scholarly journals Relationships between iceberg plumes and sea-ice conditions on northeast Devon Ice Cap, Nunavut, Canada

2012 ◽  
Vol 53 (60) ◽  
pp. 1-9 ◽  
Author(s):  
Emilie Herdes ◽  
Luke Copland ◽  
Brad Danielson ◽  
Martin Sharp
Keyword(s):  
Sea Ice ◽  
Strong Relationship ◽  
Time Lapse ◽  
Ice Cap ◽  
Air Temperatures ◽  
Devon Ice Cap ◽  
Ice Conditions ◽  
Landfast Sea Ice ◽  
A Minor ◽  
The Impact

AbstractThis study investigates the impact of sea-ice conditions on the production of iceberg plumes from two tidewater glaciers on Devon Ice Cap, Nunavut, Canada. These effects are quantified using a 12 year RADARSAT-1 satellite record from 1997–2008 that contains imagery from approximately every 1–2 weeks in the winter and every 1–4 days in the summer. Iceberg plumes identified in this record are verified against terrestrial time-lapse photography of Belcher Glacier from 2007–08. Results suggest a strong relationship between iceberg plumes and the retreat of sea ice from the glacier termini, with the plumes caused by both the release of previously calved icebergs (ice melange) and new glacier calving. Iceberg plumes are also sometimes observed at other times in the summer and in midwinter (occasionally on both glaciers simultaneously), with these events likely due to new glacier calving alone. Analysis of tides and air temperatures suggests that they provide a minor influence on the timing of iceberg plumes. Instead, it appears that changes in the presence of sea ice are dominant on seasonal timescales, although internal glacier dynamics likely play a significant role for winter plume events that occur when substantial thicknesses of landfast sea ice are present.

scholarly journals Exceptional retreat of Novaya Zemlya's marine-terminating outlet glaciers between 2000 and 2013

2017 ◽  
Author(s):  
J. Rachel Carr ◽  
Heather Bell ◽  
Rebecca Killick ◽  
Tom Holt
Keyword(s):  
Sea Ice ◽  
Sea Level Rise ◽  
Sea Level ◽  
Remotely Sensed ◽  
Glacier Retreat ◽  
Remotely Sensed Data ◽  
Novaya Zemlya ◽  
The Past ◽  
Air Temperatures ◽  
The Impact

Abstract. Novaya Zemlya (NVZ) has experienced rapid ice loss and accelerated marine-terminating glacier retreat during the past two decades. However, it is unknown whether this retreat is exceptional longer-term and/or whether it has persisted since 2010. Investigating this is vital, as dynamic thinning may contribute substantially to ice loss from NVZ, but is not currently included in sea level rise predictions. Here, we use remotely sensed data to assess controls on NVZ glacier retreat between the 1973/6 and 2015. Glaciers that terminate into lakes or the ocean receded 3.5 times faster than those that terminate on land. Between 2000 and 2013, retreat rates were significantly higher on marine-terminating outlet glaciers than during the previous 27 years, and we observe widespread slow-down in retreat, and even advance, between 2013 and 2015. There were some common patterns in the timing of glacier retreat, but the magnitude varied between individual glaciers. Rapid retreat between 2000–2013 corresponds to a period of significantly warmer air temperatures and reduced sea ice concentrations, and to changes in the NAO and AMO. We need to assess the impact of this accelerated retreat on dynamic ice losses from NVZ, to accurately quantify its future sea level rise contribution.

scholarly journals Modelling landfast sea ice and its influence on ocean-ice interactions in the area of the Totten Glacier, East Antarctica

2021 ◽  
Author(s):  
Guillian Van Achter ◽  
Thierry Fichefet ◽  
Hugues Goosse ◽  
Charles Pelletier ◽  
Jean Sterlin ◽  
...  
Keyword(s):  
Sea Ice ◽  
Climate Models ◽  
Mixed Layer Depth ◽  
Global Climate Models ◽  
East Antarctica ◽  
Ice Shelf ◽  
Sea Ice Extent ◽  
Coastal Polynya ◽  
Landfast Sea Ice ◽  
The Impact

