Past and future ocean warming

Nature Reviews Earth & Environment, Journal Year: 2022, Volume and Issue: 3(11), P. 776 - 794

Published: Oct. 18, 2022

Language: Английский

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A Synthesis of the Upper Arctic Ocean Circulation During 2000–2019: Understanding the Roles of Wind Forcing and Sea Ice Decline

Frontiers in Marine Science, Journal Year: 2022, Volume and Issue: 9

Published: May 18, 2022

Major changes have occurred in the Arctic Ocean during 2000–2019, including unprecedented spin-up of Beaufort Gyre and emergence Atlantification eastern Eurasian Basin. We explored main drivers for these by synthesizing numerical simulations observations this paper. The atmospheric circulation was unusual some years period, with strongly negative wind curl over Canada However, wind-driven would been much weaker had it not sea ice decline. decline only fed ocean meltwater, but also made other freshwater components more available to through mediating surface stress. This dynamical effect shifting from Basin towards Amerasian resulted Basin, which is characterized halocline salinification uplift boundary between Atlantic Water layer. Contemporarily, caused a strong warming trend Empirical Orthogonal Function (EOF) analysis annual height period reveals that first two modes upper active centers associated Oscillation High variability, respectively. In presence EOFs can better distinguish variability driven modes. Therefore, major past decades are indicators climate change as retreat. Our synthesis could help assess how might future climate.

Language: Английский

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Dansgaard–Oeschger events in climate models: review and baseline Marine Isotope Stage 3 (MIS3) protocol

Climate of the past, Journal Year: 2023, Volume and Issue: 19(5), P. 915 - 942

Published: May 8, 2023

Abstract. Dansgaard–Oeschger (D–O) events, millennial-scale climate oscillations between stadial and interstadial conditions (of up to 10–15 ∘C in amplitude at high northern latitudes), occurred throughout the Marine Isotope Stage 3 (MIS3; 27.8–59.4 ka) period. The modelling community now has not been able answer question of whether our models are too stable simulate D–O events. To address this, this paper lays ground-work for a MIS3 protocol general circulation which used International Panel Climate Change (IPCC) assessments. We review following: terminology, progress on simulating events these IPCC-class (processes published examples), evidence about boundary under occur. find that no model exhibits D–O-like behaviour pre-industrial conditions. Some, but all, exhibit and/or full glacial Greenhouse gases ice sheet configurations crucial. However most have run simulations long enough duration be sure show behaviour, either or states. propose baseline 34 ka, features low obliquity values, medium greenhouse gas intermediate configuration, suggests conducive models. also provide second freshwater (Heinrich-event-preconditioned) experiment, since previous work variant may helpful preconditioning state is This provides groups investigating with common framework, aimed (1) maximising chance occurrence simulations, (2) allowing more precise model–data evaluation, (3) providing an adequate central point modellers explore stability.

Language: Английский

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Pervasive glacier retreats across Svalbard from 1985 to 2023

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: Jan. 15, 2025

Abstract A major uncertainty in predicting the behaviour of marine-terminating glaciers is ice dynamics driven by non-linear calving front retreat, which poorly understood and modelled. Using 124919 positions for 149 Svalbard from 1985 to 2023, generated with deep learning, we identify pervasive retreats non-surging over past 38 years. We observe widespread seasonal cycles position half glaciers. At timescale, peak retreat rates exhibit a several-month phase lag, changes on west coast occurring before those east coast, coincident regional ocean warming. This spatial variability patterns linked different timings warm water inflow West Spitsbergen Current, demonstrating dominant role ice-ocean interaction changes. The interannual shows strong sensitivity both atmospheric oceanic warming, immediate responses large air temperature anomalies 2016 2019, likely blocking that can influence extreme variability. With more frequent continued future will intensify, leading significant glacier mass loss.

Language: Английский

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Greening of Svalbard in the twentieth century driven by sea ice loss and glaciers retreat

Communications Earth & Environment, Journal Year: 2025, Volume and Issue: 6(1)

Published: Jan. 16, 2025

The greening of previously barren landscapes in the Arctic is one most relevant responses terrestrial ecosystem to climate change. Analyses satellite data (available since ~1980) have revealed a widespread tundra advance consistent with recent global warming, but length insufficient resolve long-term variability and precise timing onset. Here, we measured plant-derived biomarkers from an fjord sediment core as proxies for reconstructing past changes vegetation during transition Little Ice Age modern warming. Our findings rapid expansion beginning twentieth century, largely coinciding decline summer sea ice extent glacier retreat. trend inferred biomarker analysis peaked significantly late 1990s, along shift community towards more mature successional stage. Most these signals were biomolecular fingerprints vascular plant species that are adapted warmer conditions widely expanded proglacial areas decades. results suggest fjords may occurred earlier than thought, improving our mechanistic understanding vegetation-climate-cryosphere interactions will shape under future warming projections. tundra's century has been driven by retreat, according Svalbard.

Language: Английский

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Role of Atlantification in Enhanced Primary Productivity in the Barents Sea

Earth s Future, Journal Year: 2024, Volume and Issue: 12(1)

Published: Jan. 1, 2024

Abstract Recent changes in the Arctic sea‐ice are strongly influenced by recent increase heat transport from vigorous Atlantic inflows, so‐called Atlantification. This Atlantification can induce physical and ecological near gateway. Here, we used observational data sets 26 Earth system models to estimate water intrusion, firstly suggest impact of on marine productivity Barents Sea a warming climate, especially boreal spring. In across Opening (BSO) is projected be enhanced (45.5 ± 34.9 TW) end 21st century compared present climate. poleward intrusion likely with largest spring (70%). Atlantification‐induced states—ocean temperature, circulations, stratification, sea‐ice. Based inter‐model analyses, estimated that explain approximately 26% Sea. Thus, critical for future biological states over Ocean.

