Increasing Multiyear Sea Ice Loss in the Beaufort Sea: A New Export Pathway for the Diminishing Multiyear Ice Cover of the Arctic Ocean

2021 ◽  
Author(s):  
David Gareth Babb ◽  
Ryan J. Galley ◽  
Stephen E. L. Howell ◽  
Jack Christopher Landy ◽  
Julienne Christine Stroeve ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Beaufort Sea ◽  
Ice Cover ◽  
The Arctic ◽  
Export Pathway ◽  
The Arctic Ocean ◽  
Multiyear Ice

scholarly journals Impact of Variable Atmospheric and Oceanic Form Drag on Simulations of Arctic Sea Ice*

2014 ◽  
Vol 44 (5) ◽  
pp. 1329-1353 ◽  
Author(s):  
Michel Tsamados ◽  
Daniel L. Feltham ◽  
David Schroeder ◽  
Daniela Flocco ◽  
Sinead L. Farrell ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Form Drag ◽  
Drag Coefficients ◽  
Arctic Sea ◽  
The Arctic Ocean ◽  
Range Of Values

Abstract Over Arctic sea ice, pressure ridges and floe and melt pond edges all introduce discrete obstructions to the flow of air or water past the ice and are a source of form drag. In current climate models form drag is only accounted for by tuning the air–ice and ice–ocean drag coefficients, that is, by effectively altering the roughness length in a surface drag parameterization. The existing approach of the skin drag parameter tuning is poorly constrained by observations and fails to describe correctly the physics associated with the air–ice and ocean–ice drag. Here, the authors combine recent theoretical developments to deduce the total neutral form drag coefficients from properties of the ice cover such as ice concentration, vertical extent and area of the ridges, freeboard and floe draft, and the size of floes and melt ponds. The drag coefficients are incorporated into the Los Alamos Sea Ice Model (CICE) and show the influence of the new drag parameterization on the motion and state of the ice cover, with the most noticeable being a depletion of sea ice over the west boundary of the Arctic Ocean and over the Beaufort Sea. The new parameterization allows the drag coefficients to be coupled to the sea ice state and therefore to evolve spatially and temporally. It is found that the range of values predicted for the drag coefficients agree with the range of values measured in several regions of the Arctic. Finally, the implications of the new form drag formulation for the spinup or spindown of the Arctic Ocean are discussed.

scholarly journals Effects of Vertical Water Mass Segregation on Bacterial Community Structure in the Beaufort Sea

2019 ◽  
Vol 7 (10) ◽  
pp. 385
Author(s):  
Yunyun Fu ◽  
Richard B. Rivkin ◽  
Andrew S. Lang
Keyword(s):  
Bacterial Community ◽  
Sea Ice ◽  
Arctic Ocean ◽  
Community Composition ◽  
Bacterial Communities ◽  
Water Mass ◽  
Beaufort Sea ◽  
The Arctic ◽  
The Arctic Ocean ◽  
Mass Segregation

The Arctic Ocean is one of the least well-studied marine microbial ecosystems. Its low-temperature and low-salinity conditions are expected to result in distinct bacterial communities, in comparison to lower latitude oceans. However, this is an ocean currently in flux, with climate change exerting pronounced effects on sea-ice coverage and freshwater inputs. How such changes will affect this ecosystem are poorly constrained. In this study, we characterized the bacterial community compositions at different depths in both coastal, freshwater-influenced, and pelagic, sea-ice-covered locations in the Beaufort Sea in the western Canadian Arctic Ocean. The environmental factors controlling the bacterial community composition and diversity were investigated. Alphaproteobacteria dominated the bacterial communities in samples from all depths and stations. The Pelagibacterales and Rhodobacterales groups were the predominant taxonomic representatives within the Alphaproteobacteria. Bacterial communities in coastal and offshore samples differed significantly, and vertical water mass segregation was the controlling factor of community composition among the offshore samples, regardless of the taxonomic level considered. These data provide an important baseline view of the bacterial community in this ocean system that will be of value for future studies investigating possible changes in the Arctic Ocean in response to global change and/or anthropogenic disturbance.

scholarly journals Laboratory experiments on Internal Solitary Waves in ice covered waters 

