Search Results - "Hamme, Roberta C"

Accurate Estimation of Net Community Production From O2/Ar Measurements by Teeter, Lianna, Hamme, Roberta C., Ianson, Debby, Bianucci, Laura

“…Under physically isolated conditions, net community production (NCP) can be accurately estimated from the rate of oxygen evasion to the atmosphere derived from…”
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Oxygen Saturation Surrounding Deep Water Formation Events in the Labrador Sea From Argo‐O2 Data by Wolf, Mitchell K., Hamme, Roberta C., Gilbert, Denis, Yashayaev, Igor, Thierry, Virginie

“…Deep water formation supplies oxygen‐rich water to the deep sea, spreading throughout the ocean by means of the global thermohaline circulation. Models suggest…”
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Volcanic ash fuels anomalous plankton bloom in subarctic northeast Pacific by Hamme, Roberta C., Webley, Peter W., Crawford, William R., Whitney, Frank A., DeGrandpre, Michael D., Emerson, Steven R., Eriksen, Charles C., Giesbrecht, Karina E., Gower, Jim F. R., Kavanaugh, Maria T., Peña, M. Angelica, Sabine, Christopher L., Batten, Sonia D., Coogan, Laurence A., Grundle, Damian S., Lockwood, Deirdre

“…Using multiple lines of evidence, we demonstrate that volcanic ash deposition in August 2008 initiated one of the largest phytoplankton blooms observed in the…”
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The solubility of neon, nitrogen and argon in distilled water and seawater by Hamme, Roberta C., Emerson, Steven R.

“…Large discrepancies in published neon and nitrogen solubility data limit the interpretation of oceanic measurements of these gases. We present new solubility…”
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Deep-sea nutrient loss inferred from the marine dissolved N2/Ar ratio by Hamme, Roberta C., Emerson, Steven R.

“…Some estimates of the budget of bioavailable nitrogen (fixed‐N) suggest that the oceanic nitrogen cycle is grossly out of balance. We use observations of…”
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Autonomous observations of biogenic N2 in the Eastern Tropical North Pacific using profiling floats equipped with gas tension devices by McNeil, Craig L., D’Asaro, Eric A., Altabet, Mark A., Hamme, Roberta C., Garcia-Robledo, Emilio

“…Oxygen Deficient Zones (ODZs) of the world’s oceans represent a relatively small fraction of the ocean by volume (<0.05% for suboxic and<5% for hypoxic) yet…”
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Temporal and spatial variability of noble gas tracers in the North Pacific by Ito, Taka, Hamme, Roberta C., Emerson, Steve

“…We develop a numerical model of dissolved argon and neon in the global ocean as a tool to investigate the physical processes controlling their saturation…”
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Early response of the northeast subarctic Pacific plankton assemblage to volcanic ash fertilization by Mélançon, Josiane, Levasseur, Maurice, Lizotte, Martine, Delmelle, Pierre, Cullen, Jay, Hamme, Roberta C., Peña, Angelica, Simpson, Kyle G., Scarratt, Michael, Tremblay, Jean-Éric, Zhou, Jie, Johnson, Keith, Sutherland, Nes, Arychuk, Michael, Nemcek, Nina, Robert, Marie

“…Fe-poor water collected at Sta. P20 in the Gulf of Alaska in June 2011 was enriched with different concentrations of volcanic ash (0.12, 1.2, and 10 mg L−1)…”
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ΔO2/N2′ as a New Tracer of Marine Net Community Production: Application and Evaluation in the Subarctic Northeast Pacific and Canadian Arctic Ocean by Izett, Robert W., Hamme, Roberta C., McNeil, Craig, Manning, Cara C. M., Bourbonnais, Annie, Tortell, Philippe D.

“…We compared field measurements of the biological O 2 saturation anomalies, ΔO 2 /Ar and ΔO 2 /N 2 , from simultaneous oceanographic deployments of a membrane…”
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Constraining ventilation during deepwater formation using deep ocean measurements of the dissolved gas ratios 40Ar/36Ar, N2/Ar, and Kr/Ar by Nicholson, David, Emerson, Steven, Caillon, Nicolas, Jouzel, Jean, Hamme, Roberta C.

