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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Warming amplification over the Arctic Pole and Third Pole: Trends, mechanisms and consequences

Earth-Science Reviews, Journal Year: 2021, Volume and Issue: 217, P. 103625 - 103625

Published: April 14, 2021

Language: Английский

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Improved Performance of ERA5 in Arctic Gateway Relative to Four Global Atmospheric Reanalyses

Geophysical Research Letters, Journal Year: 2019, Volume and Issue: 46(11), P. 6138 - 6147

Published: May 23, 2019

Abstract Here we evaluate five atmospheric reanalyses in an Arctic gateway during late summer. The include ERA5, ERA‐Interim, Japanese 55 year Re‐Analysis (JRA‐55), Climate Forecasting System Reanalysis‐version 2 (CFSv2), and Modern Era Retrospective analysis for Research Applications‐version (MERRA‐2). We use observations from 50 radiosondes launched the Fram Strait around 79‐80°N, between 25 August 11 September 2017. Crucially, data 27 were not transmitted to Global Telecommunications therefore assimilated into any reanalysis. In most reanalyses, magnitude of wind speed humidity errors is similar profiles with without assimilation. cases assimilation, correlation coefficients ( R ) exceed 0.88 temperature, speed, specific humidity, all reanalyses. Overall, newly released ERA5 has higher than other as well smaller biases root‐mean‐square errors, three variables. largest improvements identified are its representation field, temperature over warm water.

Language: Английский

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Comparison of ERA5 and ERA-Interim near-surface air temperature, snowfall and precipitation over Arctic sea ice: effects on sea ice thermodynamics and evolution

˜The œcryosphere, Journal Year: 2019, Volume and Issue: 13(6), P. 1661 - 1679

Published: June 14, 2019

Abstract. Rapid changes are occurring in the Arctic, including a reduction sea ice thickness and coverage shift towards younger thinner ice. Snow models often used to study these ongoing typically forced by atmospheric reanalyses absence of observations. ERA5 is new global reanalysis that will replace widely ERA-Interim (ERA-I). In this study, we compare 2 m air temperature (T2M), snowfall (SF) total precipitation (TP) from ERA-I ERA5, evaluate products using buoy observations Arctic for years 2010 2016. We further assess how biases can influence snow evolution when force thermodynamic model. find generally warmer than winter spring (0–1.2 ∘C), but colder summer autumn (0–0.6 ∘C) over Both have warm bias relative The smaller season, larger cold especially T2M below −25 ∘C Atlantic Pacific sectors. Interestingly, on average 3.4 5.4 (daily mean), respectively, lower ∘C. TP SF along trajectories consistently higher ERA-I. Over ice, less 10 mm water equivalent (SWE) greater any seasons, while be 50 SWE season. largest increase annual (40–100 mm) (100–200 occurs sector. ratio ERA-I, 0.6 0.8 trajectories. Thus, substantial anomalous rainfall reduced autumn. Simulations with 1-D model demonstrate acts reduce growth. results thicker snowpack allows heat loss atmosphere. compared result at end growth season ERA5; however effect small during freezing period.

Language: Английский

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Evaluation of Six Atmospheric Reanalyses over Arctic Sea Ice from Winter to Early Summer

Journal of Climate, Journal Year: 2019, Volume and Issue: 32(14), P. 4121 - 4143

Published: May 9, 2019

Abstract This study evaluates the performance of six atmospheric reanalyses (ERA-Interim, ERA5, JRA-55, CFSv2, MERRA-2, and ASRv2) over Arctic sea ice from winter to early summer. The are evaluated using observations Norwegian Young Sea Ice campaign (N-ICE2015), a 5-month drift in pack north Svalbard. N-ICE2015 include surface meteorology, vertical profiles radiosondes, as well radiative turbulent heat fluxes. simulate analysis variables throughout campaign, but have difficulties with most forecast variables. Wintertime (January–March) correlation coefficients between above 0.90 for pressure, 2-m temperature, total column water vapor, downward longwave flux. However, all positive wintertime temperature bias, ranging 1° 4°C, negative (i.e., upward) net bias 3–19 W m −2 . These biases associated poorly represented inversions largest during cold-stable periods. Notably, recent ERA5 ASRv2 datasets some biases, respectively. During spring (April–May), fail observed persistent cloud layers. Therefore they overestimate shortwave flux (5–79 ) underestimate (8–38 ). Promisingly, provides best estimates fluxes summer, suggesting improved forecasting cover. All exhibit large (upward) residual winter, (downward) Turbulent simulated seasons.