Language: Английский

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Climate extremes in Svalbard over the last two millennia are linked to atmospheric blocking

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: June 3, 2024

Abstract Arctic precipitation in the form of rain is forecast to become more prevalent a warmer world but with seasonal and interannual changes modulated by natural modes variability. Experiencing rapid hydroclimatic Arctic, Svalbard serves as an ideal study location due its exposure oceanic atmospheric variability North Atlantic region. Here we use climate data from paleoproxies, observations, model demonstrate that wet warm extremes over last two millennia are linked presence blocking regimes Scandinavia Ural mountain Rainfall episodes lead deposition coarse sediment particles high levels calcium Linnévatnet, lake southwest Svalbard, coarsest sediments consistently deposited during events. A unique annually resolved record Linnévatnet confirms this linkage has been persistent past 2000 years. Our also shows millennial-scale decline ended around middle 19th century, followed several unprecedented extreme events recent As warming continues sea ice recedes, future floods will intense Scandinavian blocking.

Language: Английский

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A seasonally ice-free Arctic Ocean during the Last Interglacial

Nature Geoscience, Journal Year: 2023, Volume and Issue: 16(8), P. 723 - 729

Published: Aug. 1, 2023

Abstract The extent and seasonality of Arctic sea ice during the Last Interglacial (129,000 to 115,000 years before present) is poorly known. Sediment-based reconstructions have suggested extensive cover in summer, while climate model outputs indicate year-round conditions Ocean ranging from free fully covered. Here we use microfossil records across central show that sea-ice was substantially reduced summers were probably free. evidence comes high abundances subpolar planktic foraminifera Turborotalita quinqueloba five newly analysed cores. northern occurrence this species incompatible with perennial ice, which would be associated a thick, low-salinity surface water. Instead , T. ’s ecological preference implies largely ice-free waters seasonally elevated levels primary productivity. In modern ocean, thrives Fram Strait–Barents Sea ‘Arctic–Atlantic gateway’ region, implying necessary Atlantic Ocean-sourced water masses shoaled towards Interglacial. This process reflects ongoing Atlantification Ocean, currently restricted Eurasian Basin. Our results establish as prime analogue for studying expected occur century.

Language: Английский

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Winners and Losers of Atlantification: The Degree of Ocean Warming Affects the Structure of Arctic Microbial Communities

Genes, Journal Year: 2023, Volume and Issue: 14(3), P. 623 - 623

Published: March 1, 2023

Arctic microbial communities (i.e., protists and bacteria) are increasingly subjected to an intrusion of new species via Atlantification uncertain degree ocean warming. As differ in adaptive traits, these oceanic conditions may lead compositional changes with functional implications for the ecosystem. In June 2021, we incubated water from western Fram Strait at three temperatures (2 °C, 6 9 °C), mimicking current potential future properties Ocean. Our results show that increasing temperature °C only minorly affects community, while increase significantly lowers diversity shifts composition. A higher relative abundance large hetero- mixotrophic was observed 2 compared a intermediate-sized temperate diatoms °C. The differences led chlorophyll a:POC ratio, but C:N ratio remained similar. contradict common assumption smaller organisms heterotrophs favored under warming strongly indicate thermal limit between many species. Consequently, magnitude is crucial factor community reorganization ensuing ecological consequences

Language: Английский

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Shallow-Water Bryozoan Communities in a Glacier Fjord of West Svalbard, Norway: Species Composition and Effects of Environmental Factors

Biology, Journal Year: 2023, Volume and Issue: 12(2), P. 185 - 185

Published: Jan. 26, 2023

Despite significant research efforts focused on benthic assemblages in West Spitsbergen, there is a lack of knowledge regarding the shallow water bryozoan communities Grønfjorden, glacier fjord belonging to Isfjorden system, Norway. Here, we studied species composition, richness, distribution, and biomass bryozoans intertidal upper subtidal zones Grønfjorden summer. We found 62 species, among which Celleporella hyalina (Linnaeus, 1767), Harmeria scutulata (Busk, 1855), Tegella arctica (d’Orbigny, 1853) were most prevalent while highest contributions total registered for Eucratea loricata 1853), Tricellaria gracilis (Van Beneden, 1848), Turbicellepora incrassata (Lamarck, 1816), ternata (Ellis Solander, 1786). Alpha-diversity varied from 1 50 averaging 15.1 ± 2.6 species. Bryozoan ranged 0.008 10.758 g m−2 with mean value 2.67 being lower than central northern parts Barents Sea. For first time, presence circumpolar Amathia Svalbard waters probably as result stronger advection Atlantic into fjord. Cluster analysis revealed two groups, mainly composed stations colder warmer waters. A relatively high proportion outlying reflected habitat heterogeneity Grønfjorden. Redundancy indicated that diversity strongly negatively associated temperature. positive relationship was between proportional contribution macrophytes pool substrates. Our study provides reference point further monitoring changing marine ecosystems at latitudes.

Language: Английский

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