12 research outputs found
Modeled Effect of Coastal Biogeochemical Processes, Climate Variability, and Ocean Acidification on Aragonite Saturation State in the Bering Sea
The Bering Sea is highly vulnerable to ocean acidification (OA) due to naturally cold, poorly buffered waters and ocean mixing processes. Harsh weather conditions within this rapidly changing, geographically remote environment have limited the quantity of carbon chemistry data, thereby hampering efforts to understand underlying spatial-temporal variability and detect long-term trends. We add carbonate chemistry to a regional biogeochemical model of the Bering Sea to explore the underlying mechanisms driving carbon dynamics over a decadal hindcast (2003–2012). The results illustrate that coastal processes generate considerable spatial variability in the biogeochemistry and vulnerability of Bering Sea shelf water to OA. Substantial seasonal biological productivity maintains high supersaturation of aragonite on the outer shelf, whereas riverine freshwater runoff loaded with allochthonous carbon decreases aragonite saturation states (ΩArag) to values below 1 on the inner shelf. Over the entire 2003–2012 model hindcast, annual surface ΩArag decreases by 0.025 – 0.04 units/year due to positive trends in the partial pressure of carbon dioxide (pCO2) in surface waters and dissolved inorganic carbon (DIC). Variability in this trend is driven by an increase in fall phytoplankton productivity and shelf carbon uptake, occurring during a transition from a relatively warm (2003–2005) to cold (2010–2012) temperature regime. Our results illustrate how local biogeochemical processes and climate variability can modify projected rates of OA within a coastal shelf system
Estimating behavior in a black box: how coastal oceanographic dynamics influence yearling Chinook salmon marine growth and migration behaviors
A science plan for carbon cycle research in North American coastal waters. Report of the Coastal CARbon Synthesis (CCARS) community workshop, August 19-21, 2014
Workshop held August 19-21, 2014, Woods Hole, MARelative to their surface area, continental margins represent some of the largest carbon
fluxes in the global ocean, but sparse and sporadic sampling in space and time makes
these systems difficult to characterize and quantify. Recognizing the importance of
continental margins to the overall North American carbon budget, terrestrial and marine
carbon cycle scientists have been collaborating on a series of synthesis, carbon budgeting,
and modeling exercises for coastal regions of North America, which include the Gulf of
Mexico, the Laurentian Great Lakes (LGL), and the coastal waters of the Atlantic,
Pacific, and Arctic Oceans. The Coastal CARbon Synthesis (CCARS) workshops and
research activities have been conducted over the past several years as a partner activity
between the Ocean Carbon and Biogeochemistry (OCB) Program and the North
American Carbon Program (NACP) to synthesize existing data and improve quantitative
assessments of the North American carbon budget.The authors of this science plan wish to acknowledge the generous support of NASA
(NNX10AU78G) and NSF (OCE-1107285) for all of the CCARS activities, including a
kickoff meeting (December 2010), a series of regional workshops (Atlantic coast, Gulf of
Mexico, Pacific coast), and the final community workshop (August 2014)
Erratum: Corrigendum: Elementary tetrahelical protein design for diverse oxidoreductase functions
Elementary tetrahelical protein design for diverse oxidoreductase functions
Emulating functions of natural enzymes in man-made constructs has proven challenging. Here we describe a man-made protein platform that reproduces many of the diverse functions of natural oxidoreductases without importing the complex and obscure interactions common to natural proteins. Our design is founded on an elementary, structurally stable 4-α-helix protein monomer with a minimalist interior malleable enough to accommodate various light- and redox-active cofactors and with an exterior tolerating extensive charge patterning for modulation of redox cofactor potentials and environmental interactions. Despite its modest size, the construct offers several independent domains for functional engineering that targets diverse natural activities, including dioxygen binding and superoxide and peroxide generation, interprotein electron transfer to natural cytochrome c and light-activated intraprotein energy transfer and charge separation approximating the core reactions of photosynthesis, cryptochrome and photolyase. The highly stable, readily expressible and biocompatible characteristics of these open-ended designs promise development of practical in vitro and in vivo applications