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Corrigendum: Recent increases in Arctic freshwater flux affects Labrador Sea convection and Atlantic overturning circulation.

https://arctichealth.org/en/permalink/ahliterature277771
Source
Nat Commun. 2016 Nov 17;7:13545
Publication Type
Article
Date
Nov-17-2016

Land Ice Freshwater Budget of the Arctic and North Atlantic Oceans: 1. Data, Methods, and Results.

https://arctichealth.org/en/permalink/ahliterature292558
Source
J Geophys Res Oceans. 2018 Mar; 123(3):1827-1837
Publication Type
Journal Article
Date
Mar-2018
Author
J L Bamber
A J Tedstone
M D King
I M Howat
E M Enderlin
M R van den Broeke
B Noel
Author Affiliation
School of Geographical Sciences University of Bristol Bristol UK.
Source
J Geophys Res Oceans. 2018 Mar; 123(3):1827-1837
Date
Mar-2018
Language
English
Publication Type
Journal Article
Abstract
The freshwater budget of the Arctic and sub-polar North Atlantic Oceans has been changing due, primarily, to increased river runoff, declining sea ice and enhanced melting of Arctic land ice. Since the mid-1990s this latter component has experienced a pronounced increase. We use a combination of satellite observations of glacier flow speed and regional climate modeling to reconstruct the land ice freshwater flux from the Greenland ice sheet and Arctic glaciers and ice caps for the period 1958-2016. The cumulative freshwater flux anomaly exceeded 6,300?±?316 km3 by 2016. This is roughly twice the estimate of a previous analysis that did not include glaciers and ice caps outside of Greenland and which extended only to 2010. From 2010 onward, the total freshwater flux is about 1,300 km3/yr, equivalent to 0.04 Sv, which is roughly 40% of the estimated total runoff to the Arctic for the same time period. Not all of this flux will reach areas of deep convection or Arctic and Sub-Arctic seas. We note, however, that the largest freshwater flux anomalies, grouped by ocean basin, are located in Baffin Bay and Davis Strait. The land ice freshwater flux displays a strong seasonal cycle with summer time values typically around five times larger than the annual mean. This will be important for understanding the impact of these fluxes on fjord circulation, stratification, and the biogeochemistry of, and nutrient delivery to, coastal waters.
Notes
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PubMed ID
29938150 View in PubMed
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Low elevation of Svalbard glaciers drives high mass loss variability.

https://arctichealth.org/en/permalink/ahliterature304747
Source
Nat Commun. 2020 09 14; 11(1):4597
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Date
09-14-2020
Author
Brice Noël
C L Jakobs
W J J van Pelt
S Lhermitte
B Wouters
J Kohler
J O Hagen
B Luks
C H Reijmer
W J van de Berg
M R van den Broeke
Author Affiliation
Institute for Marine and Atmospheric research Utrecht, Utrecht University, 3584 CC, Utrecht, Netherlands. b.p.y.noel@uu.nl.
Source
Nat Commun. 2020 09 14; 11(1):4597
Date
09-14-2020
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Abstract
Compared to other Arctic ice masses, Svalbard glaciers are low-elevated with flat interior accumulation areas, resulting in a marked peak in their current hypsometry (area-elevation distribution) at  ~450?m above sea level. Since summer melt consistently exceeds winter snowfall, these low-lying glaciers can only survive by refreezing a considerable fraction of surface melt and rain in the porous firn layer covering their accumulation zones. We use a high-resolution climate model to show that modest atmospheric warming in the mid-1980s forced the firn zone to retreat upward by  ~100 m to coincide with the hypsometry peak. This led to a rapid areal reduction of firn cover available for refreezing, and strongly increased runoff from dark, bare ice areas, amplifying mass loss from all elevations. As the firn line fluctuates around the hypsometry peak in the current climate, Svalbard glaciers will continue to lose mass and show high sensitivity to temperature perturbations.
PubMed ID
32929066 View in PubMed
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Rapid expansion of Greenland's low-permeability ice slabs.

https://arctichealth.org/en/permalink/ahliterature308952
Source
Nature. 2019 09; 573(7774):403-407
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Date
09-2019
Author
M MacFerrin
H Machguth
D van As
C Charalampidis
C M Stevens
A Heilig
B Vandecrux
P L Langen
R Mottram
X Fettweis
M R van den Broeke
W T Pfeffer
M S Moussavi
W Abdalati
Author Affiliation
Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA. michael.macferrin@colorado.edu.
Source
Nature. 2019 09; 573(7774):403-407
Date
09-2019
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Keywords
Freezing
Global warming
Greenland
Ice Cover
Models, Theoretical
Abstract
In recent decades, meltwater runoff has accelerated to become the dominant mechanism for mass loss in the Greenland ice sheet1-3. In Greenland's high-elevation interior, porous snow and firn accumulate; these can absorb surface meltwater and inhibit runoff4, but this buffering effect is limited if enough water refreezes near the surface to restrict percolation5,6. However, the influence of refreezing on runoff from Greenland remains largely unquantified. Here we use firn cores, radar observations and regional climate models to show that recent increases in meltwater have resulted in the formation of metres-thick, low-permeability 'ice slabs' that have expanded the Greenland ice sheet's total runoff area by 26 ± 3 per cent since 2001. Although runoff from the top of ice slabs has added less than one millimetre to global sea-level rise so far, this contribution will grow substantially as ice slabs expand inland in a warming climate. Runoff over ice slabs is set to contribute 7 to 33 millimetres and 17 to 74 millimetres to global sea-level rise by 2100 under moderate- and high-emissions scenarios, respectively-approximately double the estimated runoff from Greenland's high-elevation interior, as predicted by surface mass balance models without ice slabs. Ice slabs will have an important role in enhancing surface meltwater feedback processes, fundamentally altering the ice sheet's present and future hydrology.
PubMed ID
31534244 View in PubMed
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Recent increases in Arctic freshwater flux affects Labrador Sea convection and Atlantic overturning circulation.

https://arctichealth.org/en/permalink/ahliterature269512
Source
Nat Commun. 2016;7:10525
Publication Type
Article
Date
2016
Author
Qian Yang
Timothy H Dixon
Paul G Myers
Jennifer Bonin
Don Chambers
M R van den Broeke
Source
Nat Commun. 2016;7:10525
Date
2016
Language
English
Publication Type
Article
Abstract
The Atlantic Meridional Overturning Circulation (AMOC) is an important component of ocean thermohaline circulation. Melting of Greenland's ice sheet is freshening the North Atlantic; however, whether the augmented freshwater flux is disrupting the AMOC is unclear. Dense Labrador Sea Water (LSW), formed by winter cooling of saline North Atlantic water and subsequent convection, is a key component of the deep southward return flow of the AMOC. Although LSW formation recently decreased, it also reached historically high values in the mid-1990s, making the connection to the freshwater flux unclear. Here we derive a new estimate of the recent freshwater flux from Greenland using updated GRACE satellite data, present new flux estimates for heat and salt from the North Atlantic into the Labrador Sea and explain recent variations in LSW formation. We suggest that changes in LSW can be directly linked to recent freshening, and suggest a possible link to AMOC weakening.
PubMed ID
26796579 View in PubMed
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