<p>The Totten Glacier in East Antarctica is of major climate interest because of the large fluctuation of its grounding line and of its potential vulnerability to climate change. The ocean above the continental shelf in front of the Totten ice shelf exhibits large extents of landfast sea ice with low interannual variability. Landfast sea ice is mostly not or sole crudely represented in current climate models. These models are potentially omitting or misrepresenting important effects related to this type of sea ice, such as its influence on coastal polynya locations. Yet, the impact of the landfast sea<br>ice on the ocean – ice shelf interactions is poorly understood. Using a series of high-resolution, regional NEMO-LIM-based experiments including an<br>explicit treatment of ocean – ice shelf interactions over the years 2001-2010, we simulate a realistic landfast sea ice extent in the area of Totten Glacier<br>through a combination of a sea ice tensile strength parameterisation and a grounded iceberg representation. We show that the presence of landfast sea<br>ice impacts seriously both the location of coastal polynyas and the ocean mixed layer depth along the coast, in addition to favouring the intrusion of<br>mixed Circumpolar Deep Water into the ice shelf cavities. Depending on the local bathymetry and the landfast sea ice distribution, landfast sea ice affects ice shelf cavities in different ways, either by increasing the ice melt (+28% for the Moscow University ice shelf) or by reducing its seasonal cycle<br>(+10% in March-May for the Totten ice shelf). This highlights the importance of including an accurate landfast sea ice representation in regional and<br>eventually global climate models</p>

scholarly journals Evidence for an increasing role of ocean heat in Arctic winter sea ice growth

2021 ◽  
pp. 1-42
Author(s):  
Robert Ricker ◽  
Frank Kauker ◽  
Axel Schweiger ◽  
Stefan Hendricks ◽  
Jinlun Zhang ◽  
...  
Keyword(s):  
Sea Ice ◽  
Reanalysis Data ◽  
Arctic Sea Ice ◽  
Satellite Observations ◽  
The Arctic ◽  
Ice Growth ◽  
Marginal Seas ◽  
Air Temperatures ◽  
Barents And Kara Seas ◽  
The Impact

AbstractWe investigate how sea ice decline in summer and warmer ocean and surface temperatures in winter affect sea ice growth in the Arctic. Sea ice volume changes are estimated from satellite observations during winter from 2002 to 2019 and partitioned into thermodynamic growth and dynamic volume change. Both components are compared to validated sea ice-ocean models forced by reanalysis data to extend observations back to 1980 and to understand the mechanisms that cause the observed trends and variability. We find that a negative feedback driven by the increasing sea ice retreat in summer yields increasing thermodynamic ice growth during winter in the Arctic marginal seas eastward from the Laptev Sea to the Beaufort Sea. However, in the Barents and Kara Seas, this feedback seems to be overpowered by the impact of increasing oceanic heat flux and air temperatures, resulting in negative trends in thermodynamic ice growth of -2 km3month-1yr-1 on average over 2002-2019 derived from satellite observations.

Landfast Sea Ice Conditions in the Canadian Arctic: 1983 – 2009

ARCTIC ◽  
2012 ◽  
Vol 65 (2) ◽  
Author(s):  
Ryan J. Galley ◽  
Brent G.T. Else ◽  
Stephen E.L. Howell ◽  
Jennifer V. Lukovich ◽  
David G. Barber
Keyword(s):  
Sea Ice ◽  
Canadian Arctic ◽  
Ice Conditions ◽  
Landfast Sea Ice

The impact of denying sea ice information on the predictability of atmospheric processes over the Arctic and at mid-latitude regions

2020 ◽  
Author(s):  
Leandro Ponsoni ◽  
Daniela Flocco ◽  
François Massonnet ◽  
Steve Delhaye ◽  
Ed Hawkins ◽  
...  
Keyword(s):  
Sea Ice ◽  
General Circulation ◽  
Model Comparison ◽  
General Circulation Models ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Atmospheric Processes ◽  
Ice Conditions ◽  
The Impact

