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Full-Text Articles in Physical Sciences and Mathematics

Global Change And Eutrophication Of Coastal Waters, N. N. Rabalais, R.E. Turner, Robert J. Diaz, Dubravko Justic Aug 2009

Global Change And Eutrophication Of Coastal Waters, N. N. Rabalais, R.E. Turner, Robert J. Diaz, Dubravko Justic

VIMS Articles

The cumulative effects of global change, including climate change, increased population, and more intense industrialization and agribusiness, will likely continue and intensify the course of eutrophication in estuarine and coastal waters. As a result, the symptoms of eutrophication, such as noxious and harmful algal blooms, reduced water quality, loss of habitat and natural resources, and severity of hypoxia (oxygen depletion) and its extent in estuaries and coastal waters will increase. Global climate changes will likely result in higher water temperatures, stronger stratification, and increased inflows of freshwater and nutrients to coastal waters in many areas of the globe. Both past …


Salt Marsh Ecosystem Biogeochemical Responses To Nutrient Enrichment: A Paired N-15 Tracer Study, Dc Drake, Bj Peterson, Et Al, Le Lemay, Et Al Aug 2009

Salt Marsh Ecosystem Biogeochemical Responses To Nutrient Enrichment: A Paired N-15 Tracer Study, Dc Drake, Bj Peterson, Et Al, Le Lemay, Et Al

VIMS Articles

We compared processing and fate of dissolved NO3- in two New England salt marsh ecosystems, one receiving natural flood tide concentrations of similar to 1-4 mu mol NO3-/L and the other receiving experimentally fertilized flood tides containing similar to 70-100 mu mol NO3-/L. We conducted simultaneous (NO3-)-N-15 (isotope) tracer additions from 23 to 28 July 2005 in the reference (8.4 ha) and fertilized (12.4 ha) systems to compare N dynamics and fate. Two full tidal cycles were intensively studied during the paired tracer additions. Resulting mass balances showed that essentially 100% (0.48-0.61 mol NO3-N.ha(-1).h(-1)) of incoming NO3- was assimilated, dissimilated, …


Changes In Continental Freshwater Discharge From 1948 To 2004, Aiguo Dai, Taotao Qian, Kevin E. Trenberth, John D. Millliman May 2009

Changes In Continental Freshwater Discharge From 1948 To 2004, Aiguo Dai, Taotao Qian, Kevin E. Trenberth, John D. Millliman

VIMS Articles

A new dataset of historical monthly streamflow at the farthest downstream stations for the world’s 925 largest ocean-reaching rivers has been created for community use. Available new gauge records are added to a network of gauges that covers ∼80 × 106 km2 or ∼80% of global ocean-draining land areas and accounts for about 73% of global total runoff. For most of the large rivers, the record for 1948–2004 is fairly complete. Data gaps in the records are filled through linear regression using streamflow simulated by a land surface model [Community Land Model, version 3 (CLM3)] forced with observed …


Skill Assessment For Coupled Biological/Physical Models Of Marine Systems, Craig A. Stow, Jason Joliff, Dennis J. Mcgillicuddy Jr., Scott C. Doney, J. Icarus Allen, Marjorie A.M. Friedrichs, Kenneth A. Rose, Philip Wallhead Feb 2009

Skill Assessment For Coupled Biological/Physical Models Of Marine Systems, Craig A. Stow, Jason Joliff, Dennis J. Mcgillicuddy Jr., Scott C. Doney, J. Icarus Allen, Marjorie A.M. Friedrichs, Kenneth A. Rose, Philip Wallhead

VIMS Articles

Coupled biological/physical models of marine systems serve many purposes including the synthesis of information, hypothesis generation, and as a tool for numerical experimentation. However, marine system models are increasingly used for prediction to support high-stakes decision-making. In such applications it is imperative that a rigorous model skill assessment is conducted so that the model’s capabilities are tested and understood. Herein, we review several metrics and approaches useful to evaluate model skill. The definition of skill and the determination of the skill level necessary for a given application is context specific and no single metric is likely to reveal all aspects …


Synergistic Effects Of Iron And Temperature On Antarctic Phytoplankton And Microzooplankton Assemblages, J. M. Rose, Y. Feng, Et Al, Walker O. Smith Jr., B. Sigist, S. Tozzi, Et Al Jan 2009

Synergistic Effects Of Iron And Temperature On Antarctic Phytoplankton And Microzooplankton Assemblages, J. M. Rose, Y. Feng, Et Al, Walker O. Smith Jr., B. Sigist, S. Tozzi, Et Al

VIMS Articles

Iron availability and temperature are important limiting factors for the biota in many areas of the world ocean, and both have been predicted to change in future climate scenarios. However, the impacts of combined changes in these two key factors on microbial trophic dynamics and nutrient cycling are unknown. We examined the relative effects of iron addition (+1 nM) and increased temperature (+4 degrees C) on plankton assemblages of the Ross Sea, Antarctica, a region characterized by annual algal blooms and an active microbial community. Increased iron and temperature individually had consistently significant but relatively minor positive effects on total …