Language: Английский

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Extreme weather and climate events in northern areas: A review

Earth-Science Reviews, Journal Year: 2020, Volume and Issue: 209, P. 103324 - 103324

Published: Aug. 12, 2020

The greatest impacts of climate change on ecosystems, wildlife and humans often arise from extreme events rather than changes in climatic means. Northern high latitudes, including the Arctic, experience a variety climate-related events, yet there has been little attempt to synthesize information this region. This review surveys work various types northern addressing (1) evidence for variations based analyses recent historical data (2) projected primarily studies utilizing global models. survey weather includes temperature, precipitation, snow, freezing rain, atmospheric blocking, cyclones, wind. also cryospheric biophysical impacts: sea ice rapid loss Greenland Ice Sheet melt, floods, drought, wildfire, coastal erosion, terrestrial marine ecosystems. Temperature rank at end spectra confidence future change, while flooding cyclones lower end. Research priorities identified basis include greater use high-resolution models observing system enhancements that target events. There is need further attribution, ecosystems humans, thresholds or tipping points may be triggered by latitudes.

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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Faster Atlantic currents drive poleward expansion of temperate phytoplankton in the Arctic Ocean

Nature Communications, Journal Year: 2020, Volume and Issue: 11(1)

Published: April 6, 2020

Abstract The Arctic marine biome, shrinking with increasing temperature and receding sea-ice cover, is tightly connected to lower latitudes through the North Atlantic. By flowing northward European Corridor (the main gateway where 80% of in- outflow takes place), Atlantic Waters transport most ocean heat, but also nutrients planktonic organisms toward Ocean. Using satellite-derived altimetry observations, we reveal an increase, up two-fold, in current surface velocities over last 24 years. More importantly, show evidence that its variability shape spatial distribution coccolithophore Emiliania huxleyi ( Ehux ), a tracer for temperate ecosystems. We further demonstrate bio-advection, rather than water as previously assumed, major mechanism responsible recent poleward intrusions southern species like . Our findings confirm biological physical “Atlantification” Ocean potential alterations food web biogeochemical cycles.

Language: Английский

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Exceptional warming over the Barents area

Scientific Reports, Journal Year: 2022, Volume and Issue: 12(1)

Published: June 15, 2022

In recent decades, surface air temperature (SAT) data from Global reanalyses points to maximum warming over the northern Barents area. However, a scarcity of observations hampers confidence in this Arctic hotspot region. Here, we study past 20-40 years based on new available SAT and quality controlled comprehensive dataset archipelagos Sea. We identify statistically significant record-high annual up 2.7 °C per decade, with autumn 4.0 decade. Our results are compared most global regional reanalysis sets, as well remote sensing records sea ice concentration (SIC), (SST) high-resolution charts. The pattern is primarily consistent reductions cover confirms general spatial temporal patterns represented by reanalyses. our findings suggest even stronger rate SIC-SAT relation than was known region until now.

Language: Английский

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A Lagrangian Snow‐Evolution System for Sea‐Ice Applications (SnowModel‐LG): Part I—Model Description

Journal of Geophysical Research Oceans, Journal Year: 2020, Volume and Issue: 125(10)

Published: Aug. 7, 2020

Abstract A Lagrangian snow‐evolution model (SnowModel‐LG) was used to produce daily, pan‐Arctic, snow‐on‐sea‐ice, snow property distributions on a 25 × 25‐km grid, from 1 August 1980 through 31 July 2018 (38 years). The forced with NASA's Modern Era Retrospective‐Analysis for Research and Applications‐Version 2 (MERRA‐2) European Centre Medium‐Range Weather Forecasts (ECMWF) ReAnalysis‐5th Generation (ERA5) atmospheric reanalyses, National Snow Ice Data Center (NSIDC) sea ice parcel concentration trajectory data sets (approximately 61,000, 14 14‐km parcels). simulations performed full surface internal energy mass balances within multilayer snowpack evolution system. Processes features accounted included rainfall, snowfall, sublimation static‐surfaces blowing‐snow, melt, density evolution, temperature profiles, transfers the snowpack, superimposed ice, dynamics. produced horizontal spatial structures that likely exist in natural system but have not been revealed previous studies spanning these temporal domains. Blowing‐snow made significant contribution budget. layer minimal decreased over last four decades. carryover next accumulation season sensitive melt‐season forcing (e.g., average summer melt period 3 weeks or 50% longer ERA5 than MERRA‐2 forcing). Observed dynamics controlled age (in days), exerted first‐order control evolution.

Language: Английский

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