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Kléparski L, Beaugrand G, Ostle C, Edwards M, Skogen MD, Djeghri N, Hátún H. Ocean climate and hydrodynamics drive decadal shifts in Northeast Atlantic dinoflagellates. GLOBAL CHANGE BIOLOGY 2024; 30:e17163. [PMID: 38380701 DOI: 10.1111/gcb.17163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 12/04/2023] [Accepted: 12/26/2023] [Indexed: 02/22/2024]
Abstract
The abundance of large marine dinoflagellates has declined in the North Sea since 1958. Although hypotheses have been proposed to explain this diminution (increasing temperature and wind), the mechanisms behind this pattern have thus far remained elusive. In this article, we study the long-term changes in dinoflagellate biomass and biodiversity in relation to hydro-climatic conditions and circulation within the North Atlantic. Our results show that the decline in biomass has paralleled an increase in biodiversity caused by a temperature-induced northward movement of subtropical taxa along the European shelf-edge, and facilitated by changes in oceanic circulation (subpolar gyre contraction). However, major changes in North Atlantic hydrodynamics in the 2010s (subpolar gyre expansion and low-salinity anomaly) stopped this movement, which triggered a biodiversity collapse in the North Sea. Further, North Sea dinoflagellate biomass remained low because of warming. Our results, therefore, reveal that regional climate warming and changes in oceanic circulation strongly influenced shifts in dinoflagellate biomass and biodiversity.
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Affiliation(s)
- Loïck Kléparski
- UMR 8187-LOG-Laboratoire d'Océanologie et de Géosciences, Univ. Littoral Côte d'Opale, CNRS, Univ. Lille, Wimereux, France
- Continuous Plankton Recorder Survey, Marine Biological Association, Plymouth, UK
| | - Grégory Beaugrand
- UMR 8187-LOG-Laboratoire d'Océanologie et de Géosciences, Univ. Littoral Côte d'Opale, CNRS, Univ. Lille, Wimereux, France
| | - Clare Ostle
- Continuous Plankton Recorder Survey, Marine Biological Association, Plymouth, UK
| | - Martin Edwards
- Plymouth Marine Laboratory, Plymouth, UK
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, UK
| | | | - Nicolas Djeghri
- Continuous Plankton Recorder Survey, Marine Biological Association, Plymouth, UK
| | - Hjálmar Hátún
- Faroe Marine Research Institute, Tórshavn, Faroe Islands
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2
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Haine TWN, Siddiqui AH, Jiang W. Arctic freshwater impact on the Atlantic Meridional Overturning Circulation: status and prospects. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2023; 381:20220185. [PMID: 37866388 PMCID: PMC10590664 DOI: 10.1098/rsta.2022.0185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 07/11/2023] [Indexed: 10/24/2023]
Abstract
Arguably, the most conspicuous evidence for anthropogenic climate change lies in the Arctic Ocean. For example, the summer-time Arctic sea ice extent has declined over the last 40 years and the Arctic Ocean freshwater storage has increased over the last 30 years. Coupled climate models project that this extra freshwater will pass Greenland to enter the sub-polar North Atlantic Ocean (SPNA) in the coming decades. Coupled climate models also project that the Atlantic Meridional Overturning Circulation (AMOC) will weaken in the twenty-first century, associated with SPNA buoyancy increases. Yet, it remains unclear when the Arctic anthropogenic freshening signal will be detected in the SPNA, or what form the signal will take. Therefore, this article reviews and synthesizes the state of knowledge on Arctic Ocean and SPNA salinity variations and their causes. This article focuses on the export processes in data-constrained ocean circulation model hindcasts. One challenge is to quantify and understand the relative importance of different competing processes. This article also discusses the prospects to detect the emergence of Arctic anthropogenic freshening and the likely impacts on the AMOC. For this issue, the challenge is to distinguish anthropogenic signals from natural variability. This article is part of a discussion meeting issue 'Atlantic overturning: new observations and challenges'.
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Affiliation(s)
- Thomas W. N. Haine
- Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Ali H. Siddiqui
- Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Wenrui Jiang
- Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
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3
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Lu W, Oppo DW, Gebbie G, Thornalley DJR. Surface climate signals transmitted rapidly to deep North Atlantic throughout last millennium. Science 2023; 382:834-839. [PMID: 37972177 DOI: 10.1126/science.adf1646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 10/11/2023] [Indexed: 11/19/2023]
Abstract
Instrumental observations of subsurface ocean warming imply that ocean heat uptake has slowed 20th-century surface warming. We present high-resolution records from subpolar North Atlantic sediments that are consistent with instrumental observations of surface and deep warming/freshening and in addition reconstruct the surface-deep relation of the last 1200 years. Sites from ~1300 meters and deeper suggest an ~0.5 degrees celsius cooling across the Medieval Climate Anomaly to Little Ice Age transition that began ~1350 ± 50 common era (CE), whereas surface records suggest asynchronous cooling onset spanning ~600 years. These data suggest that ocean circulation integrates surface variability that is transmitted rapidly to depth by the Atlantic Meridional Ocean Circulation, implying that the ocean moderated Earth's surface temperature throughout the last millennium as it does today.
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Affiliation(s)
- Wanyi Lu
- Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Delia W Oppo
- Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | | | - David J R Thornalley
- Woods Hole Oceanographic Institution, Woods Hole, MA, USA
- Department of Geography, University College London, London, UK
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4
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Reconstruction of Subsurface Salinity Structure in the South China Sea Using Satellite Observations: A LightGBM-Based Deep Forest Method. REMOTE SENSING 2022. [DOI: 10.3390/rs14143494] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Accurately estimating the ocean’s interior structures using sea surface data is of vital importance for understanding the complexities of dynamic ocean processes. In this study, we proposed an advanced machine-learning method, the Light Gradient Boosting Machine (LightGBM)-based Deep Forest (LGB-DF) method, to estimate the ocean subsurface salinity structure (OSSS) in the South China Sea (SCS) by using sea surface data from multiple satellite observations. We selected sea surface salinity (SSS), sea surface temperature (SST), sea surface height (SSH), sea surface wind (SSW, decomposed into eastward wind speed (USSW) and northward wind speed (VSSW) components), and the geographical information (including longitude and latitude) as input data to estimate OSSS in the SCS. Argo data were used to train and validate the LGB-DF model. The model performance was evaluated using root mean square error (RMSE), normalized root mean square error (NRMSE), and determination coefficient (R2). The results showed that the LGB-DF model had a good performance and outperformed the traditional LightGBM model in the estimation of OSSS. The proposed LGB-DF model using sea surface data by SSS/SST/SSH and SSS/SST/SSH/SSW performed less satisfactorily than when considering the contribution of the wind speed and geographical information, indicating that these are important parameters for accurately estimating OSSS. The performance of the LGB-DF model was found to vary with season and water depth. Better estimation accuracy was obtained in winter and autumn, which was due to weaker stratification. This method provided important technical support for estimating the OSSS from satellite-derived sea surface data, which offers a novel insight into oceanic observations.