“…The concentration of inert gases and their isotopes in the deep ocean are useful as tracers of air‐sea gas exchange during deepwater formation. ΔKr/Ar, ΔN2/Ar,…”
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Consistent Relationships Among Productivity Rate Methods in the NE Subarctic Pacific by Timmerman, Amanda H. V., Hamme, Roberta C.

“…Phytoplankton photosynthesize in surface waters, exporting organic carbon to depth through the biological pump. Quantifying productivity and the export of…”
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Risks of hypoxia and acidification in the high energy coastal environment near Victoria, Canada's untreated municipal sewage outfalls by Krogh, Jeremy, Ianson, Debby, Hamme, Roberta C., Lowe, Christopher J.

“…Wastewater disposal often has deleterious impacts on the receiving environment. Low dissolved oxygen levels are particularly concerning. Here, we investigate…”
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Anthropogenic and Climatic Contributions to Observed Carbon System Trends in the Northeast Pacific by Franco, Ana C., Ianson, Debby, Ross, Tetjana, Hamme, Roberta C., Monahan, Adam H., Christian, James R., Davelaar, Marty, Johnson, William K., Miller, Lisa A., Robert, Marie, Tortell, Philippe D.

“…The ocean absorbs anthropogenic carbon, slowing atmospheric CO2 increase but driving ocean acidification. Long‐term changes in the carbon system are typically…”
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Isopycnal Shoaling Causes Interannual Variability in Oxygen on Isopycnals in the Subarctic Northeast Pacific by Cervania, Ahron A., Hamme, Roberta C.

“…Over 60 years of oceanographic observations from Ocean Station Papa (OSP) in the northeast Pacific indicate faster dissolved oxygen loss than the global…”
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Using Noble Gas Measurements to Derive Air‐Sea Process Information and Predict Physical Gas Saturations by Hamme, Roberta C., Emerson, Steven R., Severinghaus, Jeffrey P., Long, Matthew C., Yashayaev, Igor

“…Dissolved gas distributions are important because they influence oceanic habitats and Earth's climate, yet competing controls by biology and physics make gas…”
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Refined Estimates of Net Community Production in the Subarctic Northeast Pacific Derived From ΔO2/Ar Measurements With N2O‐Based Corrections for Vertical Mixing by Izett, Robert W., Manning, Cara C., Hamme, Roberta C., Tortell, Philippe D.

“…We present the first field application of a N2O‐based approach to correct for vertical mixing in the estimation of net community production (NCP) from mixed…”
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Using Noble Gases to Assess the Ocean's Carbon Pumps by Hamme, Roberta C, Nicholson, David P, Jenkins, William J, Emerson, Steven R

“…Natural mechanisms in the ocean, both physical and biological, concentrate carbon in the deep ocean, resulting in lower atmospheric carbon dioxide. The signals…”
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Estimating marine carbon uptake in the northeast Pacific using a neural network approach by Duke, Patrick J, Hamme, Roberta C, Ianson, Debby, Landschützer, Peter, Ahmed, Mohamed M. M, Swart, Neil C, Covert, Paul A

“…The global ocean takes up nearly a quarter of anthropogenic CO2 emissions annually, but the variability in this uptake at regional scales remains poorly…”
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Renewal of seasonally anoxic Saanich Inlet is temporally and spatially dynamic by Soetaert, Grayson, Hamme, Roberta C., Raftery, Erinn

“…Injection of oxygenated water into anoxic basins sets off a cascade of biogeochemical reactions and ecosystem shifts. The dynamic nature of these events can…”
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Argon supersaturation indicates low decadal-scale vertical mixing in the ocean thermocline by Emerson, Steven, Ito, Taka, Hamme, Roberta C.

“…The rate of vertical mixing in the ocean's stratified waters limits the uptake of anthropogenic CO2, influences the strength of the overturning circulation,…”
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