scholarly journals How reversible is sea ice loss?

2012 ◽  
Vol 6 (1) ◽  
pp. 193-198 ◽  
Author(s):  
J. K. Ridley ◽  
J. A. Lowe ◽  
H. T. Hewitt
Keyword(s):  
Sea Ice ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
Rate Of Change ◽  
Atmospheric Co2 ◽  
Asymmetric Behaviour ◽  
The Impact

Abstract. It is well accepted that increasing atmospheric CO2 results in global warming, leading to a decline in polar sea ice area. Here, the specific question of whether there is a tipping point in the sea ice cover is investigated. The global climate model HadCM3 is used to map the trajectory of sea ice area under idealised scenarios. The atmospheric CO2 is first ramped up to four times pre-industrial levels (4 × CO2), then ramped down to pre-industrial levels. We also examine the impact of stabilising climate at 4 × CO2 prior to ramping CO2 down to pre-industrial levels. Against global mean temperature, Arctic sea ice area is reversible, while the Antarctic sea ice shows some asymmetric behaviour – its rate of change slower, with falling temperatures, than its rate of change with rising temperatures. However, we show that the asymmetric behaviour is driven by hemispherical differences in temperature change between transient and stabilisation periods. We find no irreversible behaviour in the sea ice cover.

scholarly journals How reversible is sea ice loss?

2011 ◽  
Vol 5 (5) ◽  
pp. 2349-2363 ◽  
Author(s):  
J. K. Ridley ◽  
J. A. Lowe ◽  
H. T. Hewitt
Keyword(s):  
Sea Ice ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
Rate Of Change ◽  
Atmospheric Co2 ◽  
Antarctic Sea Ice ◽  
The Impact

Abstract. It is well accepted that increasing atmospheric CO2 results in global warming, leading to a decline in polar sea ice area. Here, the specific question of whether there is a tipping point in the sea ice cover is investigated. The global climate model HadCM3, is used to map the trajectory of sea ice area under idealised scenarios. The atmospheric CO2 is first ramped up to four times pre-industrial levels (4 × CO2) then ramped down back to pre-industrial levels. We also examine the impact of stabilising climate at 4 × CO2 prior to ramping CO2 down to pre-industrial levels. Against global mean temperature Arctic sea ice area has little hysteresis while the Antarctic sea ice shows significant hysteresis – its rate of change slower, with falling temperatures, than its rate of change with rising temperatures. However, we show that the driver of the hysteresis is the hemispherical differences in temperature change between transient and stabilisation periods. We find no irreversible behaviour in the sea ice cover.

Interactions between ocean heat transport and Arctic sea ice

2020 ◽  
Author(s):  
David Docquier ◽  
Ramon Fuentes-Franco ◽  
Klaus Wyser ◽  
Torben Koenigk
Keyword(s):  
Sea Ice ◽  
Heat Transport ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Arctic Sea Ice ◽  
Ocean Heat Transport ◽  
Arctic Sea ◽  
Fast Pace ◽  
Area And Volume

<p>Arctic sea ice has been retreating at fast pace in the last decades, with potential impacts on the weather and climate at mid and high latitudes, as well as the biosphere and society. Sea-ice loss is driven by anthropogenic global warming, atmospheric circulation changes, climate feedbacks, and ocean heat transport. To date, no clear consensus regarding the detailed impact of ocean heat transport on Arctic sea ice exists. Previous observational and modeling studies show that the poleward Atlantic Ocean heat transport and Arctic sea-ice area and volume are generally anti-correlated, suggesting a decrease in sea-ice area and volume with larger ocean heat transport. In turn, the changing sea ice may also affect ocean heat transport, but this effect has been much less studied. Our study explores the two-way interactions between ocean heat transport and Arctic sea ice. We use the EC-Earth global climate model, coupling the atmosphere and ocean, and perform different sensitivity experiments to gain insights into these interactions. The mechanisms by which ocean heat transport and Arctic sea ice interact are analyzed, and compared to observations. This study provides a way to better constrain model projections of Arctic sea ice, based on the relationships between ocean heat transport and Arctic sea ice.</p>

scholarly journals Marginal ice zone fraction benchmarks sea ice and climate model skill

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Christopher Horvat
Keyword(s):  
Sea Ice ◽  
Climate Models ◽  
Climate Model ◽  
Global Climate ◽  
Internal Variability ◽  
Arctic Sea Ice ◽  
Global Climate Models ◽  
Global Mean Temperature ◽  
Marginal Ice Zone ◽  
The Impact