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5
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Variability and Uncertainty of Satellite Sea Surface Salinity in the Subpolar North Atlantic (2010–2019). REMOTE SENSING 2020. [DOI: 10.3390/rs12132092] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Satellite remote sensing of sea surface salinity (SSS) in the recent decade (2010–2019) has proven the capability of L-band (1.4 GHz) measurements to resolve SSS spatiotemporal variability in the tropical and subtropical oceans. However, the fidelity of SSS retrievals in cold waters at mid-high latitudes has yet to be established. Here, four SSS products derived from two satellite missions were evaluated in the subpolar North Atlantic Ocean in reference to two in situ gridded products. Harmonic analysis of annual and semiannual cycles in in situ products revealed that seasonal variations of SSS are dominated by an annual cycle, with a maximum in March and a minimum in September. The annual amplitudes are larger (>0.3 practical salinity scale (pss)) in the western basin where surface waters are colder and fresher, and weaker (~0.06 pss) in the eastern basin where surface waters are warmer and saltier. Satellite SSS products have difficulty producing the right annual cycle, particularly in the Labrador/Irminger seas where the SSS seasonality is dictated by the influx of Arctic low-salinity waters along the boundary currents. The study also found that there are basin-scale, time-varying drifts in the decade-long SMOS data records, which need to be corrected before the datasets can be used for studying climate variability of SSS.
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Ocean circulation causes the largest freshening event for 120 years in eastern subpolar North Atlantic. Nat Commun 2020; 11:585. [PMID: 31996687 PMCID: PMC6989661 DOI: 10.1038/s41467-020-14474-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 12/04/2019] [Indexed: 12/03/2022] Open
Abstract
The Atlantic Ocean overturning circulation is important to the climate system because it carries heat and carbon northward, and from the surface to the deep ocean. The high salinity of the subpolar North Atlantic is a prerequisite for overturning circulation, and strong freshening could herald a slowdown. We show that the eastern subpolar North Atlantic underwent extreme freshening during 2012 to 2016, with a magnitude never seen before in 120 years of measurements. The cause was unusual winter wind patterns driving major changes in ocean circulation, including slowing of the North Atlantic Current and diversion of Arctic freshwater from the western boundary into the eastern basins. We find that wind-driven routing of Arctic-origin freshwater intimately links conditions on the North West Atlantic shelf and slope region with the eastern subpolar basins. This reveals the importance of atmospheric forcing of intra-basin circulation in determining the salinity of the subpolar North Atlantic. The Atlantic Ocean overturning circulation is important to the global climate system. Here the authors show that eastern subpolar North Atlantic underwent extreme freshening during 2012 to 2016, with a magnitude never seen before in 120 years of surface measurements.
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7
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Industrial-era decline in subarctic Atlantic productivity. Nature 2019; 569:551-555. [PMID: 31061499 DOI: 10.1038/s41586-019-1181-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 04/08/2019] [Indexed: 11/08/2022]
Abstract
Marine phytoplankton have a crucial role in the modulation of marine-based food webs1, fishery yields2 and the global drawdown of atmospheric carbon dioxide3. However, owing to sparse measurements before satellite monitoring in the twenty-first century, the long-term response of planktonic stocks to climate forcing is unknown. Here, using a continuous, multi-century record of subarctic Atlantic marine productivity, we show that a marked 10 ± 7% decline in net primary productivity has occurred across this highly productive ocean basin over the past two centuries. We support this conclusion by the application of a marine-productivity proxy, established using the signal of the planktonic-derived aerosol methanesulfonic acid, which is commonly identified across an array of Greenlandic ice cores. Using contemporaneous satellite-era observations, we demonstrate the use of this signal as a robust and high-resolution proxy for past variations in spatially integrated marine productivity. We show that the initiation of declining subarctic Atlantic productivity broadly coincides with the onset of Arctic surface warming4, and that productivity strongly covaries with regional sea-surface temperatures and basin-wide gyre circulation strength over recent decades. Taken together, our results suggest that the decline in industrial-era productivity may be evidence of the predicted5 collapse of northern Atlantic planktonic stocks in response to a weakened Atlantic Meridional Overturning Circulation6-8. Continued weakening of this Atlantic Meridional Overturning Circulation, as projected for the twenty-first century9,10, may therefore result in further productivity declines across this globally relevant region.
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8
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Balaguru K, Doney SC, Bianucci L, Rasch PJ, Leung LR, Yoon JH, Lima ID. Linking deep convection and phytoplankton blooms in the northern Labrador Sea in a changing climate. PLoS One 2018; 13:e0191509. [PMID: 29370224 PMCID: PMC5784959 DOI: 10.1371/journal.pone.0191509] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 01/05/2018] [Indexed: 12/03/2022] Open
Abstract
Wintertime convective mixing plays a pivotal role in the sub-polar North Atlantic spring phytoplankton blooms by favoring phytoplankton survival in the competition between light-dependent production and losses due to grazing and gravitational settling. We use satellite and ocean reanalyses to show that the area-averaged maximum winter mixed layer depth is positively correlated with April chlorophyll concentration in the northern Labrador Sea. A simple theoretical framework is developed to understand the relative roles of winter/spring convection and gravitational sedimentation in spring blooms in this region. Combining climate model simulations that project a weakening of wintertime Labrador Sea convection from Arctic sea ice melt with our framework suggests a potentially significant reduction in the initial fall phytoplankton population that survive the winter to seed the region’s spring bloom by the end of the 21st century.