2021 ◽  
Author(s):  
Magda Carr ◽  
Peter Sutherland ◽  
Andrea Haase ◽  
Karl-Ulrich Evers ◽  
Ilker Fer ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Solitary Waves ◽  
Ice Cover ◽  
The Arctic ◽  
Internal Solitary Waves ◽  
Small Scale ◽  
Lower Bounding ◽  
The Arctic Ocean ◽  
Wave Induced

<p>Oceanic internal waves (IWs) propagate along density interfaces and are ubiquitous in stratified water. Their properties are influenced strongly by the nature and form of the upper and lower bounding surfaces of the containing basin(s) in which they propagate.<span>  </span>As the Arctic Ocean evolves to a seasonally more ice-free state, the IW field will be affected by the change. The relationship between IW dynamics and ice is important in understanding (i) the general circulation and thermodynamics in the Arctic Ocean and (ii) local mixing processes that supply heat and nutrients from depth into upper layers, especially the photic zone. This, in turn, has important ramifications for sea ice formation processes and the state of local and regional ecosystems.<span>  </span>Despite this, the effect of diminishing sea ice cover on the IW field (and vice versa) is not well established. A better understanding of IW dynamics in the Arctic Ocean and, in particular, how the IW field is affected by changes in both ice cover and stratification, is central in understanding how the rapidly changing Arctic will adapt to climate change.</p><p> </p><p>An experimental study of internal solitary waves (ISWs) propagating in a stably stratified two-layer fluid in which the upper boundary condition changes from open water to ice are studied for grease, level, and nilas ice. The experiments show that the internal wave-induced flow at the surface is capable of transporting sea-ice in the horizontal direction. In the level ice case, the transport speed of, relatively long ice floes, nondimensionalized by the wave speed is linearly dependent on the length of the ice floe nondimensionalized by the wave length. It will also be shown that bottom roughness associated with different ice types can cause varying degrees of vorticity and small-scale turbulence in the wave-induced boundary layer beneath the ice. Measures of turbulent kinetic energy dissipation under the ice are shown to be comparable to those at the wave density interface. Moreover, in cases where the ice floe protrudes into the pycnocline, interaction with the ice edge can cause the ISW to break or even be destroyed by the process. The results suggest that interaction between ISWs and sea ice may be an important mechanism for dissipation of ISW energy in the Arctic Ocean.</p><p> </p><p><strong>Acknowledgements</strong></p><p>This work was funded through the EU Horizon 2020 Research and Innovation Programme Hydralab+.</p>

Drivers of sea ice decline in the Fram Strait and north of Svalbard 

2021 ◽  
Author(s):  
Agata Grynczel ◽  
Agnieszka Beszczynska-Moeller ◽  
Waldemar Walczowski
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Ice Cover ◽  
Atlantic Water ◽  
The Arctic ◽  
Fram Strait ◽  
Atmospheric Conditions ◽  
The North ◽  
The Arctic Ocean ◽  
Atlantic Origin

<p>The Arctic Ocean is undergoing rapid change. Satellite observations indicate significant negative Arctic sea ice extent trends in all months and substantial reduction of winter sea ice in the Atlantic sector. One of the possible reasons can be sought in the observed warming of Atlantic water, carried through Fram Strait into the Arctic Ocean. Fram Strait, as well as the region north of Svalbard, play a key role in controlling the amount of oceanic heat supplied to the Arctic Ocean and are the place of dynamic interaction between the ocean and sea ice. Shrinking sea ice cover in the southern part of Nansen Basin (north of Svalbard) and shifting the ice edge in Fram Strait are driven by the interplay between increased advection of oceanic heat in the Atlantic origin water and changes in the local atmospheric conditions.</p><p>Processes related to the loss of sea ice and the upward transport of heat from the layers of the Arctic Ocean occupied by the Atlantic water are still not fully explored, but higher than average temperature of Atlantic inflow in the Nordic Seas influence the upper ocean stratification and ice cover in the Arctic Ocean, in particular in the north of Svalbard area. The regional sea ice cover decline is statistically signifcant in all months, but the largest changes in the Nansen Basin are observed in winter season. The winter sea ice loss north of Svalbard is most pronounced above the core of the inflow warm Atlantic water. The basis for this hypothesis of the research is that continuously shrinking sea ice cover in the region north of Svalbard and withdrawal of the sea ice cover towards the northeast are driven by the interplay between increased oceanic heat in the Atlantic origin water and changes in the local atmospheric conditions, that can result in the increased ocean-air-sea ice exchange in winter seasons. In the current study we describe seasonal, interannual and decadal variability of concentration, drift, and thickness of sea ice in two regions, the north of Svalbard and central part of the Fram Strait, based on the satellite observations. To analyze the observed changes in the sea ice cover in relation to Atlantic water variability and atmospheric forcing we employ hydrographic data from the repeated CTD sections and new atmospheric reanalysis from ERA5. Atlantic water variability is described based on the set of summer synoptic sections across the Fram Strait branch of the Atlantic inflow that have been occupied annually since 1996 under the long-term observational program AREX of the Institute of Oceanology PAS. To elucidate driving mechanisms of the sea ice cover changes observed in different seasons in Fram Strait and north of Svalbard we analyze changes in the temperature, heat content and transport of the Atlantic water and describe their potential links to variable atmospheric forcing, including air temperature, air-ocean fluxes, and changes in wind pattern and wind stress.</p>

