A new coupled model to shed light on sea-ice--ocean interactions

Sea ice is a key component of the earth&#8217;s climate system as it modulates air-sea interactions in polar regions. These interactions strongly depend on openings in the sea ice cover, which are associated with fine-scale sea ice deformations. Visco-plastic sea ice rheologies used in most numerical models struggle at representing these fine-scale sea ice dynamics without going to very costly horizontal resolutions (~1km). A solution is to use damage propagation sea ice models, which were shown to reproduce well sea ice deformations with little dependency on the mesh resolution.&#160;Here we present results from the first ocean--sea-ice coupled model using a rheology with damage propagation. The ocean component is the NEMO-OPA model. The sea ice component is neXtSIM, introducing the newly developed Brittle Bingham-Maxwell rheology. Results show that sea ice dynamics are very well represented from large scales (sea ice drift) to small-scales (sea ice deformation). Sea ice properties relevant for climate, i.e volume and area, also show a remarkable match with satellite observations. This coupled framework opens new opportunities to quantify the impact of small-scale sea ice dynamics on ice-ocean interactions.

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Sea-ice dynamics in the Weddell Sea in winter

Annals of Glaciology ◽

10.3189/1991aog15-1-9-16 ◽

1991 ◽

Vol 15 ◽

pp. 9-16 ◽

Cited By ~ 1

Author(s):

Heinrich Hoeber

Keyword(s):

Sea Ice ◽

Bulk Viscosity ◽

Current Data ◽

Weddell Sea ◽

Small Scale ◽

Ice Dynamics ◽

Sea Ice Dynamics ◽

Momentum Budget ◽

Ice Drift

Observations of ice drift received from an array of ARGOS buoys drifting in the Weddell Sea in winter 1986 are described. Wind and current data are also available, permitting derivation of the complete momentum budget including the internal ice stress computed as residuum. It is shown that the variability of forcing both of the atmosphere and of the ocean is large, and that internal ice stress is not negligible; monthly vector averages amount to about half of the wind and water stresses. Coefficients of shear and bulk viscosity are derived according to Hibler's model of ice rheology; they turn out to be negative occasionally, in particular when small-scale forcing of the atmosphere is large.

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Brief communication: lack of agreement in remote sensing detection of cyclonic drift caused by Atlantic weather in Antarctic sea ice

10.5194/tc-2021-144 ◽

2021 ◽

Author(s):

Wayne de Jager ◽

Marcello Vichi

Keyword(s):

Remote Sensing ◽

Sea Ice ◽

Alternative Methods ◽

Polar Regions ◽

Sea Ice Concentration ◽

Sea Ice Extent ◽

Ice Dynamics ◽

Antarctic Sea Ice ◽

Ice Drift ◽

The Impact

Abstract. Sea-ice extent variability, a measure based on satellite-derived sea ice concentration measurements, has traditionally been used as an essential climate variable to evaluate the impact of climate change on polar regions. However, concentration- based measurements of ice variability do not allow to discriminate the relative contributions made by thermodynamic and dynamic processes, prompting the need to use sea-ice drift products and develop alternative methods to quantify changes in sea ice dynamics that would indicate trends in Antarctic ice characteristics. Here, we present a new method to automate the detection of rotational drift features in Antarctic sea ice at daily timescales using currently available remote sensing ice motion products from EUMETSAT OSI SAF. Results show that there is a large discrepancy in the detection of cyclonic drift features between products, both in terms of intensity and year-to-year distributions, thus diminishing the confidence at which ice drift variability can be further analysed. Product comparisons showed that there was good agreement in detecting anticyclonic drift, and cyclonic drift features were measured to be 1.5–2.2 times more intense than anticyclonic features. The most intense features were detected by the merged product, suggesting that the processing chain used for this product could be injecting additional rotational momentum into the resultant drift vectors. We conclude that it is therefore necessary to better understand why the products lack agreement before further trend analysis of these drift features and their climatic significance can be assessed.

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The impact of sea-ice dynamics on the Arctic climate system

Climate Dynamics ◽

10.1007/s00382-003-0309-5 ◽

2003 ◽

Vol 20 (7-8) ◽

pp. 741-757 ◽

Cited By ~ 38

Author(s):

S. Vavrus ◽

S. P. Harrison

Keyword(s):

Sea Ice ◽

Climate System ◽

Arctic Climate ◽

The Arctic ◽

Ice Dynamics ◽

Sea Ice Dynamics ◽

The Impact

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Investigating the dynamics of an Antarctic coastal polynya using a regional climate model

10.5194/egusphere-egu2020-19677 ◽

2020 ◽

Author(s):

Pierre-Vincent Huot ◽

Thierry Fichefet ◽

Christoph Kittel ◽

Nicolas Jourdain ◽

Xavier Fettweis

Keyword(s):

