scholarly journals Correlated Energy Exchange in Drifting Sea Ice

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
A. Chmel ◽  
V. Smirnov
Keyword(s):  
Sea Ice ◽  
Large Scale ◽  
The Arctic ◽  
Actual State ◽  
Energy Distributions ◽  
Nonextensive Statistical Mechanics ◽  
Long Range Interactions ◽  
Measured Speed ◽  
Arctic Ice ◽  
Ice Pack

The ice floe speed variations were monitored at the research camp North Pole 35 established on the Arctic ice pack in 2008. A three-month time series of measured speed values was used for determining changes in the kinetic energy of the drifting ice floe. The constructed energy distributions were analyzed by methods of nonextensive statistical mechanics based on the Tsallis statistics for open nonequilibrium systems, such as tectonic formations and drifting sea ice. The nonextensivity means the nonadditivity of externally induced energy changes in multicomponent systems due to dynamic interrelation of components having no structural links. The Tsallis formalism gives one an opportunity to assess the correlation between ice floe motions through a specific parameter, the so-called parameter of nonextensivity. This formalistic assessment of the actual state of drifting pack allows one to forecast some important trends in sea ice behavior, because the level of correlated dynamics determines conditions for extended mechanical perturbations in ice pack. In this work, we revealed temporal fluctuations of the parameter of nonextensivity and observed its maximum value before a large-scale sea ice fragmentation (faulting) of consolidated sea ice. The correlation was not detected in fragmented sea ice where long-range interactions are weakened.

Recent behavior of the Nares Strait ice arches: anomalous collapses and enhanced export of multi-year ice from the Arctic Ocean

2020 ◽  
Author(s):  
Kent Moore ◽  
Stephen Howell ◽  
Mike Brady ◽  
Xiaoyong Xu ◽  
Kaitlin McNeil
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
The Arctic ◽  
Nares Strait ◽  
Short Period ◽  
The Arctic Ocean ◽  
Arctic Ice ◽  
Policy Communities ◽  
Ice Pack ◽  
Area And Volume

<p>The ice arches that usually develop at the northern and southern ends of Nares Strait play an important role in modulating the export of multi-year sea ice out of the Arctic Ocean.   As a result of global warming, the Arctic Ocean is evolving towards an ice pack that is younger, thinner and more mobile and the fate of its multi-year ice is becoming of increasing interest to both the scientific and policy communities.  Here, we use sea ice motion retrievals derived from Sentinel-1 imagery to report on recent behaviour of these ice arches and the associated ice flux. In addition to the previously identified early collapse of the northern ice arch in May 2017, we report that this arch failed to develop during the winters of 2018 and 2019.  In contrast, we report that the southern ice arch was only present for a short period of time during the winter of 2018.  We also show that the duration of arch formation has decreased over the past 20 years as ice in the region has thinned, while the ice area and volume fluxes have both increased.  These results suggest that a transition is underway towards a state where the formation of these arches will become atypical with a concomitant increase in the export of multi-year ice accelerating the transition towards a younger and thinner Arctic ice pack.</p>

scholarly journals Variability and changes of Arctic sea ice thickness distribution under different AO/DA states

2011 ◽  
Vol 5 (1) ◽  
pp. 131-167
Author(s):  
A. Oikkonen ◽  
J. Haapala
Keyword(s):  
Sea Ice ◽  
Seasonal Variability ◽  
Large Scale ◽  
Thickness Distribution ◽  
Beaufort Sea ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Ice Thickness ◽  
Sea Ice Thickness ◽  
Ice Pack