Fracture of the winter sea ice cover on the Arctic ocean

2004 ◽  
Vol 5 (7) ◽  
pp. 753-767 ◽  
Author(s):  
Erland M. Schulson ◽  
William D. Hibler
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Ice Cover ◽  
The Arctic ◽  
The Arctic Ocean

scholarly journals Arctic Research on Thin Ice: Consequences of Arctic Sea Ice Loss

Eos ◽  
2016 ◽  
Vol 97 ◽  
Author(s):  
Mats Granskog ◽  
Philipp Assmy ◽  
Sebastian Gerland ◽  
Gunnar Spreen ◽  
Harald Steen ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Arctic Sea ◽  
The Arctic Ocean ◽  
Arctic Sea Ice Loss

Scientists embarked on a 6-month expedition in the Arctic Ocean to study the thinning sea ice cover, improve our understanding of sea ice loss effects, and help predict future changes.

scholarly journals Trends in the intensity of dense water cascading from the Arctic shelves due to ice cover reduction in the Arctic seas

2021 ◽  
Vol 67 (4) ◽  
pp. 318-327
Author(s):  
F. K. Tuzov
Keyword(s):  
Arctic Ocean ◽  
Barents Sea ◽  
Beaufort Sea ◽  
Ice Cover ◽  
The Arctic ◽  
Arctic Seas ◽  
Dense Water ◽  
The Barents Sea ◽  
The Arctic Ocean ◽  
Shelf Seas

The article discusses the possible relationship between changes in the ice cover area of the shelf seas of the Arctic Ocean and the intensity of dense water cascading, based on calculation data obtained with the NEMO model for the period 1986–2010, with the findings issued at 5-day intervals and a spatial resolution of 1/10°. The cascading cases were calculated using an innovative method developed by the author. The work is based on the assumption that as the ice cover in the seas retreats, the formation of cooled dense water masses is intensified, which submerge and flow down the slope from the shelf to great depths. Thus, in the Arctic shelf seas, the mechanism of water densification due to cooling is added to the mechanism of water densification during ice formation, or, replaces it for certain regions. It was found that in the Barents Sea, the Laptev Sea and the Beaufort Sea, a decrease in the ice cover area causes an increase in the number of cases of cascading. However, in most of the Arctic seas, as the area of ice cover decreases, the number of cases of cascading also decreases. As a consequence, for the whole Arctic shelf area, the number of cases of cascading also decreases with decreasing ice cover. It is shown that in the Beaufort Sea the maximum number of cascading cases was observed in the winter period of 2007–2008, which was preceded by the summer minimum of the ice cover area in the Arctic Ocean. In the Barents Sea after 2000, a situation has been observed where the ice area has been decreasing to zero values, whereas the number of cascading cases has for some time (1 month approximately) remained close to high winter values. This possibly means that the cooling and densification of the waters in ice-free areas occurs due to thermal convection. Based on the calculation of the number of cases of cascading, it can be argued that the intensification of cascading due to a reduction in the ice cover is a feature of individual seas of the Arctic Ocean, those in which there is no excessive freshening of the upper water layer due to ice melting.

scholarly journals History of sea ice in the Arctic basin: Lessons from the past for future

2016 ◽  
Vol 56 (2) ◽  
pp. 221-234
Author(s):  
I. I. Borzenkova
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Co2 Concentration ◽  
Ice Cover ◽  
Early Pleistocene ◽  
The Arctic ◽  
Interglacial Period ◽  
The Past ◽  
The Arctic Ocean ◽  
Perennial Ice