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Affiliation(s)
- Karthik Balaguru
- Marine Sciences Laboratory, Pacific Northwest National Laboratory, Seattle, WA, United States of America - 98109
- Atmospheric Sciences & Global Change Division, Pacific Northwest National Laboratory, Richland, WA, United States of America - 99354
- * E-mail:
| | - Scott C. Doney
- Now at Department of Environmental Sciences, University of Virginia, Charlottesville, VA, United States of America - 22904
- Woods Hole Oceanographic Institution, Woods Hole, MA, United States of America - 02543
| | - Laura Bianucci
- Marine Sciences Laboratory, Pacific Northwest National Laboratory, Seattle, WA, United States of America - 98109
- Now at Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney BC, Canada - V8L 4B2
| | - Philip J. Rasch
- Atmospheric Sciences & Global Change Division, Pacific Northwest National Laboratory, Richland, WA, United States of America - 99354
| | - L. Ruby Leung
- Atmospheric Sciences & Global Change Division, Pacific Northwest National Laboratory, Richland, WA, United States of America - 99354
| | - Jin-Ho Yoon
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| | - Ivan D. Lima
- Woods Hole Oceanographic Institution, Woods Hole, MA, United States of America - 02543
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9
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Gonzalez-Romero R, Suarez-Ulloa V, Rodriguez-Casariego J, Garcia-Souto D, Diaz G, Smith A, Pasantes JJ, Rand G, Eirin-Lopez JM. Effects of Florida Red Tides on histone variant expression and DNA methylation in the Eastern oyster Crassostrea virginica. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2017; 186:196-204. [PMID: 28315825 DOI: 10.1016/j.aquatox.2017.03.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 03/02/2017] [Accepted: 03/03/2017] [Indexed: 06/06/2023]
Abstract
Massive algal proliferations known as Harmful Algal Blooms (HABs) represent one of the most important threats to coastal areas. Among them, the so-called Florida Red Tides (FRTs, caused by blooms of the dinoflagellate Karenia brevis and associated brevetoxins) are particularly detrimental in the southeastern U.S., causing high mortality rates and annual losses in excess of $40 million. The ability of marine organisms to cope with environmental stressors (including those produced during HABs) is influenced by genetic and epigenetic mechanisms, the latter resulting in phenotypic changes caused by heritable modifications in gene expression, without involving changes in the genetic (DNA) sequence. Yet, studies examining cause-effect relationships between environmental stressors, specific epigenetic mechanisms and subsequent responses are still lacking. The present work contributes to increase this knowledge by investigating the effects of Florida Red Tides on two types of mechanisms participating in the epigenetic memory of Eastern oysters: histone variants and DNA methylation. For that purpose, a HAB simulation was conducted in laboratory conditions, exposing oysters to increasing concentrations of K. brevis. The obtained results revealed, for the first time, the existence of H2A.X, H2A.Z and macroH2A genes in this organism, encoding histone variants potentially involved in the maintenance of genome integrity during responses to the genotoxic effect of brevetoxins. Additionally, an increase in H2A.X phosphorylation (γH2A.X, a marker of DNA damage) and a decrease in global DNA methylation were observed as the HAB simulation progressed. Overall, the present work provides a basis to better understand how epigenetic mechanisms participate in responses to environmental stress in marine invertebrates, opening new avenues to incorporate environmental epigenetics approaches into management and conservation programs.
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Affiliation(s)
- Rodrigo Gonzalez-Romero
- Environmental Epigenetics Group, Department of Biological Sciences, Florida International University, North Miami, FL 33181, USA
| | - Victoria Suarez-Ulloa
- Environmental Epigenetics Group, Department of Biological Sciences, Florida International University, North Miami, FL 33181, USA
| | - Javier Rodriguez-Casariego
- Environmental Epigenetics Group, Department of Biological Sciences, Florida International University, North Miami, FL 33181, USA; Ecotoxicology and Risk Assessment Laboratory, Southeast Environmental Research Center, Florida International University, North Miami, FL 33181, USA
| | - Daniel Garcia-Souto
- Departamento de Bioquimica, Xenetica e Inmunoloxia, Universidade de Vigo, E-36310 Vigo, Spain
| | - Gabriel Diaz
- Environmental Epigenetics Group, Department of Biological Sciences, Florida International University, North Miami, FL 33181, USA
| | - Abraham Smith
- Ecotoxicology and Risk Assessment Laboratory, Southeast Environmental Research Center, Florida International University, North Miami, FL 33181, USA
| | - Juan Jose Pasantes
- Departamento de Bioquimica, Xenetica e Inmunoloxia, Universidade de Vigo, E-36310 Vigo, Spain
| | - Gary Rand
- Ecotoxicology and Risk Assessment Laboratory, Southeast Environmental Research Center, Florida International University, North Miami, FL 33181, USA
| | - Jose M Eirin-Lopez
- Environmental Epigenetics Group, Department of Biological Sciences, Florida International University, North Miami, FL 33181, USA.
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Scheffers BR, De Meester L, Bridge TCL, Hoffmann AA, Pandolfi JM, Corlett RT, Butchart SHM, Pearce-Kelly P, Kovacs KM, Dudgeon D, Pacifici M, Rondinini C, Foden WB, Martin TG, Mora C, Bickford D, Watson JEM. The broad footprint of climate change from genes to biomes to people. Science 2017; 354:354/6313/aaf7671. [PMID: 27846577 DOI: 10.1126/science.aaf7671] [Citation(s) in RCA: 490] [Impact Index Per Article: 70.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Most ecological processes now show responses to anthropogenic climate change. In terrestrial, freshwater, and marine ecosystems, species are changing genetically, physiologically, morphologically, and phenologically and are shifting their distributions, which affects food webs and results in new interactions. Disruptions scale from the gene to the ecosystem and have documented consequences for people, including unpredictable fisheries and crop yields, loss of genetic diversity in wild crop varieties, and increasing impacts of pests and diseases. In addition to the more easily observed changes, such as shifts in flowering phenology, we argue that many hidden dynamics, such as genetic changes, are also taking place. Understanding shifts in ecological processes can guide human adaptation strategies. In addition to reducing greenhouse gases, climate action and policy must therefore focus equally on strategies that safeguard biodiversity and ecosystems.
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Affiliation(s)
- Brett R Scheffers
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL 32611-0430, USA.