Abstract. Changes of the mean sea ice thickness and concentration in the Arctic are well known. However, comparable little is known about the ice thickness distribution and the composition of ice pack in quantity. In this paper we determine the ice thickness distributions, mean and modal thicknesses, and their regional and seasonal variability in the Arctic under different large scale atmospheric circulation modes. We compare characteristics of the Arctic ice pack during the periods 1975–1987 and 1988–2000, which have a different distribution in the AO/DA space. The study is based on submarine measurements of sea ice draft. The prevalent feature is that the peak of sea ice thickness distributions has generally taken a narrower form and shifted toward thinner ice. Also, both mean and modal ice thickness have generally decreased. These noticeable changes result from a loss of thick, mostly deformed, ice. In the spring the loss of the volume of ice thicker than 5 m exceeds 35% in all regions except the Nansen Basin, and the reduction is as much as over 45% at the North Pole and in the Eastern Arctic. In the autumn the volume of thick, mostly deformed ice has decreased by more than 40% in the Canada Basin only, but the reduction is more than 30% also in the Beaufort Sea and in the Chukchi Sea. In the Beaufort Sea region the decrease of the modal draft has been so strong that the peak has shifted from multiyear ice to first-year type ice. Also, the regional and seasonal variability of the sea ice thickness has decreased, since the thinning has been the most pronounced in the regions with the thickest pack ice (the Western Arctic), and during the spring (0.6–0.8 m per decade).

scholarly journals The effect of sea-ice parameterizations on the simulation of the Arctic ice pack

1997 ◽  
Vol 25 ◽  
pp. 12-16 ◽  
Author(s):  
Stephen J. Vavrus
Keyword(s):  
Heat Exchange ◽  
Sea Ice ◽  
Mixed Layer ◽  
Large Scale ◽  
Thickness Distribution ◽  
Heat Content ◽  
The Arctic ◽  
Ice Thickness ◽  
Ice Dynamics ◽  
Ice Pack

A one-dimensional (1-D), thermodynamic sea-ice model with parameterized ice dynamics is coupled to a mixed-layer ocean model and driven with prescribed atmospheric forcings for the central Arctic. The model is used to calculate the sensitivity of the ice pack to various parameterizations that have traditionally been neglected or considered only implicitly in large-scale sea-ice models. The model includes melt ponds, leads (with summertime stratification), an ice-export term, a stability-dependent air–sea heat-exchange coefficient, a prognostic ocean–ice heat exchange, a crude ice-thickness distribution, and a sophisticated albedo parameterization.The ice pack is sensitive to the partitioning of solar energy between lateral melting and mixed-layer warming, with the most realistic simulations occurring when the heat is nearly evenly divided between these two processes. Conversely, ice thickness and coverage are fairly insensitive to the amount of lateral mixing within the upper ocean, vertical mixing within leads, and to the partitioning of mixed-layer heat content between warming the water and melting the ice bottom. The ice concentration during summer is strongly dependent on the assumed ice-thickness distribution: the amount of open water during summer is less than half the size of the empirically based distribution used here, compared with one in which ice floes are distributed uniformly across a range of thicknesses.

scholarly journals Anomalous collapses of Nares Strait ice arches leads to enhanced export of Arctic sea ice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
G. W. K. Moore ◽  
S. E. L. Howell ◽  
M. Brady ◽  
X. Xu ◽  
K. McNeil
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
The Past ◽  
Nares Strait ◽  
Arctic Sea ◽  
Arctic Ice ◽  
Ice Pack ◽  
Area And Volume

AbstractThe ice arches that usually develop at the northern and southern ends of Nares Strait play an important role in modulating the export of Arctic Ocean multi-year sea ice. The Arctic Ocean is evolving towards an ice pack that is younger, thinner, and more mobile and the fate of its multi-year ice is becoming of increasing interest. Here, we use sea ice motion retrievals from Sentinel-1 imagery to report on the recent behavior of these ice arches and the associated ice fluxes. We show that the duration of arch formation has decreased over the past 20 years, while the ice area and volume fluxes along Nares Strait have both increased. These results suggest that a transition is underway towards a state where the formation of these arches will become atypical with a concomitant increase in the export of multi-year ice accelerating the transition towards a younger and thinner Arctic ice pack.

scholarly journals Satellite-derived sea ice export and its impact on Arctic ice mass balance

2018 ◽  
Vol 12 (9) ◽  
pp. 3017-3032 ◽  
Author(s):  
Robert Ricker ◽  
Fanny Girard-Ardhuin ◽  
Thomas Krumpen ◽  
Camille Lique
Keyword(s):  
Sea Ice ◽  
Mass Balance ◽  
North Atlantic ◽  
Large Scale ◽  
The Arctic ◽  
Fram Strait ◽  
Ice Volume ◽  
Ice Drift ◽  
Ice Mass Balance ◽  
Arctic Ice