<p>In this work, we make use of an inter-model comparison and of a perfect model approach, in which model outputs are used as true reference states, to assess the impact that denying sea ice information has on the prediction of atmospheric processes, both over the Arctic and at mid-latitude regions. To do so, two long-term control runs (longer than 250 years) were generated with two state-of-the-art General Circulation Models (GCM), namely EC-Earth and HadGEM. From these two reference states, we have identified three different years in which the Arctic sea ice volume (SIV) was (i) maximum, (ii) minimum and (iii) a representative case for the mean state. By departing from each of these three dates (not necessarily the same for the two models), we generated a set of experiments in which the control runs are restarted both from original and climatological sea ice conditions. Here, climatological sea ice conditions are estimated as the time-average of sea ice parameters from the respective long-term control runs. The experiments are 1-year long and all of them start in January when ice is still thin, snow depth is small, air-ocean temperatures contrast the most and, therefore, the heat conductive flux in sea ice (at the surface) is nearly maximum. To robustly separate the response to degrading the initial sea ice state from background internal variability, each of the two counterfactual experiments (reference and climatological) consists of 50 ensembles members. Threstatedese ensembles are generated by adding small random perturbations to the sea surface temperature (EC-Earth) or to the air temperature (HadGEM) fields. Preliminary results reinforce the importance of having the right sea ice state for improving the (sub-)seasonal prediction of atmospheric parameters (e.g., 2m-temperature and geopotential) and circulation (e.g., Westerlies and Jet Stream) not only over the Arctic, but also at mid-latitude regions.</p>

The impact of sea ice conditions on breeding decisions is modulated by body condition in an arctic partial capital breeder

Oecologia ◽  
2017 ◽  
Vol 186 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Frankie Jean-Gagnon ◽  
P. Legagneux ◽  
G. Gilchrist ◽  
S. Bélanger ◽  
O. P. Love ◽  
...  
Keyword(s):  
Sea Ice ◽  
Body Condition ◽  
Capital Breeder ◽  
Ice Conditions ◽  
The Impact

scholarly journals InSAR monitoring of Arctic land fast sea ice deformation using L-band ALOS-2, C-band Radarsat-2 and Sentinel-1

2021 ◽  
Author(s):  
Zhaohua Chen ◽  
Benoit Montpetit ◽  
Sarah Banks ◽  
Lori White ◽  
Amir Behnamian ◽  
...  
Keyword(s):  
Sea Ice ◽  
Process Time ◽  
Polar Climate ◽  
Ice Surface ◽  
Ice Conditions ◽  
Small Baseline Subset ◽  
L Band ◽  
Landfast Sea Ice ◽  
Small Baseline ◽  
The Stability

Abstract. Arctic amplification is accelerating changes in sea ice regimes in the Canadian Arctic with later freeze-up and earlier melt events, adversely affecting Arctic wildlife and communities that depend on the stability of the sea ice conditions. To monitor both the rate and impact of such change, there is a need to accurately measure sea ice deformation, an important component for understanding ice motion and polar climate. This paper presents Interferometric Synthetic Aperture Radar (InSAR) monitoring of Arctic landfast sea ice deformation as a result of thickness changes measured from ice draft and surface height using C-band Radarsat-2, Sentinel-1 and L-band ALOS-2. The small baseline subset (SBAS) approach was explored to process time series observations for retrieval of temporal deformation changes over the winter. Sea ice deformation (subsidence and uplift in the range of −32–57 cm) detected from satellite SAR data in Cambridge Bay, Nunavut, Canada during the winter of 2018–2019 was found to be in a range of values corresponding to the ice draft growth (30–62 cm) measured from an in-situ ice profiler. The trends of InSAR observations from Sentinel-1 were also consistent with ice surface height changes along two ground tracks detected from ICESat-2. SAR backscatter from Sentinel-1 also corresponded to the surface height with strong correlation coefficient (0.49–0.83). High coherence over ice from C-band was maintained over a shorter acquisition interval than L-band due to temporal decorrelation.

scholarly journals Combining TerraSAR-X and time-lapse photography for seasonal sea ice monitoring: the case of Deception Bay, Nunavik

2020 ◽  
Vol 14 (5) ◽  
pp. 1595-1609 ◽  
Author(s):  
Sophie Dufour-Beauséjour ◽  
Anna Wendleder ◽  
Yves Gauthier ◽  
Monique Bernier ◽  
Jimmy Poulin ◽  
...  
Keyword(s):  
Time Series ◽  
Sea Ice ◽  
Mining Industry ◽  
Time Lapse ◽  
Combined Use ◽  
X Band ◽  
Ice Conditions ◽  
Data Source ◽  
Breakup Time ◽  
Time Lapse Photography

Abstract. This article presents a case study for the combined use of TerraSAR-X and time-lapse photography time series in order to monitor seasonal sea ice processes in Nunavik's Deception Bay. This area is at the confluence of land use by local Inuit, ice-breaking transport by the mining industry, and climate change. Indeed, Inuit have reported greater interannual variability in seasonal sea ice conditions, including later freeze-up and earlier breakup. Time series covering 2015 to 2018 were acquired for each data source: TerraSAR-X images were acquired every 11 d, and photographs were acquired hourly during the day. We used the combination of the two time series to document spatiotemporal aspects of freeze-up and breakup processes. We also report new X-band backscattering values over newly formed sea ice types. The TerraSAR-X time series further show potential for melt and pond onset.