| | - Luc De Meester
- Laboratory of Aquatic Ecology, Evolution and Conservation, KU Leuven, Ch. De Beriotstraat 32, 3000 Leuven, Belgium
| | - Tom C L Bridge
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville QLD 4811, Australia.,Queensland Museum, Townsville, Queensland 4810, Australia
| | - Ary A Hoffmann
- Bio21 Institute, School of Biosciences, University of Melbourne, Victoria 3010, Australia
| | - John M Pandolfi
- School of Biological Sciences and the Australian Research Council Centre of Excellence for Coral Reef Studies, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Richard T Corlett
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Gardens, Chinese Academy of Sciences, Yunnan 666303, China
| | - Stuart H M Butchart
- BirdLife International, David Attenborough Building, Pembroke Street, Cambridge CB2 3QZ, UK.,Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | | | - Kit M Kovacs
- Norwegian Polar Institute, FRAM Centre, 9296 Tromsø, Norway
| | - David Dudgeon
- School of Biological Sciences, University of Hong Kong, Hong Kong SAR, China
| | - Michela Pacifici
- Global Mammal Assessment Program, Department of Biology and Biotechnologies, Sapienza Università di Roma, Viale dell'Università 32, I-00185 Rome, Italy
| | - Carlo Rondinini
- Global Mammal Assessment Program, Department of Biology and Biotechnologies, Sapienza Università di Roma, Viale dell'Università 32, I-00185 Rome, Italy
| | - Wendy B Foden
- Department of Botany and Zoology, University of Stellenbosch, P/Bag X1, Matieland, 7602 Stellenbosch, South Africa
| | - Tara G Martin
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Camilo Mora
- Department of Geography, University of Hawaii, Honolulu, Hawaii, USA
| | - David Bickford
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, 117543, Singapore
| | - James E M Watson
- School of Geography, Planning and Environmental Management, The University of Queensland, Brisbane, Queensland 4072, Australia.,Global Conservation Program, Wildlife Conservation Society, 2300 Southern Boulevard, Bronx, NY 10460, USA
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11
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Sgubin G, Swingedouw D, Drijfhout S, Mary Y, Bennabi A. Abrupt cooling over the North Atlantic in modern climate models. Nat Commun 2017; 8:ncomms14375. [PMID: 28198383 PMCID: PMC5330854 DOI: 10.1038/ncomms14375] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 12/21/2016] [Indexed: 11/29/2022] Open
Abstract
Observations over the 20th century evidence no long-term warming in the subpolar North Atlantic (SPG). This region even experienced a rapid cooling around 1970, raising a debate over its potential reoccurrence. Here we assess the risk of future abrupt SPG cooling in 40 climate models from the fifth Coupled Model Intercomparison Project (CMIP5). Contrary to the long-term SPG warming trend evidenced by most of the models, 17.5% of the models (7/40) project a rapid SPG cooling, consistent with a collapse of the local deep-ocean convection. Uncertainty in projections is associated with the models’ varying capability in simulating the present-day SPG stratification, whose realistic reproduction appears a necessary condition for the onset of a convection collapse. This event occurs in 45.5% of the 11 models best able to simulate the observed SPG stratification. Thus, due to systematic model biases, the CMIP5 ensemble as a whole underestimates the chance of future abrupt SPG cooling, entailing crucial implications for observation and adaptation policy. Concerns on climate change include the risk of abrupt cooling in the North Atlantic. Here, the authors analyse CMIP5 projections and show that a convection collapse in the subpolar gyre can cool this region by up to 3°C in 10 years, which is as likely to occur by 2100 as a continuous warming.
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Affiliation(s)
- Giovanni Sgubin
- Laboratoire des Sciences du Climat et de l'Environnement (LSCE), Institut Pierre Simon Laplace (IPSL), 91191 Gif-sur-Yvette, France.,Environnements et Paleoenvironnements Oceaniques et Continenteaux (EPOC), UMR CNRS 5805, Université de Bordeaux, 33615 Pessac, France
| | - Didier Swingedouw
- Environnements et Paleoenvironnements Oceaniques et Continenteaux (EPOC), UMR CNRS 5805, Université de Bordeaux, 33615 Pessac, France
| | - Sybren Drijfhout
- Royal Netherlands Meteorological Institute (KNMI), 3730AE De Bilt, The Netherlands.,National Oceanography Centre (NOC), University of Southampton, Southampton SO14 3ZH, UK
| | - Yannick Mary
- Environnements et Paleoenvironnements Oceaniques et Continenteaux (EPOC), UMR CNRS 5805, Université de Bordeaux, 33615 Pessac, France
| | - Amine Bennabi
- Institut de Mecanique et d'Ingenierie (I2M), Université de Bordeaux, 33615 Pessac, France
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12
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Linkages between atmospheric blocking, sea ice export through Fram Strait and the Atlantic Meridional Overturning Circulation. Sci Rep 2016; 6:32881. [PMID: 27619955 PMCID: PMC5020648 DOI: 10.1038/srep32881] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 08/16/2016] [Indexed: 11/28/2022] Open
Abstract
As a key persistent component of the atmospheric dynamics, the North Atlantic blocking activity has been linked to extreme climatic phenomena in the European sector. It has also been linked to Atlantic multidecadal ocean variability, but its potential links to rapid oceanic changes have not been investigated. Using a global ocean-sea ice model forced with atmospheric reanalysis data, here it is shown that the 1962–1966 period of enhanced blocking activity over Greenland resulted in anomalous sea ice accumulation in the Arctic and ended with a sea ice flush from the Arctic into the North Atlantic Ocean through Fram Strait. This event induced a significant decrease of Labrador Sea water surface salinity and an abrupt weakening of the Atlantic Meridional Overturning Circulation (AMOC) during the 1970s. These results have implications for the prediction of rapid AMOC changes and indicate that an important part of the atmosphere-ocean dynamics at mid- and high latitudes requires a proper representation of the Fram Strait sea ice transport and of the synoptic scale variability such as atmospheric blocking, which is a challenge for current coupled climate models.
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13
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Arimi KS. Determinants of climate change adaptation strategies used by fish farmers in Epe Local Government Area of Lagos State, Nigeria. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2014; 94:1470-6. [PMID: 24154939 DOI: 10.1002/jsfa.6452] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 10/02/2013] [Accepted: 10/23/2013] [Indexed: 05/11/2023]
Abstract
BACKGROUND Undesirable impacts of climate change have been a common occurrence that has made fish farmers in developing countries adopt some climate-change adaptation strategies. However, little is known about determinants of climate-change adaptation strategies used by these fish farmers. This study, therefore, articulates novelties on adaptation to climate change, as well ascertains determinants of adaptation strategies used by fish farmers in Epe, Lagos State, Nigeria. RESULTS Climate change adaptation strategies mostly used by fish farmers include frequent seeking for early warning information about climate change (76.7%) and avoidance of areas susceptible to flooding (60.0%). Climate-change adaptation strategies used by fish farmers were significantly influenced by access to early warning information (β = 7.21), knowledge of farmers about climate change adaptation strategies (β = 8.86), access to capital (β = 28.25), and participation in workshop and conferences (β = 37.19) but were reduced by number of fish stocking (β = -2.06). CONCLUSION The adaptation strategies used by fish farmers were autonomous and mostly determined by the access to credit facilities and information. Development policy should focus on carbon capture and storage technology in order to reduce adverse impacts of climate change, as well as making early warning information on climate change available to fish farmers. These will enhance adaptation to climate change.
