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DatasetCarbonate chemistry and CTD data collected along a North Pacific transect between Hawaii and Alaska on R/V Kilo Moana cruise KM1712 in August 2017(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: firstname.lastname@example.org, 2022-02-01) Dong, Sijia ; Liu, Xuewu ; Naviaux, John D. ; Subhas, Adam V. ; Rollins, Nick E. ; Adkins, Jess F. ; Berelson, William M.This dataset includes carbonate chemistry and general measurements from CTD casts at 6 stations between Hawaii and Alaska. Data were collected in August 2017 onboard R/V Kilo Moana. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/836954
DatasetCarbonate chemistry and CTD data collected along a North Pacific transect between Hawaii and Alaska on R/V Kilo Moana cruise KM1712 in August 2017(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: email@example.com, 2021-01-20) Dong, Sijia ; Liu, Xuewu ; Naviaux, John D. ; Subhas, Adam V. ; Rollins, Nick E. ; Adkins, Jess F. ; Berelson, William M.This dataset includes carbonate chemistry and general measurements from CTD casts at 6 stations between Hawaii and Alaska. Data were collected in August 2017 onboard R/V Kilo Moana. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/836954
ArticleShallow calcium carbonate cycling in the North Pacific Ocean(American Geophysical Union, 2022-05-06) Subhas, Adam V. ; Dong, Sijia ; Naviaux, John D. ; Rollins, Nick E. ; Ziveri, Patrizia ; Gray, William R. ; Rae, James W. B. ; Liu, Xuewu ; Byrne, Robert H. ; Chen, Sang ; Moore, Christopher ; Martell-Bonet, Loraine ; Steiner, Zvi ; Antler, Gilad ; Hu, Huanting ; Lunstrum, Abby ; Hou, Yi ; Kemnitz, Nathaniel ; Stutsman, Johnny ; Pallacks, Sven ; Dugenne, Mathilde ; Quay, Paul D. ; Berelson, William M. ; Adkins, Jess F.The cycling of biologically produced calcium carbonate (CaCO3) in the ocean is a fundamental component of the global carbon cycle. Here, we present experimental determinations of in situ coccolith and foraminiferal calcite dissolution rates. We combine these rates with solid phase fluxes, dissolved tracers, and historical data to constrain the alkalinity cycle in the shallow North Pacific Ocean. The in situ dissolution rates of coccolithophores demonstrate a nonlinear dependence on saturation state. Dissolution rates of all three major calcifying groups (coccoliths, foraminifera, and aragonitic pteropods) are too slow to explain the patterns of both CaCO3 sinking flux and alkalinity regeneration in the North Pacific. Using a combination of dissolved and solid-phase tracers, we document a significant dissolution signal in seawater supersaturated for calcite. Driving CaCO3 dissolution with a combination of ambient saturation state and oxygen consumption simultaneously explains solid-phase CaCO3 flux profiles and patterns of alkalinity regeneration across the entire N. Pacific basin. We do not need to invoke the presence of carbonate phases with higher solubilities. Instead, biomineralization and metabolic processes intimately associate the acid (CO2) and the base (CaCO3) in the same particles, driving the coupled shallow remineralization of organic carbon and CaCO3. The linkage of these processes likely occurs through a combination of dissolution due to zooplankton grazing and microbial aerobic respiration within degrading particle aggregates. The coupling of these cycles acts as a major filter on the export of both organic and inorganic carbon to the deep ocean.
ArticleStorm-induced upwelling of high pCO2 waters onto the continental shelf of the western Arctic Ocean and implications for carbonate mineral saturation states(American Geophysical Union, 2012-04-11) Mathis, Jeremy T. ; Pickart, Robert S. ; Byrne, Robert H. ; McNeil, Craig L. ; Moore, G. W. K. ; Juranek, Laurie W. ; Liu, Xuewu ; Ma, Jian ; Easley, Regina A. ; Elliot, Matthew M. ; Cross, Jessica N. ; Reisdorph, Stacey C. ; Bahr, Frank B. ; Morison, James H. ; Lichendorf, Trina ; Feely, Richard A.The carbon system of the western Arctic Ocean is undergoing a rapid transition as sea ice extent and thickness decline. These processes are dynamically forcing the region, with unknown consequences for CO2 fluxes and carbonate mineral saturation states, particularly in the coastal regions where sensitive ecosystems are already under threat from multiple stressors. In October 2011, persistent wind-driven upwelling occurred in open water along the continental shelf of the Beaufort Sea in the western Arctic Ocean. During this time, cold (<−1.2°C), salty (>32.4) halocline water—supersaturated with respect to atmospheric CO2 (pCO2 > 550 μatm) and undersaturated in aragonite (Ωaragonite < 1.0) was transported onto the Beaufort shelf. A single 10-day event led to the outgassing of 0.18–0.54 Tg-C and caused aragonite undersaturations throughout the water column over the shelf. If we assume a conservative estimate of four such upwelling events each year, then the annual flux to the atmosphere would be 0.72–2.16 Tg-C, which is approximately the total annual sink of CO2 in the Beaufort Sea from primary production. Although a natural process, these upwelling events have likely been exacerbated in recent years by declining sea ice cover and changing atmospheric conditions in the region, and could have significant impacts on regional carbon budgets. As sea ice retreat continues and storms increase in frequency and intensity, further outgassing events and the expansion of waters that are undersaturated in carbonate minerals over the shelf are probable.
ArticleAuthigenic Formation of Clay Minerals in the Abyssal North Pacific(American Geophysical Union, 2022-11-02) Steiner, Zvi ; Rae, James W. B. ; Berelson, William M. ; Adkins, Jess F. ; Hou, Yi ; Dong, Sijia ; Lampronti, Giulio I. ; Liu, Xuewu ; Achterberg, Eric P. ; Subhas, Adam V. ; Turchyn, Alexandra V.Present estimates of the biogeochemical cycles of calcium, strontium, and potassium in the ocean reveal large imbalances between known input and output fluxes. Using pore fluid, incubation, and solid sediment data from North Pacific multi‐corer cores we show that, contrary to the common paradigm, the top centimeters of abyssal sediments can be an active site of authigenic precipitation of clay minerals. In this region, clay authigenesis is the dominant sink for potassium and strontium and consumes nearly all calcium released from benthic dissolution of calcium carbonates. These observations support the idea that clay authigenesis occurring over broad regions of the world ocean may be a major buffer for ocean chemistry on the time scale of the ocean overturning circulation, and key to the long‐term stability of Earth's climate.Key PointsNorth Pacific red clay sediments are a sink for marine calcium, strontium, and potassiumAuthigenic formation of clay minerals is prevalent in pelagic sediments throughout the North PacificThe main mechanism for clay formation is recrystallization of aluminosilicates, neoformation can occur in biogenic silica rich sediments