Sea Ice ◽

Climate Model ◽

Regional Climate ◽

Coupled Model ◽

Polar Regions ◽

Coupled Models ◽

Polar Climate ◽

Coastal Polynya ◽

The Impact ◽

Regional Coupled Model

Coastal polynyas of the Southern Ocean, such as the Mertz Glacier Polynya, are paramount features of the polar climate. They allow for exchanges of heat, momentum and moisture between the atmosphere and ocean where sea ice usually prevents such interactions. Polynyas are believed to have a profound impact on polar and global climate, thanks to their sustained sea ice production and the associated formation of Dense Shelf Waters. Less is known, however, about the impact of polynyas on the atmosphere. Changes in air properties and winds induced by heat and moisture flux could for instance affect precipitation regime over the ice sheet or sea ice. As the formation and evolution of coastal polynyas are tied to the state of the atmosphere, such changes can also induce important feedbacks to polynyas dynamics. Such processes have almost never been studied, whether on the field or with the help of coupled models. Here, we propose to describe the behavior of a coastal polynya and its relationship with the ocean and atmosphere. To do so, we developed a regional coupled model of the ocean, sea ice and atmosphere (including interactive basal melt of ice shelves) and applied it to the Ad&#233;lie Land area, in East Antarctica. The dynamics of the Mertz Glacier Polynya is described, together with its impact on the atmosphere, sea ice growth, dense water production and ice shelf melt. To assess the importance of potential feedbacks, we compare the dynamics of the polynya from the coupled model to a forced ocean-sea ice model. We then use the regional coupled model to investigate the implications of the Mertz ice tongue calving in early 2010 which led to a drastic decrease of the Mertz Glacier Polynya extent. This experiment aims at investigating the sensitivity of the atmosphere to the activity of the polynya and to evaluate the impact of the calving on regional climate. This work improves the understanding of the Mertz Glacier Polynya dynamics, and of the impact of coastal polynyas on polar climate. It also constitutes an additional step in the modelling of the polar regions in Earth System Models.

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Impact of wave-induced sea ice fragmentation on sea ice dynamics in the MIZ

10.5194/egusphere-egu2020-8657 ◽

2020 ◽

Author(s):

Guillaume Boutin ◽

Timothy Williams ◽

Pierre Rampal ◽

Einar Olason ◽

Camille Lique

Keyword(s):

Sea Ice ◽

Barents Sea ◽

Ice Cover ◽

Arctic Sea Ice ◽

The Arctic ◽

Sea Ice Extent ◽

Ice Dynamics ◽

Sea Ice Dynamics ◽

Wave Induced ◽

The Impact

The decrease in Arctic sea ice extent is associated with an increase of the area where sea ice and open ocean interact, commonly referred to as the Marginal Ice Zone (MIZ). In this area, sea ice is particularly exposed to waves that can penetrate over tens to hundreds of kilometres into the ice cover. Waves are known to play a major role in the fragmentation of sea ice in the MIZ, and the interactions between wave-induced sea ice fragmentation and lateral melting have received particular attention in recent years. The impact of this fragmentation on sea ice dynamics, however, remains mostly unknown, although it is thought that fragmented sea ice experiences less resistance to deformation than pack ice. In this presentation, we will introduce a new coupled framework involving the spectral wave model WAVEWATCH III and the sea ice model neXtSIM, which includes a Maxwell-Elasto Brittle rheology. We use this coupled modelling system to investigate the potential impact of wave-induced sea ice fragmentation on sea ice dynamics. Focusing on the Barents Sea, we find that the decrease of the internal stress of sea ice resulting from its fragmentation by waves results in a more dynamical MIZ, in particular in areas where sea ice is compact. Sea ice drift is enhanced for both on-ice and off-ice wind conditions. Our results stress the importance of considering wave&#8211;sea-ice interactions for forecast applications. They also suggest that waves likely modulate the area of sea ice that is advected away from the pack by ocean (sub-)mesoscale eddies near the ice edge, potentially contributing to the observed past, current and future sea ice cover decline in the Arctic.&#160;

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Wave–sea-ice interactions in a brittle rheological framework

10.5194/tc-2020-19 ◽

2020 ◽

Author(s):

Guillaume Boutin ◽

Timothy Williams ◽

Pierre Rampal ◽

Einar Olason ◽

Camille Lique

Keyword(s):

