced Schemes And Applications To Non-Equilibrium Flow With Stiff Source Terms, Wei Wang, Chi-Wang Shu, H. C. Yee, Björn Sjögreen

United States National Aeronautics and Space Administration: Publications

The stiffness of the source terms in modeling non-equilibrium ow problems containing finite-rate chemistry or combustion poses additional numerical difficulties beyond that for solving non-reacting flows. A well-balanced scheme, which can preserve certain non-trivial steady state solutions exactly, may help minimize some of these difficulties. In this paper, a simple one dimensional non-equilibrium model with one temperature is considered. We first describe a general strategy to design high order well-balanced finite difference schemes and then study the well-balanced properties of the high order finite difference weighted essentially non-oscillatory (WENO) scheme, modified balanced WENO schemes and various TVD schemes. The advantages …


The Nasa Land-Cover/Land-Use Change (Lcluc) Program’S Support Of The Northern Eurasia Earth Science Partnership Initiative (Neespi): Focus On Non-Boreal Europe, Garik Gutman Jan 2009

The Nasa Land-Cover/Land-Use Change (Lcluc) Program’S Support Of The Northern Eurasia Earth Science Partnership Initiative (Neespi): Focus On Non-Boreal Europe, Garik Gutman

United States National Aeronautics and Space Administration: Publications

Currently, the Northern Eurasia Earth Science Partnership Initiative (NEESPI) includes over 120 international projects involving more than 200 scientific institutions from over 30 countries. The program involves national government agencies, academia and private organizations in the U.S., Europe, Japan and Northern Eurasia (Gutman 2007). The NEESPI science is directed at evaluating the role of anthropogenic impacts on the Northern Eurasia ecosystems, the hemispheric-scale interaction and assessing how future human actions would affect the global climate and ecosystems of the region. Projections of the consequences of global changes for regional environment in Northern Eurasia are also in the center of the …