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Affiliation(s)
- Kayode S Arimi
- Department of Agricultural Extension and Rural Development, University of Ibadan, Oyo State, Nigeria
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14
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Hetzinger S, Halfar J, Zack T, Mecking JV, Kunz BE, Jacob DE, Adey WH. Coralline algal barium as indicator for 20th century northwestern North Atlantic surface ocean freshwater variability. Sci Rep 2014; 3:1761. [PMID: 23636135 PMCID: PMC3641520 DOI: 10.1038/srep01761] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 04/12/2013] [Indexed: 11/30/2022] Open
Abstract
During the past decades climate and freshwater dynamics in the northwestern North Atlantic have undergone major changes. Large-scale freshening episodes, related to polar freshwater pulses, have had a strong influence on ocean variability in this climatically important region. However, little is known about variability before 1950, mainly due to the lack of long-term high-resolution marine proxy archives. Here we present the first multidecadal-length records of annually resolved Ba/Ca variations from Northwest Atlantic coralline algae. We observe positive relationships between algal Ba/Ca ratios from two Newfoundland sites and salinity observations back to 1950. Both records capture episodical multi-year freshening events during the 20th century. Variability in algal Ba/Ca is sensitive to freshwater-induced changes in upper ocean stratification, which affect the transport of cold, Ba-enriched deep waters onto the shelf (highly stratified equals less Ba/Ca). Algal Ba/Ca ratios therefore may serve as a new resource for reconstructing past surface ocean freshwater changes.
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Affiliation(s)
- S Hetzinger
- CPS-Department, University of Toronto Mississauga, 3359 Mississauga Rd. N, Mississauga, ON, L5L 1C6, Canada.
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15
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Assessing the meridional atmosphere and ocean energy transport in a varying climate. CHINESE SCIENCE BULLETIN-CHINESE 2013. [DOI: 10.1007/s11434-013-5665-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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16
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The Arctic and Subarctic Oceans/Seas. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/b978-0-12-391851-2.00017-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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17
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Durack PJ, Wijffels SE, Boyer TP. Long-term Salinity Changes and Implications for the Global Water Cycle. INTERNATIONAL GEOPHYSICS 2013. [DOI: 10.1016/b978-0-12-391851-2.00028-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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18
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Abstract
Although Echinodermata is one of the only stenohaline phyla in the animal kingdom, several species show remarkable abilities to acclimate and survive in euryhaline habitats. The last comprehensive review of this topic was over 25 years ago and much work has been published since. These recent studies expand the field reports of species living in hyposaline environments and detail experimental research on the responses, physiological range, and limits of echinoderms to salinity challenges. I provide a brief review of the historical concepts and measures of salinity and relate this overview to the physiological and ecological studies on echinoderms. Many marine biologists are not aware that chemical oceanographers advocate abandoning today's commonly used measure of salinity, 'PSU', in favour of absolute salinity (SA)-a return to the ppt (‰) metric. The literature survey reveals only one euryhaline-tolerant species in the Southern Hemisphere (there are 42 in the North) and more euryhaline species in the geologically older, brackish seas. The green sea urchin, Strongylocentrotus droebachiensis, is one of the most tolerant echinoids to hyposalinity. Different source populations have varying levels of acclimation and tolerance to hyposalinity. Experiments show that green urchins previously unexposed to hyposalinity experience a clear decrease in growth rates; however, this adverse effect is short lived. Green urchins already acclimated to hyposalinity can endure intense and repeated bouts and grow at the same rate of urchins not exposed. Promising future work on the physiological and cellular mechanisms of hyposalinity acclimation includes comparative studies of the role of heat shock proteins in the response to changing salinities.
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Affiliation(s)
- Michael P Russell
- Biology Department, Villanova University, Villanova, Pennsylvania, USA.
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19
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Robinson LF, Siddall M. Palaeoceanography: motivations and challenges for the future. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2012; 370:5540-5566. [PMID: 23129712 DOI: 10.1098/rsta.2012.0396] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The ocean interacts with the atmosphere, biosphere and cryosphere in a complex way, modulating climate through the storage and transport of heat, nutrients and carbon. As such, it is important that we understand the ways in which the ocean behaves and the factors that can lead to change. In order to gain this understanding, we need to look back into the past, on time scales from recent decadal-scale change, through the abrupt changes of the Pleistocene and back to times when the Earth's climate was significantly different than the Holocene. A key challenge facing the field of palaeoceanography is to combine data and modelling in a common framework. Coupling palaeo-data and models should improve our knowledge of how the Earth works, and perhaps of more direct societal relevance, might enable us to provide better predictive capabilities in climate modelling. In this discussion paper, we examine the motivations, past successes and challenges facing palaeoceanographic studies. We then suggest a number of areas and approaches that we believe will allow palaeoceanography to continue to provide new insights into processes that affect future climate change.
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20
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21
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Wanninkhof R, Doney SC, Bullister JL, Levine NM, Warner M, Gruber N. Detecting anthropogenic CO2changes in the interior Atlantic Ocean between 1989 and 2005. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010jc006251] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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22
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Koprivnikar J, Lim D, Fu C, Brack SHM. Effects of temperature, salinity, and pH on the survival and activity of marine cercariae. Parasitol Res 2010; 106:1167-77. [DOI: 10.1007/s00436-010-1779-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Accepted: 01/19/2010] [Indexed: 11/28/2022]
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23
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Increase in Agulhas leakage due to poleward shift of Southern Hemisphere westerlies. Nature 2010; 462:495-8. [PMID: 19940923 DOI: 10.1038/nature08519] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Accepted: 09/16/2009] [Indexed: 11/08/2022]
Abstract
The transport of warm and salty Indian Ocean waters into the Atlantic Ocean-the Agulhas leakage-has a crucial role in the global oceanic circulation and thus the evolution of future climate. At present these waters provide the main source of heat and salt for the surface branch of the Atlantic meridional overturning circulation (MOC). There is evidence from past glacial-to-interglacial variations in foraminiferal assemblages and model studies that the amount of Agulhas leakage and its corresponding effect on the MOC has been subject to substantial change, potentially linked to latitudinal shifts in the Southern Hemisphere westerlies. A progressive poleward migration of the westerlies has been observed during the past two to three decades and linked to anthropogenic forcing, but because of the sparse observational records it has not been possible to determine whether there has been a concomitant response of Agulhas leakage. Here we present the results of a high-resolution ocean general circulation model to show that the transport of Indian Ocean waters into the South Atlantic via the Agulhas leakage has increased during the past decades in response to the change in wind forcing. The increased leakage has contributed to the observed salinification of South Atlantic thermocline waters. Both model and historic measurements off South America suggest that the additional Indian Ocean waters have begun to invade the North Atlantic, with potential implications for the future evolution of the MOC.
