Ólafsdóttir
Sólveig R.
Ólafsdóttir
Sólveig R.
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ArticleUsing present-day observations to detect when anthropogenic change forces surface ocean carbonate chemistry outside preindustrial bounds(Copernicus Publications on behalf of the European Geosciences Union, 2016-09-13) Sutton, Adrienne J. ; Sabine, Chris L. ; Feely, Richard A. ; Cai, Wei-Jun ; Cronin, Meghan F. ; McPhaden, Michael J. ; Morell, Julio M. ; Newton, Jan A. ; Noh, Jae Hoon ; Ólafsdóttir, Sólveig R. ; Salisbury, Joseph E. ; Send, Uwe ; Vandemark, Douglas ; Weller, Robert A.One of the major challenges to assessing the impact of ocean acidification on marine life is detecting and interpreting long-term change in the context of natural variability. This study addresses this need through a global synthesis of monthly pH and aragonite saturation state (Ωarag) climatologies for 12 open ocean, coastal, and coral reef locations using 3-hourly moored observations of surface seawater partial pressure of CO2 and pH collected together since as early as 2010. Mooring observations suggest open ocean subtropical and subarctic sites experience present-day surface pH and Ωarag conditions outside the bounds of preindustrial variability throughout most, if not all, of the year. In general, coastal mooring sites experience more natural variability and thus, more overlap with preindustrial conditions; however, present-day Ωarag conditions surpass biologically relevant thresholds associated with ocean acidification impacts on Mytilus californianus (Ωarag < 1.8) and Crassostrea gigas (Ωarag < 2.0) larvae in the California Current Ecosystem (CCE) and Mya arenaria larvae in the Gulf of Maine (Ωarag < 1.6). At the most variable mooring locations in coastal systems of the CCE, subseasonal conditions approached Ωarag = 1. Global and regional models and data syntheses of ship-based observations tended to underestimate seasonal variability compared to mooring observations. Efforts such as this to characterize all patterns of pH and Ωarag variability and change at key locations are fundamental to assessing present-day biological impacts of ocean acidification, further improving experimental design to interrogate organism response under real-world conditions, and improving predictive models and vulnerability assessments seeking to quantify the broader impacts of ocean acidification.
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ArticleFormation and pathways of dense water in the Nordic Seas based on a regional inversion(Elsevier, 2023-02-16) Brakstad, Ailin ; Gebbie, Geoffrey ; Våge, Kjetil ; Jeansson, Emil ; Ólafsdóttir, Sólveig RósaDense waters formed in the Nordic Seas spill across gaps in the Greenland-Scotland Ridge into the abyss of the North Atlantic to feed the lower limb of the Atlantic Meridional Overturning Circulation. The overflow water transport is well known, but open questions remain regarding where and how the dense overflow waters are formed and transported to the ridge. Here we develop a regional high-resolution version of an inverse method called Total Matrix Intercomparison, which combines hydrographic and geochemical tracer observations between 2000 and 2019 to resolve the pathways that connect the overflows to their origins. Consistent with previous studies we find two main pathways feeding the Denmark Strait Overflow Water (DSOW): the East Greenland Current and the North Icelandic Jet. Most of the water supplied by the North Icelandic Jet originates in the Greenland Sea (82 ± 2%) and flows southward along an outer core of the East Greenland Current, as well as along a previously unknown pathway crossing the Jan Mayen Ridge into the Iceland Sea. In total, 39 ± 2% of the DSOW originates in the Greenland Sea, while the Iceland Sea and the Atlantic Domain of the Nordic Seas account for 20 ± 3% and 19 ± 2%, respectively. The majority of the Faroe Bank Channel Overflow Water originates in the Greenland Sea (46 ± 8%) and the Arctic Ocean (25 ± 9%). These dense waters approach the sill in the Iceland-Faroe Slope Jet and along the eastern side of the Jan Mayen Ridge. The inversion reveals unprecedented details on the upstream sources and pathways of the overflows, which have not previously been obtained using observations.•We developed an observation-based water-mass inversion for the Nordic Seas.•Most of the Denmark Strait Overflow Water originates locally in the Nordic Seas.•Greenland Sea dense water supplies the North Icelandic Jet along two distinct pathways.•The Faroe Bank Channel Overflow primarily originates in the Greenland Sea and Arctic Ocean.•It approaches the channel in the Iceland-Faroe Slope Jet and along the Jan Mayen Ridge.
