Article
Environmental Sciences
Wenhao Wang, Heather Goring-Harford, Korinna Kunde, E. Malcolm S. Woodward, Maeve C. Lohan, Douglas P. Connelly, Rachael H. James
Summary: Chromium isotopic composition in ancient marine sediments can be used to infer changes in past seawater oxygenation or biological productivity. The relative contribution of external sources and internal cycling on the distribution of dissolved chromium in the oceans is still debated. In this study, water column profiles were obtained for dissolved chromium concentrations and chromium isotopes in the sub-tropical North Atlantic. The results suggest that benthic inputs and the formation of colloid aggregates of Fe-(oxyhydr)oxides play important roles in shaping the distribution of chromium.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Geosciences, Multidisciplinary
Frerk Poppelmeier, Marcus Gutjahr, Patrick Blaser, Hartmut Schulz, Finn Suefke, Joerg Lippold
Summary: Research has shown that deep ocean carbon storage increased with limited variations in the past 100,000 years, with northern-sourced water dominating throughout. During Marine Isotope Stage 4, proportions of northern-sourced water even increased by approximately 15% in the Equatorial and Northeast Atlantic, questioning the idea that cold climates promote the expansion of southern-sourced water.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Engineering, Environmental
Daniele de A. Miranda, Juliana Leonel, Jonathan P. Benskin, Jana Johansson, Vanessa Hatje
Summary: The study found that the distribution of PFAS in the Western Tropical Atlantic Ocean varied with depth and longitude sectors. PFAS mainly existed in the form of perfluoroalkyl carboxylic acids, and the origin of different water masses was also an important factor affecting PFAS concentrations and profiles.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Oceanography
Laura M. Whitmore, Alan M. Shiller, Tristan J. Horner, Yang Xiang, Maureen E. Auro, Dorothea Bauch, Frank Dehairs, Phoebe J. Lam, Jingxuan Li, Maria T. Maldonado, Chantal Mears, Robert Newton, Angelica Pasqualini, Helene Planquette, Robert Rember, Helmuth Thomas
Summary: This study investigates the distribution of barium (Ba) in the Arctic Ocean and finds that margins are a substantial source of Ba to the water column. Nonconservative inputs account for about 50% of the Ba inventory in the upper 500 m of the Arctic water column. The study also identifies the mixing of Arctic Ocean-derived waters and Baffin Bay-derived waters in the Canadian Arctic Archipelago.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Review
Geosciences, Multidisciplinary
Bochao Xu, Sanzhong Li, William C. Burnett, Shibin Zhao, Isaac R. Santos, Ergang Lian, Xianyao Chen, Zhigang Yu
Summary: Naturally occurring radium isotopes, especially Ra-226, can serve as powerful tracers in marine processes. By synthesizing historical data from various research programs, a global distribution of Ra-226 in the ocean has been constructed. The distribution patterns of Ra-226 are closely related to the circulation pathways of deep water masses, such as the Antarctic Bottom Water and North Atlantic Deep Water. The combination of Ra-226 with other natural tracers provides valuable insights into water mixing and source/sink behaviors of elements.