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24
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Riebesell U, Körtzinger A, Oschlies A. Sensitivities of marine carbon fluxes to ocean change. Proc Natl Acad Sci U S A 2009; 106:20602-9. [PMID: 19995981 PMCID: PMC2791567 DOI: 10.1073/pnas.0813291106] [Citation(s) in RCA: 203] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Indexed: 11/18/2022] Open
Abstract
Throughout Earth's history, the oceans have played a dominant role in the climate system through the storage and transport of heat and the exchange of water and climate-relevant gases with the atmosphere. The ocean's heat capacity is approximately 1,000 times larger than that of the atmosphere, its content of reactive carbon more than 60 times larger. Through a variety of physical, chemical, and biological processes, the ocean acts as a driver of climate variability on time scales ranging from seasonal to interannual to decadal to glacial-interglacial. The same processes will also be involved in future responses of the ocean to global change. Here we assess the responses of the seawater carbonate system and of the ocean's physical and biological carbon pumps to (i) ocean warming and the associated changes in vertical mixing and overturning circulation, and (ii) ocean acidification and carbonation. Our analysis underscores that many of these responses have the potential for significant feedback to the climate system. Because several of the underlying processes are interlinked and nonlinear, the sign and magnitude of the ocean's carbon cycle feedback to climate change is yet unknown. Understanding these processes and their sensitivities to global change will be crucial to our ability to project future climate change.
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Affiliation(s)
- Ulf Riebesell
- Marine Biogeochemistry, Leibniz Institute of Marine Sciences, IFM-GEOMAR, Düsternbrooker Weg 20, 24105 Kiel, Germany.
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25
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Keller BD, Gleason DF, McLeod E, Woodley CM, Airamé S, Causey BD, Friedlander AM, Grober-Dunsmore R, Johnson JE, Miller SL, Steneck RS. Climate change, coral reef ecosystems, and management options for marine protected areas. ENVIRONMENTAL MANAGEMENT 2009; 44:1069-88. [PMID: 19636605 PMCID: PMC2791481 DOI: 10.1007/s00267-009-9346-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2008] [Accepted: 06/28/2009] [Indexed: 05/21/2023]
Abstract
Marine protected areas (MPAs) provide place-based management of marine ecosystems through various degrees and types of protective actions. Habitats such as coral reefs are especially susceptible to degradation resulting from climate change, as evidenced by mass bleaching events over the past two decades. Marine ecosystems are being altered by direct effects of climate change including ocean warming, ocean acidification, rising sea level, changing circulation patterns, increasing severity of storms, and changing freshwater influxes. As impacts of climate change strengthen they may exacerbate effects of existing stressors and require new or modified management approaches; MPA networks are generally accepted as an improvement over individual MPAs to address multiple threats to the marine environment. While MPA networks are considered a potentially effective management approach for conserving marine biodiversity, they should be established in conjunction with other management strategies, such as fisheries regulations and reductions of nutrients and other forms of land-based pollution. Information about interactions between climate change and more "traditional" stressors is limited. MPA managers are faced with high levels of uncertainty about likely outcomes of management actions because climate change impacts have strong interactions with existing stressors, such as land-based sources of pollution, overfishing and destructive fishing practices, invasive species, and diseases. Management options include ameliorating existing stressors, protecting potentially resilient areas, developing networks of MPAs, and integrating climate change into MPA planning, management, and evaluation.
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Affiliation(s)
- Brian D Keller
- Southeast Atlantic, Gulf of Mexico, and Caribbean Region, NOAA Office of National Marine Sanctuaries, St. Petersburg, FL 33701, USA.
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26
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Zheng Y, Giese BS. Ocean heat transport in Simple Ocean Data Assimilation: Structure and mechanisms. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jc005190] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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27
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Proshutinsky A, Krishfield R, Timmermans ML, Toole J, Carmack E, McLaughlin F, Williams WJ, Zimmermann S, Itoh M, Shimada K. Beaufort Gyre freshwater reservoir: State and variability from observations. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jc005104] [Citation(s) in RCA: 299] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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28
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Psillakis E, Cheng J, Hoffmann MR, Colussi AJ. Enrichment Factors of Perfluoroalkyl Oxoanions at the Air/Water Interface. J Phys Chem A 2009; 113:8826-9. [DOI: 10.1021/jp902795m] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Elefteria Psillakis
- W. M. Keck Laboratories, California Institute of Technology, Pasadena, California 91125
| | - Jie Cheng
- W. M. Keck Laboratories, California Institute of Technology, Pasadena, California 91125
| | - M. R. Hoffmann
- W. M. Keck Laboratories, California Institute of Technology, Pasadena, California 91125
| | - A. J. Colussi
- W. M. Keck Laboratories, California Institute of Technology, Pasadena, California 91125
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29
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Southern Ocean frontal structure and sea-ice formation rates revealed by elephant seals. Proc Natl Acad Sci U S A 2008; 105:11634-9. [PMID: 18695241 DOI: 10.1073/pnas.0800790105] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Polar regions are particularly sensitive to climate change, with the potential for significant feedbacks between ocean circulation, sea ice, and the ocean carbon cycle. However, the difficulty in obtaining in situ data means that our ability to detect and interpret change is very limited, especially in the Southern Ocean, where the ocean beneath the sea ice remains almost entirely unobserved and the rate of sea-ice formation is poorly known. Here, we show that southern elephant seals (Mirounga leonina) equipped with oceanographic sensors can measure ocean structure and water mass changes in regions and seasons rarely observed with traditional oceanographic platforms. In particular, seals provided a 30-fold increase in hydrographic profiles from the sea-ice zone, allowing the major fronts to be mapped south of 60 degrees S and sea-ice formation rates to be inferred from changes in upper ocean salinity. Sea-ice production rates peaked in early winter (April-May) during the rapid northward expansion of the pack ice and declined by a factor of 2 to 3 between May and August, in agreement with a three-dimensional coupled ocean-sea-ice model. By measuring the high-latitude ocean during winter, elephant seals fill a "blind spot" in our sampling coverage, enabling the establishment of a truly global ocean-observing system.