scholarly journals Summer Sea Ice Albedo in the Arctic in CMIP5 models

2013 ◽  
Vol 13 (9) ◽  
pp. 25219-25251 ◽  
Author(s):  
T. Koenigk ◽  
A. Devasthale ◽  
K.-G. Karlsson
Keyword(s):  
Sea Ice ◽  
Large Scale ◽  
High Surface ◽  
Temporal Variations ◽  
Satellite Observations ◽  
The Arctic ◽  
Cmip5 Models ◽  
Cold Temperatures ◽  
Ice Conditions ◽  
The Impact

Abstract. Spatial and temporal variations of summer sea ice albedo over the Arctic are analyzed using an ensemble of historical CMIP5 model simulations. The results are compared to the CLARA-SAL product that is based on long-term satellite observations. The summer sea ice albedo varies substantially among CMIP5 models and many models show large biases compared to the CLARA-SAL product. Single summer months show an extreme spread of ice albedo among models; July-values vary between 0.3 and 0.7 for individual models. The CMIP5 ensemble mean, however, agrees relatively well in the Central Arctic but shows too high ice albedo near the ice edges and coasts. In most models, the ice albedo is spatially too uniformly distributed. The summer to summer variations seem to be underestimated in many global models and almost no model is able to fully reproduce the temporal evolution of ice albedo throughout the summer. While the satellite observations indicate the lowest ice albedos during August, the models show minimum values in July and substantially higher values in August. Instead, the June values are often lower in the models than in the satellite observations. This is probably due to too high surface temperatures in June, leading to an early start of the melt season and too cold temperatures in August causing an earlier refreezing in the models. The summer sea ice albedo in the CMIP5 models is strongly governed by surface temperature and snow conditions, particularly during the period of melt onset in early summer and refreezing in late summer. The summer surface net solar radiation of the ice covered Arctic areas is highly related to the ice albedo in the CMIP5 models. However, the impact of the ice albedo on the sea ice conditions in the CMIP5 models is not clearly visible. This indicates the importance of other Arctic and large scale processes for the sea ice conditions.

scholarly journals Summer Arctic sea ice albedo in CMIP5 models

2014 ◽  
Vol 14 (4) ◽  
pp. 1987-1998 ◽  
Author(s):  
T. Koenigk ◽  
A. Devasthale ◽  
K.-G. Karlsson
Keyword(s):  
Sea Ice ◽  
Large Scale ◽  
High Surface ◽  
Arctic Sea Ice ◽  
Satellite Observations ◽  
The Arctic ◽  
Cmip5 Models ◽  
Cold Temperatures ◽  
Ice Conditions ◽  
The Impact

Abstract. Spatial and temporal variations of summer sea ice albedo over the Arctic are analyzed using an ensemble of historical CMIP5 model simulations. The results are compared to the CLARA-SAL product that is based on long-term satellite observations. The summer sea ice albedo varies substantially among CMIP5 models, and many models show large biases compared to the CLARA-SAL product. Single summer months show an extreme spread of ice albedo among models; July values vary between 0.3 and 0.7 for individual models. The CMIP5 ensemble mean, however, agrees relatively well in the central Arctic but shows too high ice albedo near the ice edges and coasts. In most models, the ice albedo is spatially too uniformly distributed. The summer-to-summer variations seem to be underestimated in many global models, and almost no model is able to reproduce the temporal evolution of ice albedo throughout the summer fully. While the satellite observations indicate the lowest ice albedos during August, the models show minimum values in July and substantially higher values in August. Instead, the June values are often lower in the models than in the satellite observations. This is probably due to too high surface temperatures in June, leading to an early start of the melt season and too cold temperatures in August causing an earlier refreezing in the models. The summer sea ice albedo in the CMIP5 models is strongly governed by surface temperature and snow conditions, particularly during the period of melt onset in early summer and refreezing in late summer. The summer surface net solar radiation of the ice-covered Arctic areas is highly related to the ice albedo in the CMIP5 models. However, the impact of the ice albedo on the sea ice conditions in the CMIP5 models is not clearly visible. This indicates the importance of other Arctic and large-scale processes for the sea ice conditions.

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