EARTH-SCIENCE REVIEWS
(2022)
Article
Environmental Sciences
Shaily Rahman, Alan M. Shiller, Robert F. Anderson, Matthew A. Charette, Christopher T. Hayes, Melissa Gilbert, Karen R. Grissom, Phoebe J. Lam, Daniel C. Ohnemus, Frank J. Pavia, Benjamin S. Twining, Sebastian M. Vivancos
Summary: Processes controlling dissolved barium concentrations were investigated along two transects in the North Atlantic and Eastern Tropical Pacific. Conservative mixing and nonconservative processes were found to contribute to the variability of dissolved barium. Particulate excess barium formation and dissolution rates showed subsurface maxima, and the burial efficiency of particulate excess barium did not seem to depend on barite saturation indices. Revising river and shelf barium inputs may help balance the marine barium isotope budget.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Article
Oceanography
N. Lehmann, M. Kienast, J. Granger, J. -E. Tremblay
Summary: The Canadian Arctic Archipelago plays a crucial role in nutrient flow from the North Pacific to the North Atlantic. However, there is limited understanding of nutrient transport and cycling in this region. This study investigates the nitrogen and oxygen isotope ratios of nitrate in the Canadian Arctic Archipelago, providing insights into nutrient dynamics. The results show enhanced nitrate assimilation in the eastern part of the archipelago, characterized by high nitrate isotope values. Additionally, it reveals that a substantial fraction of nutrients in the central archipelago comes from the Atlantic, a larger proportion than previously estimated. Benthic denitrification has little influence on nutrient properties in this area.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Geochemistry & Geophysics
Ruixue Wang, Josephine A. Clegg, Peter M. Scott, Christina S. Larkin, Feifei Deng, Alexander L. Thomas, Xin-Yuan Zheng, Alexander M. Piotrowski
Summary: Despite decades of research, significant gaps in our understanding of the oceanic cycling of neodymium (Nd) and rare earth elements (REEs) remain. Observations show that dissolved Nd concentration typically increases with depth, while Nd isotopes reflect conservative water mass mixing in the intermediate and deep ocean, known as the Nd paradox. This study in the South Atlantic provides detailed insights into the spatial controls on ocean geochemistry and the processes influencing Nd isotopic compositions.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Meteorology & Atmospheric Sciences
D. S. Dukhovskoy, I. Yashayaev, E. P. Chassignet, P. G. Myers, G. Platov, A. Proshutinsky
Summary: The impact of increasing Greenland freshwater discharge on the subpolar North Atlantic requires decades to adjust, with long-lasting freshwater discharge leading to a non-steady-state response in the region.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Oliver J. Tooth, Helen L. Johnson, Chris Wilson
Summary: The strength of the AMOC at subpolar latitudes is dominated by water mass transformation in the eastern SPNA. However, the distribution of this overturning across the individual circulation pathways of both the SPG and the Nordic seas overflows is poorly understood. Water mass transformation along the pathways of the eastern SPG accounts for 55% of the mean strength of the eastern subpolar AMOC.
JOURNAL OF CLIMATE
(2023)
Article
Geochemistry & Geophysics
Yingzhe Wu, Leopoldo D. Pena, Robert F. Anderson, Alison E. Hartman, Louise L. Bolge, Chandranath Basak, Joohee Kim, Micha J. A. Rijkenberg, Hein J. W. De Baar, Steven L. Goldstein
Summary: The global overturning ocean circulation is crucial for global climate and can be traced using neodymium (Nd) isotopes. However, the value of Nd isotopes as a circulation tracer has been questioned due to various processes that can modify seawater Nd isotope ratios. This study investigates the integrity of Nd isotopes as an ocean circulation tracer in the Southwest Atlantic and confirms their potential for reconstructing past ocean circulation changes.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Multidisciplinary Sciences
Nathan T. Lanning, Shuo Jiang, Vinicius J. Amaral, Katherine Mateos, Janelle M. Steffen, Phoebe J. Lam, Edward A. Boyle, Jessica N. Fitzsimmons
Summary: Reversible scavenging is the process by which dissolved metals exchange onto and off sinking particles and are transported to deeper depths. This process deepens the distribution of adsorptive elements and shortens their residence times in the ocean. Understanding which metals undergo reversible scavenging and under what conditions is important.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Meteorology & Atmospheric Sciences
Helene Asbjornsen, Helen L. Johnson, Marius Arthun
Summary: The study shows that the inflow across the Iceland-Scotland Ridge impacts the heat supply to the Nordic seas from the subpolar North Atlantic and influences marine ecosystems and sea ice extent further north. The inflow primarily originates from the subtropics and the Arctic, with its properties and volume transport being affected by atmospheric circulation anomalies and shifts in ocean currents. Gyre dynamics and wind forcing play a crucial role in determining the inflow properties and volume transport in the Nordic seas.