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ArticleSynthesis Product for Ocean Time Series (SPOTS)—A ship-based biogeochemical pilot(Copernicus Publications, 2024-04-16) Lange, Nico ; Fiedler, Bjorn ; Alvarez, Marta ; Benoit-Cattin, Alice ; Benway, Heather M. ; Buttigieg, Pier Luigi ; Coppola, Laurent ; Currie, Kim ; Flecha, Susana ; Gerlach, Dana S. ; Honda, Makio ; Huertas, I. Emma ; Lauvset, Siv K. ; Muller-Karger, Frank ; Kortzinger, Arne ; O'Brien, Kevin M. ; Olafsdottir, Solveig R. ; Pacheco, Fernando C. ; Rueda-Roa, Digna ; Skjelvan, Ingunn ; Wakita, Masahide ; White, Angelicque E. ; Tanhua, TosteThe presented pilot for the Synthesis Product for Ocean Time Series (SPOTS) includes data from 12 fixed ship-based time-series programs. The related stations represent unique open-ocean and coastal marine environments within the Atlantic Ocean, Pacific Ocean, Mediterranean Sea, Nordic Seas, and Caribbean Sea. The focus of the pilot has been placed on biogeochemical essential ocean variables: dissolved oxygen, dissolved inorganic nutrients, inorganic carbon (pH, total alkalinity, dissolved inorganic carbon, and partial pressure of CO2), particulate matter, and dissolved organic carbon. The time series used include a variety of temporal resolutions (monthly, seasonal, or irregular), time ranges (10–36 years), and bottom depths (80–6000 m), with the oldest samples dating back to 1983 and the most recent one corresponding to 2021. Besides having been harmonized into the same format (semantics, ancillary data, units), the data were subjected to a qualitative assessment in which the applied methods were evaluated and categorized. The most recently applied methods of the time-series programs usually follow the recommendations outlined by the Bermuda Time Series Workshop report (Lorenzoni and Benway, 2013), which is used as the main reference for “method recommendations by prevalent initiatives in the field”. However, measurements of dissolved oxygen and pH, in particular, still show room for improvement. Additional data quality descriptors include precision and accuracy estimates, indicators for data variability, and offsets compared to a reference and widely recognized data product for the global ocean: the GLobal Ocean Data Analysis Project (GLODAP). Generally, these descriptors indicate a high level of continuity in measurement quality within time-series programs and a good consistency with the GLODAP data product, even though robust comparisons to the latter are limited. The data are available as (i) a merged comma-separated file that is compliant with the World Ocean Circulation Experiment (WOCE) exchange format and (ii) a format dependent on user queries via the Environmental Research Division's Data Access Program (ERDDAP) server of the Global Ocean Observing System (GOOS). The pilot increases the data utility, findability, accessibility, interoperability, and reusability following the FAIR philosophy, enhancing the readiness of biogeochemical time series. It facilitates a variety of applications that benefit from the collective value of biogeochemical time-series observations and forms the basis for a sustained time-series living data product, SPOTS, complementing relevant products for the global interior ocean carbon data (GLobal Ocean Data Analysis Project), global surface ocean carbon data (Surface Ocean CO2 Atlas; SOCAT), and global interior and surface methane and nitrous oxide data (MarinE MethanE and NiTrous Oxide product).
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ArticleGlobal variability in seawater Mg:Ca and Sr:Ca ratios in the modern ocean(National Academy of Sciences, 2020-07-17) Lebrato, Mario ; Garbe-Schonberg, Dieter ; Müller, Marius N. ; Blanco-Ameijeiras, Sonia ; Feely, Richard A. ; Lorenzoni, Laura ; Molinero, Juan-Carlos ; Bremer, Karen ; Jones, Daniel O. B. ; Iglesias-Rodriguez, M. Debora ; Greeley, Dana ; Lamare, Miles D. ; Paulmier, Aurelien ; Graco, Michelle ; Cartes, Joan ; Barcelos e Ramos, Joana ; de Lara, Ana ; Sanchez-Leal, Ricardo ; Jimenez, Paz ; Paparazzo, Flavio E. ; Hartman, Susan ; Westernströer, Ulrike ; Küter, Marie ; Benavides, Roberto ; da Silva, Armindo F. ; Bell, Steven ; Payne, Chris ; Olafsdottir, Solveig R. ; Robinson, Kelly ; Jantunen, Liisa M. ; Korablev, Alexander ; Webster, Richard J. ; Jones, Elizabeth M. ; Gilg, Olivier ; Bailly du Bois, Pascal ; Beldowski, Jacek ; Ashjian, Carin J. ; Yahia, Nejib D. ; Twining, Benjamin S. ; Chen, Xue-Gang ; Tseng, Li-Chun ; Hwang, Jiang-Shiou ; Dahms, Hans-Uwe ; Oschlies, AndreasSeawater Mg:Ca and Sr:Ca ratios are biogeochemical parameters reflecting the Earth–ocean–atmosphere dynamic exchange of elements. The