Sea Ice ◽

Barents Sea ◽

Ice Cover ◽

Arctic Sea Ice ◽

The Arctic ◽

Sea Ice Extent ◽

Ice Dynamics ◽

Sea Ice Dynamics ◽

Wave Induced ◽

The Impact

Abstract. The decrease in Arctic sea ice extent is associated with an increase of the area where sea ice and open ocean interact, commonly referred to as the Marginal Ice Zone (MIZ). In this area, sea ice is particularly exposed to waves that can penetrate over tens to hundreds of kilometres into the ice cover. Waves are known to play a major role in the fragmentation of sea ice in the MIZ, and the interactions between wave-induced sea ice fragmentation and lateral melting have received particular attention in recent years. The impact of this fragmentation on sea ice dynamics, however, remains mostly unknown, although it is thought that fragmented sea ice experiences less resistance to deformation than pack ice. Here, we introduce a new coupled framework involving the spectral wave model WAVEWATCH III and the sea ice model neXtSIM, which includes a Maxwell-Elasto Brittle rheology. We use this coupled modelling system to investigate the potential impact of wave-induced sea ice fragmentation on sea ice dynamics. Focusing on the Barents Sea, we find that the decrease of the internal stress of sea ice resulting from its fragmentation by waves results in a more dynamical MIZ, in particular in areas where sea ice is compact. Sea ice drift is enhanced for both on-ice and off-ice wind conditions. Our results stress the importance of considering wave–sea-ice interactions for forecast applications. They also suggest that waves likely modulate the area of sea ice that is advected away from the pack by ocean (sub-)mesoscale eddies near the ice edge, potentially contributing to the observed past, current and future sea ice cover decline in the Arctic.

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Temperature, carbon dioxide and methane

10.21203/rs.3.rs-558940/v2 ◽

2022 ◽

Author(s):

Clive Hambler ◽

Peter A. Henderson

Keyword(s):

Carbon Dioxide ◽

Sea Ice ◽

Polar Regions ◽

Time Lags ◽

Strongly Correlated ◽

Sea Ice Extent ◽

Ice Dynamics ◽

Mauna Loa ◽

Rates Of Change ◽

Sea Ice Dynamics

Abstract 1) Globally-representative monthly rates of change of atmospheric carbon dioxide and methane are compared with global rates of change of sea ice and with Arctic and Antarctic air temperatures. 2) Carbon dioxide is very strongly correlated with sea ice dynamics, with the carbon dioxide rate at Mauna Loa lagging sea ice extent rate by 7 months. 3) Methane is very strongly correlated with sea ice dynamics, with the global (and Mauna Loa) methane rate lagging sea ice extent rate by 5 months. 4) Sea ice melt rate peaks in very tight synchrony with temperature in each Hemisphere. 5) The very high synchrony of the two gases is most parsimoniously explained by a common causality acting in both Hemispheres. 6) Time lags between variables indicate primary drivers of the gas dynamics are due to solar action on the polar regions, not mid-latitudes as is conventionally believed. 7) Results are consistent with a proposed role of a high-latitude temperature-dependent abiotic variable such as sea ice in the annual cycles of carbon dioxide and methane. 8) If sea ice does not drive the net flux of these gases, it is a highly precise proxy for whatever does. 9) Potential mechanisms should be investigated urgently.

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IcePAC – a Probabilistic Tool to Study Sea Ice Spatiotemporal Dynamic: Application to the Hudson Bay area, Northeastern Canada

10.5194/tc-2018-178 ◽

2018 ◽

Author(s):

Charles Gignac ◽

Monique Bernier ◽

Karem Chokmani

Keyword(s):

Sea Ice ◽

Numerical Models ◽

Hudson Bay ◽

Ice Dynamics ◽

Probabilistic Information ◽

Bay Area ◽

Sea Ice Dynamics ◽

Ice Conditions ◽

Reliable Knowledge ◽

Informative Content

Abstract. A reliable knowledge and assessment of the sea ice conditions and their evolution in time is a priority for numerous decision makers in the domains of coastal and offshore management and engineering as well as in commercial navigation. As of today, countless research projects aimed at both modelling and mapping past, actual and future sea ice conditions were realized using sea ice numerical models, statistical models, educated guesses or remote sensing imagery. From these research, reliable information helping to understand sea ice evolution in space and in time are available to stakeholders. However, no research has, as of today, assessed the evolution of the sea ice cover with a frequency modelling approach, by identifying the underlying theoretical distribution describing the sea ice behaviour at a given point in space and time. This project suggests the development of a probabilistic tool, named IcePAC, based on frequency modelling of historical 1978–2015 passive microwave sea ice concentrations maps from EUMETSAT OSI-409 product, to study the sea ice spatiotemporal behaviour in the waters of the Hudson Bay System in Northeastern Canada. Pixel scale models are based on the generalized Beta distribution and generated at a weekly temporal resolution. Results showed coherent with the Canadian Ice Service 1980–2010 Sea Ice Climatic Atlas average freeze-up and meltdown dates for numerous coastal communities in the study area and showed that it is possible to evaluate a range of plausible events, such as the shortest and longest probable ice free season duration, for any given location on the simulation domain. This innovative research opens a path towards various analyses on sea ice dynamics that would gain in informative content and value by relying on the kind of probabilistic information and simulation data available from the IcePAC tool.

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