scholarly journals Temperature, carbon dioxide and methane

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.

scholarly journals Temperature, carbon dioxide and methane

2021 ◽  
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.

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

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.

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

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

<p>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–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. </p>

scholarly journals Wave–sea-ice interactions in a brittle rheological framework

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.

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

2021 ◽  
Author(s):  
Guillaume Boutin ◽  
Einar Ólason ◽  
Pierre Rampal ◽  
Camille Lique ◽  
Claude Talandier ◽  
...  
Keyword(s):  
Sea Ice ◽  
Numerical Models ◽  
Coupled Model ◽  
Small Scale ◽  
Polar Regions ◽  
Fine Scale ◽  
Ice Dynamics ◽  
Damage Propagation ◽  
Sea Ice Dynamics ◽  
The Impact

<p>Sea ice is a key component of the earth’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. </p><p>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.</p>

scholarly journals Highly individualistic rates of plant phenological advance associated with arctic sea ice dynamics

2016 ◽  
Vol 12 (12) ◽  
pp. 20160332 ◽  
Author(s):  
Eric Post ◽  
Jeffrey Kerby ◽  
Christian Pedersen ◽  
Heidi Steltzer
Keyword(s):  
Sea Ice ◽  
Arctic Sea Ice ◽  
Sea Ice Extent ◽  
Ice Dynamics ◽  
Sea Ice Dynamics ◽  
Sea Ice Decline ◽  
Potential Contributor ◽  
Deciduous Shrubs ◽  
Low Arctic ◽  
Species Specific

We analysed 12 years of species-specific emergence dates of plants at a Low-Arctic site near Kangerlussuaq, Greenland to investigate associations with sea ice dynamics, a potential contributor to local temperature variation in near-coastal tundra. Species displayed highly variable rates of phenological advance, from a maximum of −2.55 ± 0.17 and −2.93 ± 0.51 d yr −1 among a graminoid and forb, respectively, to a minimum of −0.55 ± 0.19 d yr −1 or no advance at all in the two deciduous shrub species. Monthly Arctic-wide sea ice extent was a significant predictor of emergence timing in 10 of 14 species. Despite variation in rates of advance among species, these rates were generally greatest in the earliest emerging species, for which monthly sea ice extent was also the primary predictor of emergence. Variation among species in rates of phenological advance reshuffled the phenological community, with deciduous shrubs leafing out progressively later relative to forbs and graminoids. Because early species advanced more rapidly than late species, and because rates of advance were greatest in species for which emergence phenology was associated with sea ice dynamics, accelerating sea ice decline may contribute to further divergence between early- and late-emerging species in this community.

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