ratios’ dependence on the environment and organisms' biology facilitates their application in marine sciences. Here, we present a measured single-laboratory dataset, combined with previous data, to test the assumption of limited seawater Mg:Ca and Sr:Ca variability across marine environments globally. High variability was found in open-ocean upwelling and polar regions, shelves/neritic and river-influenced areas, where seawater Mg:Ca and Sr:Ca ratios range from ∼4.40 to 6.40 mmol:mol and ∼6.95 to 9.80 mmol:mol, respectively. Open-ocean seawater Mg:Ca is semiconservative (∼4.90 to 5.30 mol:mol), while Sr:Ca is more variable and nonconservative (∼7.70 to 8.80 mmol:mol); both ratios are nonconservative in coastal seas. Further, the Ca, Mg, and Sr elemental fluxes are connected to large total alkalinity deviations from International Association for the Physical Sciences of the Oceans (IAPSO) standard values. Because there is significant modern seawater Mg:Ca and Sr:Ca ratios variability across marine environments we cannot absolutely assume that fossil archives using taxa-specific proxies reflect true global seawater chemistry but rather taxa- and process-specific ecosystem variations, reflecting regional conditions. This variability could reconcile secular seawater Mg:Ca and Sr:Ca ratio reconstructions using different taxa and techniques by assuming an error of 1 to 1.50 mol:mol, and 1 to 1.90 mmol:mol, respectively. The modern ratios’ variability is similar to the reconstructed rise over 20 Ma (Neogene Period), nurturing the question of seminonconservative behavior of Ca, Mg, and Sr over modern Earth geological history with an overlooked environmental effect.
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ArticleAutonomous seawater pCO2 and pH time series from 40 surface buoys and the emergence of anthropogenic trends(Copernicus Publications, 2019-03-26) Sutton, Adrienne J. ; Feely, Richard A. ; Maenner-Jones, Stacy ; Musielwicz, Sylvia ; Osborne, John ; Dietrich, Colin ; Monacci, Natalie ; Cross, Jessica N. ; Bott, Randy ; Kozyr, Alex ; Andersson, Andreas J. ; Bates, Nicholas R. ; Cai, Wei-Jun ; Cronin, Meghan F. ; De Carlo, Eric H. ; Hales, Burke ; Howden, Stephan D. ; Lee, Charity M. ; Manzello, Derek P. ; McPhaden, Michael J. ; Meléndez, Melissa ; Mickett, John B. ; Newton, Jan A. ; Noakes, Scott ; Noh, Jae Hoon ; Olafsdottir, Solveig R. ; Salisbury, Joseph E. ; Send, Uwe ; Trull, Thomas W. ; Vandemark, Douglas ; Weller, Robert A.Ship-based time series, some now approaching over 3 decades long, are critical climate records that have dramatically improved our ability to characterize natural and anthropogenic drivers of ocean carbon dioxide (CO2) uptake and biogeochemical processes. Advancements in autonomous marine carbon sensors and technologies over the last 2 decades have led to the expansion of observations at fixed time series sites, thereby improving the capability of characterizing sub-seasonal variability in the ocean. Here, we present a data product of 40 individual autonomous moored surface ocean pCO2 (partial pressure of CO2) time series established between 2004 and 2013, 17 also include autonomous pH measurements. These time series characterize a wide range of surface ocean carbonate conditions in different oceanic (17 sites), coastal (13 sites), and coral reef (10 sites) regimes. A time of trend emergence (ToE) methodology applied to the time series that exhibit well-constrained daily to interannual variability and an estimate of decadal variability indicates that the length of sustained observations necessary to detect statistically significant anthropogenic trends varies by marine environment. The ToE estimates for seawater pCO2 and pH range from 8 to 15 years at the open ocean sites, 16 to 41 years at the coastal sites, and 9 to 22 years at the coral reef sites. Only two open ocean pCO2 time series, Woods Hole Oceanographic Institution Hawaii Ocean Time-series Station (WHOTS) in the subtropical North Pacific and Stratus in the South Pacific gyre, have been deployed longer than the estimated trend detection time and, for these, deseasoned monthly means show estimated anthropogenic trends of 1.9±0.3 and 1.6±0.3 µatm yr−1, respectively. In the future, it is possible that updates to this product will allow for the estimation of anthropogenic trends at more sites; however, the product currently provides a valuable tool in an accessible format for evaluating climatology and natural variability of surface ocean carbonate chemistry in a variety of regions. Data are available at https://doi.org/10.7289/V5DB8043 and https://www.nodc.noaa.gov/ocads/oceans/Moorings/ndp097.html (Sutton et al., 2018).