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Full-Text Articles in Physical Sciences and Mathematics

Climate Variability, Oceanography, Bowhead Whale Distribution, And Iñupiat Subsistence Whaling Near Barrow, Alaska, Carin J. Ashjian, Stephen R. Braund, Robert G. Campbell, J. C. George, Jack Kruse, Wieslaw Maslowski, Sue E. Moore, Craig R. Nicolson, Stephen R. Okkonen, Barry F. Sherr, Evelyn B. Sherr, Yvette H. Spitz Jun 2010

Climate Variability, Oceanography, Bowhead Whale Distribution, And Iñupiat Subsistence Whaling Near Barrow, Alaska, Carin J. Ashjian, Stephen R. Braund, Robert G. Campbell, J. C. George, Jack Kruse, Wieslaw Maslowski, Sue E. Moore, Craig R. Nicolson, Stephen R. Okkonen, Barry F. Sherr, Evelyn B. Sherr, Yvette H. Spitz

Craig Nicolson

The annual migration of bowhead whales (Balaena mysticetus) past Barrow, Alaska, has provided subsistence hunting to Iñupiat for centuries. Bowheads recurrently feed on aggregations of zooplankton prey near Barrow in autumn. The mechanisms that form these aggregations, and the associations between whales and oceanography, were investigated using field sampling, retrospective analysis, and traditional knowledge interviews. Oceanographic and aerial surveys were conducted near Barrow during August and September in 2005 and 2006. Multiple water masses were observed, and close coupling between water mass type and biological characteristics was noted. Short-term variability in hydrography was associated with changes in wind speed and …


Fences Impede Long-Distance Mongolian Gazelle (Procapra Gutturosa) Movements In Drought-Stricken Landscapes, Kirk A. Olson, Thomas Mueller, Peter Leimgruber, Craig Nicolson, Todd K. Fuller, S. Bolortsetseg, Amanda E. Fine, B. Lhagvasuren, William F. Fagan Jan 2009

Fences Impede Long-Distance Mongolian Gazelle (Procapra Gutturosa) Movements In Drought-Stricken Landscapes, Kirk A. Olson, Thomas Mueller, Peter Leimgruber, Craig Nicolson, Todd K. Fuller, S. Bolortsetseg, Amanda E. Fine, B. Lhagvasuren, William F. Fagan

Craig Nicolson

Human-generated landscape barriers are especially problematic for species whose life histories entail long-distance movements. In May 2008, hundreds of Mongolian gazelles (Procapra gutturosa) became entangled in border fences as thousands attempted to move from Mongolia into Russia. Typically, the root cause of such (non-migratory) mass animal movements can only be superfi cially described. Here we draw upon satellite imagery and a fortuitously timed fi eld study to investigate a likely hypothesis. At the same time that gazelles were attempting to cross from Mongolia into Russia, gazelles equipped with satellite-linked collars repeatedly attempted to emigrate from Mongolia into China. Satellite-derived estimates …


Water Hammer Dissipation In Pneumatic Slug Tests, David Ostendorf, Don J. Degroot, Philip J. Dunaj Jan 2007

Water Hammer Dissipation In Pneumatic Slug Tests, David Ostendorf, Don J. Degroot, Philip J. Dunaj

David Ostendorf

We model and measure the dissipation of water hammer induced by well casing and water elasticity with rapid valve opening at the start of a pneumatic slug test. The higher-frequency water hammer can obscure slower, aquifer-controlled, underdamped oscillations of the rigid water column, so a quantitative description of the elastic motion improves the ability of a slug test to calibrate the aquifer permeability k. Internal friction attenuates the water hammer, subject to a known headspace pressure at the air/water interface and equilibrium pressure at the top of the well screen. An analytical elastic solution is presented and matched to an …


Adaptation And Sustainability In A Small Arctic Community: Results Of An Agent-Based Simulation Model, Matthew Berman, Craig Nicolson, Gary Kofinas, Joe Tetlichi, Stephanie Martin Dec 2004

Adaptation And Sustainability In A Small Arctic Community: Results Of An Agent-Based Simulation Model, Matthew Berman, Craig Nicolson, Gary Kofinas, Joe Tetlichi, Stephanie Martin

Craig Nicolson

Climate warming and resource development could alter key Arctic ecosystem functions that support fish and wildlife resources harvested by local indigenous communities. A different set of global forces—government policies and tourism markets—increasingly directs local cash economies that communities use to support subsistence activities. Agent-based computational models (ABMs) contribute to an integrated assessment of community sustainability by simulating how people interact with each other and adapt to changing economic and environmental conditions. Relying on research and local knowledge to provide rules and parameters for individual and collective decision making, our ABM generates hypothetical social histories as adaptations to scenario-driven changes in …


Soil Gas Transport Above A Jet Fuel/Solvent Spill At Plattsburgh Air Force Base, David Ostendorf, Alan J. Lutenegger, Shawn P. Kelley, Erich S. Hinlein Jan 2000

Soil Gas Transport Above A Jet Fuel/Solvent Spill At Plattsburgh Air Force Base, David Ostendorf, Alan J. Lutenegger, Shawn P. Kelley, Erich S. Hinlein

David Ostendorf

We calibrate a stoichiometrically coupled soil gas diffusion model with spatially resolved observations of oxygen, carbon dioxide, total hydrocarbon, and trichloroethylene vapor concentrations in the unsaturated zone above a weathered jet fuel/solvent spill at Plattsburgh Air Force Base in upstate New York. The calibration suggests that aerobic microorganisms in the capillary fringe degrade jet fuel vapor at a steady rate of 9.5 μg hydrocarbons (m−2 s−1). The solvent does not degrade in the fringe, however, and the model and data estimate a steady evaporation rate of 1.2×10−2 μg TCE (m−2 s−1). Barometric pumping slightly alters the steady concentration profile at …


A Model For Stripping Multicomponent Vapor From Unsaturated Soil With Free And Trapped Residual Nonaqueous Phase Liquid, David Ostendorf, Chiu-On Ng, Chiang C. Mei Jan 1999

A Model For Stripping Multicomponent Vapor From Unsaturated Soil With Free And Trapped Residual Nonaqueous Phase Liquid, David Ostendorf, Chiu-On Ng, Chiang C. Mei

David Ostendorf

We present a model for the multicomponent vapor transport due to air venting in an unsaturated zone in the presence of free and trapped phases of residual nonaqueous phase liquid (NAPL). On the microscale the soil particles are assumed to form spherical aggregates with micropores filled with immobile water, trapped phases of NAPL and air. The interaggregate space is occupied with mobile air, and a thin film of free NAPL adheres on the aggregate surface. While the free NAPL can readily be in equilibrium with macropore vapor, the mass transfer from immobile phases in aggregates is rate-limited by aqueous diffusion. …