Changing state of Arctic sea ice across all seasons

Environmental Research Letters, Journal Year: 2018, Volume and Issue: 13(10), P. 103001 - 103001

Published: Sept. 3, 2018

The decline in the floating sea ice cover Arctic is one of most striking manifestations climate change. In this review, we examine ongoing loss across all seasons. Our analysis based on satellite retrievals, atmospheric reanalysis, climate-model simulations and a literature review. We find that relative to 1981–2010 reference period, recent anomalies spring winter coverage have been more significant than any observed drop summer extent (SIE) throughout period. For example, SIE May November 2016 was almost four standard deviations below these months. Decadal during months has accelerated from −2.4 %/decade 1979 1999 −3.4%/decade 2000 onwards. also regional for given region, seasonal larger closer region outer edge cover. Finally, months, identify robust linear relationship between pan-Arctic total anthropogenic CO2 emissions. annual cycle per ton emissions ranges slightly above 1 m2 3 summer. Based extrapolation trends, Ocean will become sea-ice free August September an additional 800 ± 300 Gt emissions, while it becomes July October 1400

Language: Английский

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Changing State of the Climate System

Cambridge University Press eBooks, Journal Year: 2023, Volume and Issue: unknown, P. 287 - 422

Published: June 29, 2023

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Language: Английский

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The polar regions in a 2°C warmer world

Science Advances, Journal Year: 2019, Volume and Issue: 5(12)

Published: Dec. 5, 2019

Over the past decade, Arctic has warmed by 0.75°C, far outpacing global average, while Antarctic temperatures have remained comparatively stable. As Earth approaches 2°C warming, and may reach 4°C mean annual 7°C 3°C winter respectively. Expected consequences of increased warming include ongoing loss land sea ice, threats to wildlife traditional human livelihoods, methane emissions, extreme weather at lower latitudes. With low biodiversity, ecosystems be vulnerable state shifts species invasions. Land ice in both regions will contribute substantially level rise, with up 3 m rise possible if certain thresholds are crossed. Mitigation efforts can slow or reduce but without them northern high latitude accelerate next two four decades. International cooperation crucial foreseeing adapting expected changes.

Language: Английский

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Version 2 of the EUMETSAT OSI SAF and ESA CCI sea-ice concentration climate data records

˜The œcryosphere, Journal Year: 2019, Volume and Issue: 13(1), P. 49 - 78

Published: Jan. 9, 2019

Abstract. We introduce the OSI-450, SICCI-25km and SICCI-50km climate data records of gridded global sea-ice concentration. These three are derived from passive microwave satellite offer distinct advantages compared to existing records: first, all provide quantitative information on uncertainty possibly applied filtering at every grid point time step. Second, they based dynamic tie points, which capture evolution surface characteristics ice cover accommodate potential calibration differences between missions. Third, produced in context sustained services offering committed extension, documentation, traceability, user support. The differ underlying (SMMR & SSM/I SSMIS or AMSR-E AMSR2), imaging frequency channels (37 GHz either 6 19 GHz), their horizontal resolution (25 50 km), period cover. algorithms an evaluation. find that compare well with independent estimates concentration both regions very high low hence trust these will prove helpful for a better understanding Earth's

Language: Английский

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The Arctic's sea ice cover: trends, variability, predictability, and comparisons to the Antarctic

Annals of the New York Academy of Sciences, Journal Year: 2018, Volume and Issue: 1436(1), P. 36 - 53

Published: May 28, 2018

Abstract As assessed over the period of satellite observations, October 1978 to present, there are downward linear trends in Arctic sea ice extent for all months, largest at end melt season September. The cover is also thinning. Downward and thickness have been accompanied by pronounced interannual multiyear variability, forced both atmosphere ocean. thins, its response atmospheric oceanic forcing may be changing. In support a busier Arctic, growing need predict conditions on variety time space scales. A major challenge providing seasonal scale predictions 7–10 days limit numerical weather prediction. While seasonally ice‐free Ocean likely well within this century, much uncertainty timing. This reflects differences climate model structure, unknown evolution anthropogenic forcing, natural variability. sharp contrast Antarctic extent, while highly variable, has increased slightly observations. reasons different behavior remain resolved, but responses changing circulation patterns appear play strong role.

