Current projections of the oceanic response to anthropogenic climate forcings are uncertain. Two key sources of these uncertainties are (1) structural errors in current Earth system models and (2) imperfect knowledge of model parameters. Ocean tracer observations have the potential to reduce these uncertainties. Previous studies typically consider each tracer...
Current projections of the oceanic response to anthropogenic climate forcings are uncertain. Two key sources of these uncertainties are (1) structural errors in current Earth system models and (2) imperfect knowledge of model parameters. Ocean tracer observations have the potential to reduce these uncertainties. Previous studies typically consider each tracer...
Anthropogenically-induced increases in the acidity of the ocean have the potential to seriously harm marine calcifying organisms by decreasing the availability of carbonate (CO32−) used to make shells. I tested the effects of lowered pH on juvenile Pisaster ochraceus, an intertidal sea star and keystone predator in the eastern Pacific...
We report results from an oyster hatchery on the Oregon coast, where intake waters experienced variable carbonate chemistry (aragonite saturation state < 0.8 to > 3.2; pH < 7.6 to > 8.2) in the early summer of 2009. Both larval production and midstage growth (∼ 120 to ∼ 150 µm)...
Atmospheric carbon dioxide has increased by approximately 40% since preindustrial times from 280 ppm (parts per million) to 400 ppm. The rise in Pco₂ is causing the ocean to become more acidic due to the uptake of carbon dioxide by the water, termed “ocean acidification”. As the Pco₂ in the...
The exchange of carbon on earth is one of the fundamental processes that sustains life and regulates climate. Since the onset of the Industrial Revolution, the burning of fossil fuels and anthropogenic land conversion have altered the carbon cycle, increasing carbon dioxide in the atmosphere to levels that are unprecedented...
Freshwater systems are an important component of the global carbon cycle as they outgas disproportionately large quantities of carbon compared to the terrestrial landscape. Of particular importance are headwater streams, which represent roughly 90% of the channel network by length and have been conservatively estimated to outgas roughly 36% of...
The deglacial behavior of the sub-Arctic North Pacific is poorly constrained, with many published records suffering from limited age control due to extensive post- depositional biogenic carbonate dissolution. Potential alternative dating methods could include the correlation of stable-isotopic and/or paleomagnetic secular variation records to an independently-dated regional template, however no...
Oxygen isotope data from planktonic and benthic foraminifera, on a high-resolution age model (44 ¹⁴C dates spanning 17,400 years), document deglacial environmental change on the southeast Alaska margin (59°33.32′N, 144°9.21′W, 682 m water depth). Surface freshening (i.e., δ¹⁸O reduction of 0.8‰) began at 16,650 ± 170 cal years B.P. during...
We examined short-term (24–72 h) responses of naturally occurringmarine N2 fixing microorganisms (termed diazotrophs) to abrupt increases in the partial pressure of carbon dioxide (pCO2) in seawater during nine incubation experiments conducted between May 2010 and September 2012 at Station ALOHA (A Long-term Oligotrophic Habitat Assessment) (22°45′N, 158°W) in the...