The process of the sea ice formation in the Arctic Ocean is analyzed for the period of the last 65 million years, i.e. from the Paleocene to the present time. Appearance of sea ice in the high latitudes is demonstrated to be caused by the negative trend in global temperatures due to decreasing of the CO2 concentration in the ancient atmosphere. Formation of seasonal and perennial ice cover in the limited area near the Pole could take place during the mid-Neogene period, about 12–13 Ma ago. However, areas of the sea icing could be obviously changed for this time during periods of the climate warming and cooling. Permanent sea ice had been formed in the early Pleistocene, i.e. about 2.0–1.8 Ma ago only. Paleoclimatic reconstructions, based on the indirect data and modeling simulation for the Holocene optimum (10–6 ka ago) and for the Last Interglacial period (the isotopic substage in the marine cross-section 5e, about 125–127 ka ago) had shown that rising of global temperatures by 1.0–1.5 °C resulted in strong decreasing of the sea ice area, and the perennial ice cover became the seasonal one. Relatively small changes in the incoming solar radiation originating during the spring-summer time due to the orbital factors played the role of a trigger for onset of the melting process. Further on, the process could be enhanced owing to difference in the albedo between the ice cover and open water. Recently, the rapid shortening of the sea ice area is noted, and in some parts of the Arctic Ocean the area is twice cut down as compared with the normal. In 2015, the record low area of the winter sea ice was observed, and therewith the maximum of the ice area shifted to the earlier period (by 15 days) as compared with the period of 1981–2010. The winter fluctuations of the sea ice areas are as much important as the summer ones, since they are the best indicators of the present-day global warming. Thus, it can be supposed that some mechanism of replacing the perennial sea ice by the seasonal ones has been started up, that is the natural process of transition from seasonal ices to the next stage that is the ice-free Arctic. On the assumption that increasing of the CO2 concentration will continue despite the efforts to reduce emissions of greenhouse gases into the atmosphere, and the radiation forcing will approach to doubling of the CO2 content, one of the scenarios of the past can be realized now.

scholarly journals The Arctic sea ice cover of 2016: a year of record-low highs and higher-than-expected lows

2018 ◽  
Vol 12 (2) ◽  
pp. 433-452 ◽  
Author(s):  
Alek A. Petty ◽  
Julienne C. Stroeve ◽  
Paul R. Holland ◽  
Linette N. Boisvert ◽  
Angela C. Bliss ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
North Atlantic ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Sea Ice Extent ◽  
Atlantic Sector ◽  
Arctic Sea ◽  
The Arctic Ocean

Abstract. The Arctic sea ice cover of 2016 was highly noteworthy, as it featured record low monthly sea ice extents at the start of the year but a summer (September) extent that was higher than expected by most seasonal forecasts. Here we explore the 2016 Arctic sea ice state in terms of its monthly sea ice cover, placing this in the context of the sea ice conditions observed since 2000. We demonstrate the sensitivity of monthly Arctic sea ice extent and area estimates, in terms of their magnitude and annual rankings, to the ice concentration input data (using two widely used datasets) and to the averaging methodology used to convert concentration to extent (daily or monthly extent calculations). We use estimates of sea ice area over sea ice extent to analyse the relative “compactness” of the Arctic sea ice cover, highlighting anomalously low compactness in the summer of 2016 which contributed to the higher-than-expected September ice extent. Two cyclones that entered the Arctic Ocean during August appear to have driven this low-concentration/compactness ice cover but were not sufficient to cause more widespread melt-out and a new record-low September ice extent. We use concentration budgets to explore the regions and processes (thermodynamics/dynamics) contributing to the monthly 2016 extent/area estimates highlighting, amongst other things, rapid ice intensification across the central eastern Arctic through September. Two different products show significant early melt onset across the Arctic Ocean in 2016, including record-early melt onset in the North Atlantic sector of the Arctic. Our results also show record-late 2016 freeze-up in the central Arctic, North Atlantic and the Alaskan Arctic sector in particular, associated with strong sea surface temperature anomalies that appeared shortly after the 2016 minimum (October onwards). We explore the implications of this low summer ice compactness for seasonal forecasting, suggesting that sea ice area could be a more reliable metric to forecast in this more seasonal, “New Arctic”, sea ice regime.

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