Abstract. Sea ice volume export through the Fram Strait represents an important freshwater input to the North Atlantic, which could in turn modulate the intensity of the thermohaline circulation. It also contributes significantly to variations in Arctic ice mass balance. We present the first estimates of winter sea ice volume export through the Fram Strait using CryoSat-2 sea ice thickness retrievals and three different ice drift products for the years 2010 to 2017. The monthly export varies between −21 and −540 km3. We find that ice drift variability is the main driver of annual and interannual ice volume export variability and that the interannual variations in the ice drift are driven by large-scale variability in the atmospheric circulation captured by the Arctic Oscillation and North Atlantic Oscillation indices. On shorter timescale, however, the seasonal cycle is also driven by the mean thickness of exported sea ice, typically peaking in March. Considering Arctic winter multi-year ice volume changes, 54  % of their variability can be explained by the variations in ice volume export through the Fram Strait.

scholarly journals Increasing Mobility of High Arctic Sea Ice Increases Marine Hazards off the East Coast of Newfoundland

2021 ◽  
Author(s):  
David Babb ◽  
David Barber ◽  
Jens Ehn ◽  
Wayne Chan ◽  
Lisa Mathes ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Maritime Industry ◽  
Baffin Bay ◽  
Nares Strait ◽  
Fishing Vessels ◽  
Arctic Ice ◽  
Ice Pack

<p>As the Arctic ice cover has transitioned to a younger and thinner state it has become weaker and therefore increasingly mobile. One of the key indicators of this change is the increase in ice flux through Nares Strait, which connects the central Arctic to Baffin Bay and is an export pathway for some of the oldest and thickest sea ice remaining within the Arctic. Historically ice flux through the narrow Strait was seasonally limited by the formation of an ice arch, however as the ice cover has thinned the arch no longer forms every winter, and when it does form it tends to break up earlier. An increase in ice flux through Nares Strait not only affects the retention of old thick ice within the central Arctic, but also affects the icescape downstream of the Strait that extends from Baffin Bay, through the Labrador Sea and towards the southern ice edge around Newfoundland. While an ice cover does form annually around Newfoundland, it is typically a thin seasonal ice cover, which forms in January and is gone by May. However, during spring 2017 the ice conditions were considerably heavier, presenting hazardous conditions for the local maritime industry into June and requiring the Canadian Coast Guard research ice breaker Amundsen be pulled off of its scientific cruise and used to escort vessels and conduct search and rescue operations along Newfoundland’s northeast coast. The ice cover was considerably thicker and more extensive than previous years and sank two fishing vessels that became beset within the ice pack. Using a unique suite of in situ observations we confirmed that multiyear sea ice from the central Arctic was present within this anomalous ice cover. Using satellite imagery and regional ice charts we tracked the source of this multiyear ice back to Nares Strait and the central Arctic. While regional in focus, this work highlights how the decline of the Arctic ice pack has implications for downstream areas where risk may be increasing as the ice pack declines.</p>

scholarly journals Fram Strait: Possible key to saving Arctic ice

2021 ◽  
Author(s):  
Detelina Ivanova ◽  
Subarna Bhattacharyya ◽  
Leslie Field ◽  
Velimir Mlaker ◽  
Anthony Strawa ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Sea Ice ◽  
Atmospheric Dynamics ◽  
Arctic Climate ◽  
The Arctic ◽  
Fram Strait ◽  
Arctic Sea ◽  
Transpolar Drift ◽  
Arctic Ice ◽  
Ice Pack

Abstract We present a modeling study of the sensitivity of present-day Arctic climate dynamics to increases in sea ice albedo in the Fram Strait. Our analysis reveals a new mechanism whereby enhancing the albedo in the Fram Strait triggers a transition of the regional atmospheric dynamics to a negative Arctic Dipole Anomaly phase. This causes an Arctic-wide ice circulation regime, weakening Transpolar Drift and reducing Fram Strait ice export, leading to thickening of the multi-year ice pack. These findings advance our understanding of the key role that the Fram Strait plays in the Arctic climate and highlights a potential path to restoring Arctic sea ice.

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