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30
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Harding AMA, Hobson KA, Walkusz W, Dmoch K, Karnovsky NJ, Van Pelt TI, Lifjeld JT. Can stable isotope (δ13C and δ15N) measurements of little auk (Alle alle) adults and chicks be used to track changes in high-Arctic marine foodwebs? Polar Biol 2008. [DOI: 10.1007/s00300-008-0413-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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31
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MacDonald GM, Kremenetski KV, Smith LC, Hidalgo HG. Recent Eurasian river discharge to the Arctic Ocean in the context of longer-term dendrohydrological records. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jg000333] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- G. M. MacDonald
- Department of Geography; University of California, Los Angeles; Los Angeles California USA
| | - K. V. Kremenetski
- Department of Geography; University of California, Los Angeles; Los Angeles California USA
| | - L. C. Smith
- Department of Geography; University of California, Los Angeles; Los Angeles California USA
| | - H. G. Hidalgo
- Scripps Institute of Oceanography; University of California, San Diego; La Jolla California USA
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32
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Smith LC, Pavelsky TM, MacDonald GM, Shiklomanov AI, Lammers RB. Rising minimum daily flows in northern Eurasian rivers: A growing influence of groundwater in the high-latitude hydrologic cycle. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jg000327] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Laurence C. Smith
- Department of Geography; University of California; Los Angeles California USA
| | - Tamlin M. Pavelsky
- Department of Geography; University of California; Los Angeles California USA
| | - Glen M. MacDonald
- Department of Geography; University of California; Los Angeles California USA
| | - Alexander I. Shiklomanov
- Institute for the Study of Earth, Oceans and Space; University of New Hampshire; Durham New Hampshire USA
| | - Richard B. Lammers
- Institute for the Study of Earth, Oceans and Space; University of New Hampshire; Durham New Hampshire USA
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33
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Abstract
Current global fisheries production of approximately 160 million tons is rising as a result of increases in aquaculture production. A number of climate-related threats to both capture fisheries and aquaculture are identified, but we have low confidence in predictions of future fisheries production because of uncertainty over future global aquatic net primary production and the transfer of this production through the food chain to human consumption. Recent changes in the distribution and productivity of a number of fish species can be ascribed with high confidence to regional climate variability, such as the El Niño-Southern Oscillation. Future production may increase in some high-latitude regions because of warming and decreased ice cover, but the dynamics in low-latitude regions are governed by different processes, and production may decline as a result of reduced vertical mixing of the water column and, hence, reduced recycling of nutrients. There are strong interactions between the effects of fishing and the effects of climate because fishing reduces the age, size, and geographic diversity of populations and the biodiversity of marine ecosystems, making both more sensitive to additional stresses such as climate change. Inland fisheries are additionally threatened by changes in precipitation and water management. The frequency and intensity of extreme climate events is likely to have a major impact on future fisheries production in both inland and marine systems. Reducing fishing mortality in the majority of fisheries, which are currently fully exploited or overexploited, is the principal feasible means of reducing the impacts of climate change.
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34
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Slater AG, Bohn TJ, McCreight JL, Serreze MC, Lettenmaier DP. A multimodel simulation of pan-Arctic hydrology. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jg000303] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- A. G. Slater
- National Snow and Ice Data Center, Cooperative Institute for Research in Environmental Sciences; University of Colorado; Boulder Colorado USA
| | - T. J. Bohn
- Department of Civil and Environmental Engineering; University of Washington; Seattle Washington USA
| | - J. L. McCreight
- National Snow and Ice Data Center, Cooperative Institute for Research in Environmental Sciences; University of Colorado; Boulder Colorado USA
| | - M. C. Serreze
- National Snow and Ice Data Center, Cooperative Institute for Research in Environmental Sciences; University of Colorado; Boulder Colorado USA
| | - D. P. Lettenmaier
- Department of Civil and Environmental Engineering; University of Washington; Seattle Washington USA
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35
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White D, Hinzman L, Alessa L, Cassano J, Chambers M, Falkner K, Francis J, Gutowski WJ, Holland M, Holmes RM, Huntington H, Kane D, Kliskey A, Lee C, McClelland J, Peterson B, Rupp TS, Straneo F, Steele M, Woodgate R, Yang D, Yoshikawa K, Zhang T. The arctic freshwater system: Changes and impacts. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jg000353] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Daniel White
- Institute of Northern Engineering; University of Alaska Fairbanks; Fairbanks Alaska USA
| | - Larry Hinzman
- International Arctic Research Center; University of Alaska Fairbanks; Fairbanks Alaska USA
| | - Lilian Alessa
- Resilience and Adaptive Management Group; University of Alaska Anchorage; Anchorage Alaska USA
| | - John Cassano
- Cooperative Institute for Research in Environmental Sciences; University of Colorado; Boulder Colorado USA
| | - Molly Chambers
- Institute of Northern Engineering; University of Alaska Fairbanks; Fairbanks Alaska USA
| | - Kelly Falkner
- College of Oceanic and Atmospheric Science; Oregon State University; Corvallis Oregon USA
| | - Jennifer Francis
- Institute of Marine and Coastal Sciences; Rutgers University; New Brunswick New Jersey USA
| | - William J. Gutowski
- Agronomy, Geological and Atmospheric Sciences Department; Iowa State University; Ames Iowa USA
| | - Marika Holland
- National Center for Atmospheric Research; Boulder Colorado USA
| | - R. Max Holmes
- Woods Hole Research Center; Woods Hole Massachusetts USA
| | | | - Douglas Kane
- Water and Environmental Research Center; University of Alaska Fairbanks; Fairbanks Alaska USA
| | - Andrew Kliskey
- Resilience and Adaptive Management Group; University of Alaska Anchorage; Anchorage Alaska USA
| | - Craig Lee
- Applied Physics Laboratory; University of Washington; Seattle Washington USA
| | - James McClelland
- Marine Science Institute; University of Texas; Port Aransas Texas USA
| | - Bruce Peterson
- Marine Biology Laboratory; Ecosystems Center; Woods Hole Massachusetts USA
| | - T. Scott Rupp
- School of Natural Resources and Agricultural Sciences; University of Alaska Fairbanks; Fairbanks Alaska USA
| | - Fiamma Straneo
- Woods Hole Research Center; Woods Hole Massachusetts USA
| | - Michael Steele
- Applied Physics Laboratory; University of Washington; Seattle Washington USA
| | - Rebecca Woodgate
- Applied Physics Laboratory; University of Washington; Seattle Washington USA
| | - Daqing Yang
- Water and Environmental Research Center; University of Alaska Fairbanks; Fairbanks Alaska USA
| | - Kenji Yoshikawa
- Water and Environmental Research Center; University of Alaska Fairbanks; Fairbanks Alaska USA
| | - Tingjun Zhang
- National Snow and Ice Data Center; University of Colorado; Boulder Colorado USA
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36
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Holland MM, Finnis J, Barrett AP, Serreze MC. Projected changes in Arctic Ocean freshwater budgets. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jg000354] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Joel Finnis
- Department of Atmospheric and Oceanic Sciences; University of Colorado; Boulder Colorado USA
| | - Andrew P. Barrett
- Department of Atmospheric and Oceanic Sciences; University of Colorado; Boulder Colorado USA
| | - Mark C. Serreze
- Department of Atmospheric and Oceanic Sciences; University of Colorado; Boulder Colorado USA
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37
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Affiliation(s)
- John A Church
- CSIRO Marine and Atmospheric Research and Antarctic Climate and Ecosystems CRC, GPO Box 1538, Hobart, Tasmania 7001, Australia.
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38
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Abstract
Oxygen isotope analysis of benthic foraminifera in deep sea cores from the Atlantic and Southern Oceans shows that during the last interglacial period, North Atlantic Deep Water (NADW) was 0.4 degrees +/- 0.2 degrees C warmer than today, whereas Antarctic Bottom Water temperatures were unchanged. Model simulations show that this distribution of deep water temperatures can be explained as a response of the ocean to forcing by high-latitude insolation. The warming of NADW was transferred to the Circumpolar Deep Water, providing additional heat around Antarctica, which may have been responsible for partial melting of the West Antarctic Ice Sheet.