JOURNAL OF CLIMATE
(2021)
Review
Geochemistry & Geophysics
Jessica N. Fitzsimmons, Tim M. Conway
Summary: The micronutrient iron is crucial in determining the primary production in the global ocean. Understanding the sources, sinks, and internal cycling processes of iron is essential to comprehend its role in the global carbon cycle and climate change. Iron isotopic analysis in seawater has proved to be an effective tool in identifying iron sources and studying biogeochemical processes. This review provides a summary of the different iron source fluxes and their isotopic signatures, as well as the potential of iron isotopes in studying internal oceanic cycling of iron.
ANNUAL REVIEW OF MARINE SCIENCE
(2023)
Article
Meteorology & Atmospheric Sciences
David B. Bonan, Andrew F. Thompson, Emily R. Newsom, Shantong Sun, Maria Rugenstein
Summary: This study examines the response of the Atlantic meridional overturning circulation (AMOC) to an abrupt quadrupling of atmospheric carbon dioxide using a collection of GCM simulations. The simulations show consistent weakening of the AMOC during the first century, but diverse behaviors over longer time scales. The study attributes the AMOC behavior to changes in temperature and salinity in different regions, highlighting the importance of considering high-latitude freshwater changes and salinity anomalies for understanding the long-term evolution of the AMOC.
JOURNAL OF CLIMATE
(2022)
Article
Environmental Sciences
Holly Wallington, Katharine Hendry, Rupert Perkins, Marian Yallop, Sandra Arndt
Summary: Riverine dissolved silicon (DSi) and biogenic silica (BSi) in estuaries are influenced by various biotic and abiotic processes. The benthic diatom-dominated biofilm system plays a crucial role in controlling silicon transport in alluvial estuaries. The Severn Estuary in the UK was studied to enhance our understanding of silicon transport in benthic-dominated systems. The study found that river and tidal hydrodynamics drove changes in DSi concentrations, and that benthic biofilms on intertidal mudflats contributed to high BSi content in the estuary.
Article
Environmental Sciences
Ruth L. Airs, Rachael Beale, Luca Polimene, Yin Chen, Michaela A. Mausz, David J. Scanlan, Claire E. Widdicombe, Glen A. Tarran, E. Malcolm S. Woodward, Carolyn Harris, Andrea McEvoy
Summary: Glycine betaine (GBT) is a nitrogenous osmolyte found throughout the marine environment. This study presents a seasonal dataset of GBT concentrations in marine suspended particulate material, showing peaks in summer and autumn. The GBT concentrations are associated with specific phytoplankton groups or species, suggesting different environmental drivers for different periods of the GBT seasonality.
Correction
Environmental Sciences
Ruth L. Airs, Rachael Beale, Luca Polimene, Yin Chen, Michaela A. Mausz, David J. Scanlan, Claire E. Widdicombe, Glen A. Tarran, E. Malcolm S. Woodward, Carolyn Harris, Andrea McEvoy
Article
Geochemistry & Geophysics
James Kershaw, Joseph A. Stewart, Ivo Strawson, Maria Luiza de Carvalho Ferreira, Laura F. Robinson, Katharine R. Hendry, Ana Samperiz, Andrea Burke, James W. B. Rae, Rusty D. Day, Peter J. Etnoyer, Branwen Williams, Vreni Haussermann
Summary: Based on the study of modern Stylasteridae corals, it is found that [Ba]SW and sample mineralogy are the main factors influencing coral Ba/Ca ratios, while seawater temperature has a weak influence. Paired Sr/Ca measurements suggest that the variability in scleractinian Ba/Ca may be related to varying degrees of Rayleigh fractionation during calcification. Stylasteridae corals have the potential to be an important new archive for paleoceanographic studies.
