scholarly journals Capturing How Fast the Arctic Ocean Is Gaining Fresh Water

Eos ◽  
2021 ◽  
Vol 102 ◽  
Author(s):  
Sarah Stanley
Keyword(s):  
Arctic Ocean ◽  
Fresh Water ◽  
Surface Waters ◽  
The Arctic ◽  
The Arctic Ocean ◽  
Arctic Surface

A new analysis suggests that models do not accurately capture how fresh Arctic surface waters mix with deeper waters, contributing to underestimation of Arctic surface freshening.

scholarly journals Impact of rapid sea-ice reduction in the Arctic Ocean on the rate of ocean acidification

2011 ◽  
Vol 8 (5) ◽  
pp. 10617-10644
Author(s):  
A. Yamamoto ◽  
M. Kawamiya ◽  
A. Ishida ◽  
Y. Yamanaka ◽  
S. Watanabe
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Surface Waters ◽  
Co2 Concentration ◽  
The Arctic ◽  
Saturation State ◽  
Aragonite Saturation ◽  
The Arctic Ocean ◽  
Arctic Surface ◽  
Sea Ice Reduction

Abstract. The largest pH decline and widespread undersaturation with respect to aragonite in this century due to uptake of anthropogenic carbon dioxide in the Arctic Ocean have been projected. The reductions in pH and aragonite saturation state have been caused primarily by an increase in the concentration of atmospheric carbon dioxide. However, in a previous study, simulations with and without warming showed that these reductions in the Arctic Ocean also advances due to the melting of sea ice caused by global warming. Therefore, future projections of pH and aragonite saturation in the Arctic Ocean will be affected by how rapidly the reduction in sea ice occurs. In this study, the impact of sea-ice reduction rate on projected pH and aragonite saturation state in the Arctic surface waters was investigated. Reductions in pH and aragonite saturation were calculated from the outputs of two versions of an earth system model (ESM) with different sea-ice reduction rates under similar CO2 emission scenarios. The newer model version projects that Arctic summer ice-free condition will be achieved by the year 2040, and the older version predicts ice-free condition by 2090. The Arctic surface water was projected to be undersaturated with respect to aragonite in the annual mean when atmospheric CO2 concentration reached 480 (550) ppm in year 2040 (2048) in new (old) version. At an atmospheric CO2 concentration of 520 ppm, the maximum differences in pH and aragonite saturation state between the two versions were 0.08 and 0.15, respectively. The analysis showed that the decreases in pH and aragonite saturation state due to rapid sea-ice reduction were caused by increases in both CO2 uptake and freshwater input. Thus, the reductions in pH and aragonite saturation state in the Arctic surface waters are significantly affected by the difference in future projections for sea-ice reduction rate. The critical CO2 concentration, at which the Arctic surface waters become undersaturated with respect to aragonite on annual mean bias, would be lower by 70 ppm in the version with the rapid sea-ice reduction.

scholarly journals Ice Lithologies and Structure of Ice Island Arlis II

1964 ◽  
Vol 5 (37) ◽  
pp. 17-38 ◽  
Author(s):  
David D. Smith
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Fresh Water ◽  
Structural Features ◽  
The Arctic ◽  
Glacial Ice ◽  
Water Ice ◽  
Central Block ◽  
The Arctic Ocean

AbstractIce island ARLIS II, which is adrift in the Arctic Ocean, is a 1.3 km. wide and 3.8 km. long fragment of shelf ice 12–25 m. thick, which preserves several structural features heretofore undescribed in ice. The island is composed of an irregular central block of foliated, locally debris-rich, grey glacial ice bordered in part by extensive areas of stratified bluish sea ice. The central block contains a series of narrow, elongate, sub-parallel dike-like septa of massive fresh-water ice and a large tongue-like body of tightly folded, coarse banded ice. Both the septa and the tongue cut across the foliation and debris zones of the grey ice.The margins of the central block are penetrated by a series of elongate, crudely wedge-shaped re-entrants occupied by salients of bluish sea ice. Two broad, arch-like plunging anticlines deform the stratified sea ice along one margin of the block.The foliation and debris zones in the glacial ice are relict features inherited from the source glacier. The septa formed as crevasse and basal fracture fills. Salients represent fills formed in the irregular re-entrants along the margins of the glacial ice mass. The tongue of tightly folded, banded ice represents an earlier generation salient deformed by compressive forces as the fill built up. The broad anticlines are apparently the result of warping in response to differential ablation but the small, tight plunging folds on their noses and limbs are probably the result of compressive forces.