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Affiliation(s)
- J C Duplessy
- Laboratoire des Sciences du Climat et de l'Environnement/Institut Pierre Simon Laplace (LSCE/IPSL), CNRS/Université de Versailles Saint Quentin (CEA/CNRS/UVSQ), Parc du CNRS, 91198 Gif sur Yvette, France.
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39
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Affiliation(s)
- Frank J Millero
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, Florida 33149, USA.
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40
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Schott FA, Brandt P. Circulation and deep water export of the subpolar North Atlantic during the 1990's. OCEAN CIRCULATION: MECHANISMS AND IMPACTS—PAST AND FUTURE CHANGES OF MERIDIONAL OVERTURNING 2007. [DOI: 10.1029/173gm08] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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41
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Serreze MC, Barrett AP, Slater AG, Woodgate RA, Aagaard K, Lammers RB, Steele M, Moritz R, Meredith M, Lee CM. The large-scale freshwater cycle of the Arctic. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jc003424] [Citation(s) in RCA: 424] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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42
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Peterson BJ, McClelland J, Curry R, Holmes RM, Walsh JE, Aagaard K. Trajectory Shifts in the Arctic and Subarctic Freshwater Cycle. Science 2006; 313:1061-6. [PMID: 16931747 DOI: 10.1126/science.1122593] [Citation(s) in RCA: 281] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Manifold changes in the freshwater cycle of high-latitude lands and oceans have been reported in the past few years. A synthesis of these changes in freshwater sources and in ocean freshwater storage illustrates the complementary and synoptic temporal pattern and magnitude of these changes over the past 50 years. Increasing river discharge anomalies and excess net precipitation on the ocean contributed approximately 20,000 cubic kilometers of fresh water to the Arctic and high-latitude North Atlantic oceans from lows in the 1960s to highs in the 1990s. Sea ice attrition provided another approximately 15,000 cubic kilometers, and glacial melt added approximately 2000 cubic kilometers. The sum of anomalous inputs from these freshwater sources matched the amount and rate at which fresh water accumulated in the North Atlantic during much of the period from 1965 through 1995. The changes in freshwater inputs and ocean storage occurred in conjunction with the amplifying North Atlantic Oscillation and rising air temperatures. Fresh water may now be accumulating in the Arctic Ocean and will likely be exported southward if and when the North Atlantic Oscillation enters into a new high phase.
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Affiliation(s)
- Bruce J Peterson
- Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA 02543, USA.
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43
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Moran K, Backman J, Brinkhuis H, Clemens SC, Cronin T, Dickens GR, Eynaud F, Gattacceca J, Jakobsson M, Jordan RW, Kaminski M, King J, Koc N, Krylov A, Martinez N, Matthiessen J, McInroy D, Moore TC, Onodera J, O'Regan M, Pälike H, Rea B, Rio D, Sakamoto T, Smith DC, Stein R, St John K, Suto I, Suzuki N, Takahashi K, Watanabe M, Yamamoto M, Farrell J, Frank M, Kubik P, Jokat W, Kristoffersen Y. The Cenozoic palaeoenvironment of the Arctic Ocean. Nature 2006; 441:601-5. [PMID: 16738653 DOI: 10.1038/nature04800] [Citation(s) in RCA: 404] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2005] [Accepted: 04/13/2006] [Indexed: 11/08/2022]
Abstract
The history of the Arctic Ocean during the Cenozoic era (0-65 million years ago) is largely unknown from direct evidence. Here we present a Cenozoic palaeoceanographic record constructed from >400 m of sediment core from a recent drilling expedition to the Lomonosov ridge in the Arctic Ocean. Our record shows a palaeoenvironmental transition from a warm 'greenhouse' world, during the late Palaeocene and early Eocene epochs, to a colder 'icehouse' world influenced by sea ice and icebergs from the middle Eocene epoch to the present. For the most recent approximately 14 Myr, we find sedimentation rates of 1-2 cm per thousand years, in stark contrast to the substantially lower rates proposed in earlier studies; this record of the Neogene reveals cooling of the Arctic that was synchronous with the expansion of Greenland ice (approximately 3.2 Myr ago) and East Antarctic ice (approximately 14 Myr ago). We find evidence for the first occurrence of ice-rafted debris in the middle Eocene epoch (approximately 45 Myr ago), some 35 Myr earlier than previously thought; fresh surface waters were present at approximately 49 Myr ago, before the onset of ice-rafted debris. Also, the temperatures of surface waters during the Palaeocene/Eocene thermal maximum (approximately 55 Myr ago) appear to have been substantially warmer than previously estimated. The revised timing of the earliest Arctic cooling events coincides with those from Antarctica, supporting arguments for bipolar symmetry in climate change.
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Affiliation(s)
- Kathryn Moran
- Graduate School of Oceanography & Department of Ocean Engineering, University of Rhode Island, Narragansett, Rhode Island 02882, USA.
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Yin J, Schlesinger ME, Andronova NG, Malyshev S, Li B. Is a shutdown of the thermohaline circulation irreversible? ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jd006562] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Hátún H, Sandø AB, Drange H, Hansen B, Valdimarsson H. Influence of the Atlantic Subpolar Gyre on the Thermohaline Circulation. Science 2005; 309:1841-4. [PMID: 16166513 DOI: 10.1126/science.1114777] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
During the past decade, record-high salinities have been observed in the Atlantic Inflow to the Nordic Seas and the Arctic Ocean, which feeds the North Atlantic thermohaline circulation (THC). This may counteract the observed long-term increase in freshwater supply to the area and tend to stabilize the North Atlantic THC. Here we show that the salinity of the Atlantic Inflow is tightly linked to the dynamics of the North Atlantic subpolar gyre circulation. Therefore, when assessing the future of the North Atlantic THC, it is essential that the dynamics of the subpolar gyre and its influence on the salinity are taken into account.
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Affiliation(s)
- Hjálmar Hátún
- Faroese Fisheries Laboratory, Box 3051, FO-110, Tórshavn, Faroe Islands.
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Hogan J. Ocean freshens up. Nature 2005. [DOI: 10.1038/news050613-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Overpeck JT, Sturm M, Francis JA, Perovich DK, Serreze MC, Benner R, Carmack EC, Chapin FS, Gerlach SC, Hamilton LC, Hinzman LD, Holland M, Huntington HP, Key JR, Lloyd AH, McDonald GM, McFadden J, Noone D, Prowse TD, Schlosser P, Vörösmarty C. Arctic system on trajectory to new, seasonally ice-free state. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2005eo340001] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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