Article
Environmental Sciences
Johan C. Faust, Philippa Ascough, Robert G. Hilton, Mark A. Stevenson, Katharine R. Hendry, Christian Maerz
Summary: The association of organic carbon with iron minerals (Fe-R) is crucial for its long-term storage and burial efficiency in marine sediments. However, uncertainties exist regarding the sources, age, lability, and composition of this organic matter. This study uses radiocarbon and stable isotopes to investigate the source and age of Fe-R-associated organic carbon in Arctic marine sediments. The results suggest that fresh and marine organic matter rapidly binds with Fe-R, protecting and stabilizing labile organic matter and highlighting the potential of the organic carbon-iron association as an efficient carbon burial mechanism.
ENVIRONMENTAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
J. T. Middleton, W. -l. Hong, A. Paytan, M. E. Auro, E. M. Griffith, T. J. Horner
Summary: The barium isotope composition of sedimentary barite is a powerful tool for studying the sources and cycling of barium in marine environments. Ion exchange, particularly in mineral-fluid systems, plays an important role in the fractionation of Ba isotopes in BaSO4. The experiments conducted under marine-relevant conditions reveal the rate and isotopic effect associated with ion exchange in BaSO4-fluid systems.
Article
Geochemistry & Geophysics
J. T. Middleton, A. Paytan, M. Auro, M. A. Saito, T. J. Horner
Summary: The isotope composition of barium (Ba) in barite (BaSO4) is a powerful tool for tracing the cycles of pelagic Ba, carbon, and sulfur. This study analyzed the Ba isotope composition of porewaters and co-located BaSO4 in sediments from the Equatorial Pacific, and conducted laboratory experiments to assess the rates of Ba isotope alteration. The results suggest that ion exchange occurs in Equatorial Pacific sediments, and this process drives the observed Ba isotope offsets between pelagic BaSO4 and porewaters.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
Chadlin M. Ostrander, Sune G. Nielsen, Hayley J. Gadol, Luciana Villarroel, Scott D. Wankel, Tristan J. Horner, Jerzy Blusztajn, Colleen M. Hansel
Summary: Thallium (Tl) isotopes serve as a valuable tool for studying the history of molecular oxygen in seawater. Understanding the modern Tl isotope cycle is crucial for its application, especially in anoxic environments. This study found significant variability in Tl isotopes in short timeframes and observed the association of Tl with sulfide and other metals. The sediment data revealed limited isotopic variability, indicating the ability of sediments to capture the Tl isotope composition of contemporary waters.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Chemistry, Multidisciplinary
Rhiannon L. Jones, Michael P. Meredith, Maeve C. Lohan, E. Malcolm S. Woodward, Katrien Van Landeghem, Kate Retallick, Oliver Flanagan, Mehul Vora, Amber L. Annett
Summary: Continued atmospheric and oceanic warming at the West Antarctic Peninsula (WAP) is causing significant changes to glaciers and the marine environment. Two bays along the WAP were compared during austral summer 2020 to study sediment sources and drivers of macronutrient distributions. The study found that land-terminating glaciers have a meltwater-rich surface layer with strong vertical mixing, while marine-terminating glaciers drive vigorous mixing of sediment and entrainment of macronutrient deep waters. This shift to land-terminating glaciers may have a significant impact on nutrient and sediment supply to the euphotic zone, affecting primary productivity and carbon uptake efficiency.
Article
Chemistry, Multidisciplinary
Xue-Gang Chen, Dagmara Rusiecka, Martha Gledhill, Angela Milne, Amber L. Annett, Antony J. Birchill, Maeve C. Lohan, Simon Ussher, E. Malcolm S. Woodward, Eric P. Achterberg
Summary: This article reports on the seasonal distributions of dissolved zinc, nickel, copper, cadmium, aluminum, and nutrients on the Northeast Atlantic continental margin. The variations in surface water trace metals and nutrient concentrations were mainly regulated by seasonal changes in biological processes. The stoichiometry of trace metals and nutrients on the continental shelf was additionally affected by fluvial inputs.