Dissolved Neodymium Isotopes Trace Origin and Spatiotemporal Evolution of Modern Arctic Sea Ice

2020 ◽  
Author(s):  
Georgi Laukert ◽  
Dorothea Bauch ◽  
Ilka Peeken ◽  
Thomas Krumpen ◽  
Kirstin Werner ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Surface Waters ◽  
Ice Cores ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Spatiotemporal Evolution ◽  
Arctic Sea ◽  
The Arctic Ocean ◽  
Ice Floes

<p>The lifetime and thickness of Arctic sea ice have markedly decreased in the recent past. This affects Arctic marine ecosystems and the biological pump, given that sea ice acts as platform and transport medium of marine and atmospheric nutrients. At the same time sea ice reduces light penetration to the Arctic Ocean and restricts ocean/atmosphere exchange. In order to understand the ongoing changes and their implications, reconstructions of source regions and drift trajectories of Arctic sea ice are imperative. Automated ice tracking approaches based on satellite-derived sea-ice motion products (e.g. ICETrack) currently perform well in dense ice fields, but provide limited information at the ice edge or in poorly ice-covered areas. Radiogenic neodymium (Nd) isotopes (ε<sub>Nd</sub>) have the potential to serve as a chemical tracer of sea-ice provenance and thus may provide information beyond what can be expected from satellite-based assessments. This potential results from pronounced ε<sub>Nd</sub> differences between the distinct marine and riverine sources, which feed the surface waters of the different sea-ice formation regions. We present the first dissolved (< 0.45 µm) Nd isotope and concentration data obtained from optically clean Arctic first- and multi-year sea ice (ice cores) collected from different ice floes across the Fram Strait during the RV POLARSTERN cruise PS85 in 2014. Our data confirm the preservation of the seawater ε<sub>Nd</sub>signatures in sea ice despite low Nd concentrations (on average ~ 6 pmol/kg) resulting from efficient brine rejection. The large range in ε<sub>Nd</sub> signatures (~ -10 to -30) mirrors that of surface waters in various parts of the Arctic Ocean, indicating that differences between ice floes but also between various sections in an individual ice core reflect the origin and evolution of the sea ice over time. Most ice cores have ε<sub>Nd</sub> signatures of around -10, suggesting that the sea ice was formed in well-mixed waters in the central Arctic Ocean and transported directly to the Fram Strait via the Transpolar Drift. Some ice cores, however, also revealed highly unradiogenic signatures (ε<sub>Nd</sub> < ~ -15) in their youngest (bottom) sections, which we attribute to incorporation of meltwater from Greenland into newly grown sea ice layers. Our new approach facilitates the reconstruction of the origin and spatiotemporal evolution of isolated sea-ice floes in the future Arctic.</p>

scholarly journals Ice Lithologies and Structure of Ice Island Arlis II

1964 ◽  
Vol 5 (37) ◽  
pp. 17-38 ◽  
Author(s):  
David D. Smith
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Fresh Water ◽  
Structural Features ◽  
The Arctic ◽  
Glacial Ice ◽  
Water Ice ◽  
Central Block ◽  
The Arctic Ocean

Abstract Ice island ARLIS II, which is adrift in the Arctic Ocean, is a 1.3 km. wide and 3.8 km. long fragment of shelf ice 12–25 m. thick, which preserves several structural features heretofore undescribed in ice. The island is composed of an irregular central block of foliated, locally debris-rich, grey glacial ice bordered in part by extensive areas of stratified bluish sea ice. The central block contains a series of narrow, elongate, sub-parallel dike-like septa of massive fresh-water ice and a large tongue-like body of tightly folded, coarse banded ice. Both the septa and the tongue cut across the foliation and debris zones of the grey ice. The margins of the central block are penetrated by a series of elongate, crudely wedge-shaped re-entrants occupied by salients of bluish sea ice. Two broad, arch-like plunging anticlines deform the stratified sea ice along one margin of the block. The foliation and debris zones in the glacial ice are relict features inherited from the source glacier. The septa formed as crevasse and basal fracture fills. Salients represent fills formed in the irregular re-entrants along the margins of the glacial ice mass. The tongue of tightly folded, banded ice represents an earlier generation salient deformed by compressive forces as the fill built up. The broad anticlines are apparently the result of warping in response to differential ablation but the small, tight plunging folds on their noses and limbs are probably the result of compressive forces.