Language: Английский

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Variability and trends in the Arctic Sea ice cover: Results from different techniques

Journal of Geophysical Research Oceans, Journal Year: 2017, Volume and Issue: 122(8), P. 6883 - 6900

Published: July 13, 2017

Abstract Variability and trend studies of sea ice in the Arctic have been conducted using products derived from same raw passive microwave data but by different groups algorithms. This study provides consistency assessment four leading products, namely, Goddard Bootstrap (SB2), NASA Team (NT1), EUMETSAT Ocean Sea Ice Satellite Application Facility (OSI‐SAF 1.2), Hadley HadISST 2.2 evaluating variability trends cover. All provide generally similar patterns significant disagreements concentration distributions especially marginal zone adjacent regions winter meltponded areas summer. The discrepancies are primarily due to ways techniques account for occurrences new meltponding. However, results show that consistent representation state NT1 usually highest lowest monthly extents, respectively. also extent area at −3.88%/decade −4.37%/decade, respectively, compared an average −4.36%/decade −4.57%/decade all four. Trend maps spatial distribution with largest negative occurring Kara/Barents Beaufort regions, where has retreating fastest. good agreement updated strong confidence quantification rate decline

Language: Английский

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Assessment of Sea Ice Extent in CMIP6 With Comparison to Observations and CMIP5

Geophysical Research Letters, Journal Year: 2020, Volume and Issue: 47(9)

Published: April 23, 2020

Abstract Both the Arctic and Antarctic sea ice extents (SIEs) from 44 coupled models in Coupled Model Intercomparison Project Phase 6 (CMIP6) are evaluated by comparing them with observations CMIP5 results. The CMIP6 multimodel mean can adequately reproduce seasonal cycles of both SIE. observed September SIE declining trend (−0.82 ± 0.18 million km 2 per decade) between 1979 2014 is slightly underestimated (−0.70 0.06 decade). weak but significant upward not captured, which was an issue already phase. Compared models, have lower intermodel spreads values trends, although their biases relatively larger. did new summer tendencies after 2000, including faster decline larger interannual variability

Language: Английский

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Antarctic Futures: An Assessment of Climate-Driven Changes in Ecosystem Structure, Function, and Service Provisioning in the Southern Ocean

Annual Review of Marine Science, Journal Year: 2019, Volume and Issue: 12(1), P. 87 - 120

Published: July 24, 2019

In this article, we analyze the impacts of climate change on Antarctic marine ecosystems. Observations demonstrate large-scale changes in physical variables and circulation Southern Ocean driven by warming, stratospheric ozone depletion, a positive Annular Mode. Alterations environment are driving through all levels food webs, which differ regionally. The distributions key species, such as krill, also changing. Differential responses among predators reflect differences species ecology. biodiversity will likely vary for different communities depend range. Coastal those sub-Antarctic islands, especially range-restricted endemic communities, suffer greatest negative consequences change. Simultaneously, ecosystem services increase. Such decoupling require consideration management human activities fishing

Language: Английский

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An enhancement to sea ice motion and age products at the National Snow and Ice Data Center (NSIDC)

˜The œcryosphere, Journal Year: 2020, Volume and Issue: 14(5), P. 1519 - 1536

Published: May 7, 2020

Abstract. A new version of sea ice motion and age products includes several significant upgrades in processing, corrects known issues with the previous version, updates time series through 2018, regular planned for future. First, we provide a history these NASA distributed at National Snow Ice Data Center. Then discuss improvements to algorithms, validation results (Version 4) older versions, intercompare two. While Version 4 algorithm changes were significant, impact on is relatively minor, particularly more recent years. The reduce biases by ∼ 0.01 0.02 cm s−1 error standard deviations 0.3 s−1. Overall, speed increased over 3 0.5 2.0 most series. shows higher positive trend Arctic 0.21 per decade compared 0.13 3. estimates indicates than 3, especially earlier record, but similar trends toward less multiyear ice. Changes derived from product show shift cover, pack high concentration cover dominated first-year ice, which susceptible summer melt. We also observe an increase ≥ 30 years, has been shown other studies anticipated annual decrease extent.

Language: Английский

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Conditions leading to the unprecedented low Antarctic sea ice extent during the 2016 austral spring season

Geophysical Research Letters, Journal Year: 2017, Volume and Issue: 44(17), P. 9008 - 9019

Published: Aug. 25, 2017

Abstract The 2016 austral spring was characterized by the lowest Southern Hemisphere (SH) sea ice extent seen in satellite record (1979 to present) and coincided with anomalously warm surface waters surrounding most of Antarctica. We show that two distinct processes contributed this event: First, extreme El Niño event peaking December–February 2015/2016 pronounced extratropical SH temperature anomalies eastern Ross, Amundsen, Bellingshausen Seas persisted part until following spring. Second, internal unforced atmospheric variability Annular Mode promoted exceptional low November–December 2016. These results suggest a combination tropically forced unprecedented decline during spring, on top background slow changes expected from greenhouse gas ozone forcing.

Language: Английский

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