Correction
Chemistry, Medicinal
Catherine R. Back, Henry L. Stennett, Sam E. Williams, Luoyi Wang, Jorge Ojeda Gomez, Omar M. Abdulle, Thomas Duffy, Christopher Neal, Judith Mantell, Mark A. Jepson, Katharine R. Hendry, David Powell, James E. M. Stach, Angela E. Essex-Lopresti, Christine L. Willis, Paul Curnow, Paul R. Race
Article
Environmental Sciences
E. Elena Garcia-Martin, Richard Sanders, Chris D. Evans, Vassilis Kitidis, Dan J. Lapworth, Bryan M. Spears, Andy Tye, Jennifer L. Williamson, Chris Balfour, Mike Best, Michael Bowes, Sarah Breimann, Ian J. Brown, Annette Burden, Nathan Callaghan, Nancy B. Dise, Gareth Farr, Stacey L. Felgate, James Fishwick, Mike Fraser, Stuart Gibb, Pete J. Gilbert, Nina Godsell, Africa P. Gomez-Castillo, Geoff Hargreaves, Carolyn Harris, Oban Jones, Paul Kennedy, Anna Lichtschlag, Adrian P. Martin, Rebecca May, Edward Mawji, Ian Mounteney, Philip D. Nightingale, Justyna P. Olszewska, Stuart C. Painter, Christopher R. Pearce, M. Gloria Pereira, Kate Peel, Amy Pickard, John A. Stephens, Mark Stinchcombe, Barry Thornton, E. Malcolm S. Woodward, Deborah Yarrow, Daniel J. Mayor
Summary: The concentrations of particulate organic carbon (POC) and particulate organic nitrogen (PON) were evaluated in 13 British estuaries, and their sources were assessed using stable carbon and nitrogen isotopes. The results showed a high variability in POC and PON concentrations within the estuaries, indicating inputs and losses of organic material. The land cover of the catchment area appeared to influence the contribution of POC to the total organic carbon flux from the estuary to coastal waters.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2023)
Article
Environmental Sciences
J. E. Hatton, H. C. Ng, L. Meire, E. M. S. Woodward, M. J. Leng, C. D. Coath, A. Stuart-Lee, T. Wang, A. L. Annett, K. R. Hendry
Summary: Glaciers and ice sheets are rapidly warming due to climate change, and research suggests that glacial meltwaters provide important nutrients to downstream ecosystems. However, the fate of these nutrients in fjord environments is still uncertain. A study in southwest Greenland used concentration data and isotopic compositions to investigate silicon cycling in two contrasting fjords. The results suggest that glacially derived amorphous silica may play a role in modifying coastal waters within fjords.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2023)
Article
Geosciences, Multidisciplinary
Michael J. Whitehouse, Katharine R. Hendry, Geraint A. Tarling, Sally E. Thorpe, Petra Ten Hoopen
Summary: We have created a database of macronutrient data obtained from 20 oceanographic cruises conducted primarily around South Georgia and the Scotia Sea. The database includes measurements of nutrients such as silicate, phosphate, nitrate, ammonium, and nitrite, along with temperature and salinity data. This comprehensive dataset provides valuable information for studying the ecology of the Southern Ocean and its surrounding regions.
EARTH SYSTEM SCIENCE DATA
(2023)
Article
Geochemistry & Geophysics
Xinze Lu, Geoffrey J. Gilleaudeau, Brian Kendall
Summary: The Late Ordovician mass extinction is the first major extinction event in the Phanerozoic, but the reasons for the decline in global biodiversity before the extinction are not well understood.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2024)
Article
Geochemistry & Geophysics
Junyao Kang, Daniel D. Gregory, Benjamin Gill, Shiqiang Huang, Changxin Lai, Zhaoshan Chang, Huan Cui, Ivan Belousov, Shuhai Xiao
Summary: Sedimentary pyrite is an important geological archive, but it can be altered by diagenetic and hydrothermal processes. This study successfully trained machine learning algorithms to distinguish pyrite origins using trace element data. The approach was validated and applied to identify the origins of pyrite in two sedimentary successions in South China.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2024)