Synthesis of primary production in the Arctic Ocean: I. Surface waters, 1954–2007

2013 ◽  
Vol 110 ◽  
pp. 93-106 ◽  
Author(s):  
P.A. Matrai ◽  
E. Olson ◽  
S. Suttles ◽  
V. Hill ◽  
L.A. Codispoti ◽  
...  
Keyword(s):  
Primary Production ◽  
Arctic Ocean ◽  
Surface Waters ◽  
The Arctic ◽  
The Arctic Ocean

scholarly journals Impact of rapid sea-ice reduction in the Arctic Ocean on the rate of ocean acidification

2012 ◽  
Vol 9 (6) ◽  
pp. 2365-2375 ◽  
Author(s):  
A. Yamamoto ◽  
M. Kawamiya ◽  
A. Ishida ◽  
Y. Yamanaka ◽  
S. Watanabe
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Reduction Rate ◽  
Co2 Concentration ◽  
The Arctic ◽  
Saturation State ◽  
Aragonite Saturation ◽  
The Arctic Ocean ◽  
Arctic Surface ◽  
Sea Ice Reduction

Abstract. The largest pH decline and widespread undersaturation with respect to aragonite in this century due to uptake of anthropogenic carbon dioxide in the Arctic Ocean have been projected. The reductions in pH and aragonite saturation state in the Arctic Ocean have been caused by the melting of sea ice as well as by an increase in the concentration of atmospheric carbon dioxide. Therefore, future projections of pH and aragonite saturation in the Arctic Ocean will be affected by how rapidly the reduction in sea ice occurs. The observed recent Arctic sea-ice loss has been more rapid than projected by many of the climate models that contributed to the Intergovernmental Panel on Climate Change Fourth Assessment Report. In this study, the impact of sea-ice reduction rate on projected pH and aragonite saturation state in the Arctic surface waters was investigated. Reductions in pH and aragonite saturation were calculated from the outputs of two versions of an Earth system model with different sea-ice reduction rates under similar CO2 emission scenarios. The newer model version projects that Arctic summer ice-free condition will be achieved by the year 2040, and the older version predicts ice-free condition by 2090. The Arctic surface water was projected to be undersaturated with respect to aragonite in the annual mean when atmospheric CO2 concentration reaches 513 (606) ppm in year 2046 (2056) in new (old) version. At an atmospheric CO2 concentration of 520 ppm, the maximum differences in pH and aragonite saturation state between the two versions were 0.1 and 0.21 respectively. The analysis showed that the decreases in pH and aragonite saturation state due to rapid sea-ice reduction were caused by increases in both CO2 uptake and freshwater input. Thus, the reductions in pH and aragonite saturation state in the Arctic surface waters are significantly affected by the difference in future projections for sea-ice reduction rate. Our results suggest that the future reductions in pH and aragonite saturation state could be significantly faster than previously projected if the sea-ice reduction in the Arctic Ocean keeps its present pace.

scholarly journals On large-scale shifts in the Arctic Ocean and sea-ice conditions during 1979−98

2001 ◽  
Vol 33 ◽  
pp. 545-550 ◽  
Author(s):  
W. Maslowski ◽  
D. C. Marble ◽  
W. Walczowski ◽  
A. J. Semtner
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Fresh Water ◽  
Ocean Circulation ◽  
Large Scale ◽  
Atlantic Water ◽  
The Arctic ◽  
Upper Ocean ◽  
Recent Climate ◽  
The Arctic Ocean

AbstractResults from a regional model of the Arctic Ocean and sea ice forced with realistic atmospheric data are analyzed to understand recent climate variability in the region. The primary simulation uses daily-averaged 1979 atmospheric fields repeated for 20 years and then continues with interannual forcing derived from the European Centre for Medium-range Weather Forecasts for 1979−98. An eastward shift in the ice-ocean circulation, fresh-water distribution and Atlantic Water extent has been determined by comparing conditions between the early 1980s and 1990s. A new trend is modeled in the late 1990s, and has a tendency to return the large-scale sea-ice and upper ocean conditions to their state in the early 1980s. Both the sea-ice and the upper ocean circulation as well as fresh-water export from the Russian shelves and Atlantic Water recirculation within the Eurasian Basin indicate that the Arctic climate is undergoing another shift. This suggests an oscillatory behavior of the Arctic Ocean system. Interannual atmospheric variability appears to be the main and sufficient driver of simulated changes. The ice cover acts as an effective dynamic medium for vorticity transfer from the atmosphere into the ocean.

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