AbstractGlobal climate models (GCMs) consistently underestimate the response of September Arctic sea-ice area (SIA) to warming. Modeled SIA losses are highly correlated to global mean temperature increases, making it challenging to gauge if improvements in modeled sea ice derive from improved sea-ice models or from improvements in forcing driven by other GCM components. I use a set of five large GCM ensembles, and CMIP6 simulations, to quantify GCM internal variability and variability between GCMs from 1979–2014, showing modern GCMs do not plausibly estimate the response of SIA to warming in all months. I identify the marginal ice zone fraction (MIZF) as a metric that is less correlated to warming, has a response plausibly simulated from January–September (but not October–December), and has highly variable future projections across GCMs. These qualities make MIZF useful for evaluating the impact of sea-ice model changes on past, present, and projected sea-ice state.

Oil exploration and sea ice projections in the Arctic

Polar Record ◽  
2013 ◽  
Vol 51 (1) ◽  
pp. 91-106 ◽  
Author(s):  
Øistein Harsem ◽  
Knut Heen ◽  
J.M.P. Rodrigues ◽  
Terje Vassdal
Keyword(s):  
Sea Ice ◽  
Climate Model ◽  
Barents Sea ◽  
Global Climate ◽  
Global Climate Model ◽  
Ice Cover ◽  
The Arctic ◽  
Oil Exploration ◽  
Comparative Cost ◽  
The North

ABSTRACTThe aim of this study is to investigate how reduction in the sea ice cover may affect oil activity in the Arctic during the next 30 years. The Arctic is divided into 21 oil provinces. A multidisciplinary approach is applied drawing on both the comparative cost techniques as developed in location theory and sea ice cover projections. The comparative cost technique implies a systematic listing of cost differentials by oil provinces. The sea ice projections are based on the NCAR CCSM3 global climate model under the A1B and A2 emission scenarios. The article concludes that the north Norwegian Sea, and south and west Barents Sea will remain the most attractive areas for oil exploration in the coming 30 years. Furthermore, due to sea ice decline, the north and east Barents Sea and north and west Kara Sea will become more attractive. However, most Arctic provinces will remain high cost regions.

scholarly journals Interannual predictability of Arctic sea ice in a global climate model: regional contrasts and temporal evolution

2014 ◽  
Vol 43 (9-10) ◽  
pp. 2519-2538 ◽  
Author(s):  
Agathe Germe ◽  
Matthieu Chevallier ◽  
David Salas y Mélia ◽  
Emilia Sanchez-Gomez ◽  
Christophe Cassou
Keyword(s):  
Sea Ice ◽  
Climate Model ◽  
Temporal Evolution ◽  
Global Climate ◽  
Global Climate Model ◽  
Arctic Sea Ice ◽  
Arctic Sea

scholarly journals Investigating future changes in the volume budget of the Arctic sea ice in a coupled climate model

2018 ◽  
Vol 12 (9) ◽  
pp. 2855-2868 ◽  
Author(s):  
Ann Keen ◽  
Ed Blockley
Keyword(s):  
Sea Ice ◽  
21St Century ◽  
Climate Model ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Ice Growth ◽  
Basal Ice ◽  
Arctic Sea ◽  
The Impact

Abstract. We present a method for analysing changes in the modelled volume budget of the Arctic sea ice as the ice declines during the 21st century. We apply the method to the CMIP5 global coupled model HadGEM2-ES to evaluate how the budget components evolve under a range of different forcing scenarios. As the climate warms and the ice cover declines, the sea ice processes that change the most in HadGEM2-ES are summer melting at the top surface of the ice due to increased net downward radiation and basal melting due to extra heat from the warming ocean. There is also extra basal ice formation due to the thinning ice. However, the impact of these changes on the volume budget is affected by the declining ice cover. For example, as the autumn ice cover declines the volume of ice formed by basal growth declines as there is a reduced area over which this ice growth can occur. As a result, the biggest contribution to Arctic ice decline in HadGEM2-ES is the reduction in the total amount of basal ice growth during the autumn and early winter. Changes in the volume budget during the 21st century have a distinctive seasonal cycle, with processes contributing to ice decline occurring in May–June and September to November. During July and August the total amount of sea ice melt decreases, again due to the reducing ice cover. The choice of forcing scenario affects the rate of ice decline and the timing and magnitude of changes in the volume budget components. For the HadGEM2-ES model and for the range of scenarios considered for CMIP5, the mean changes in the volume budget depend strongly on the evolving ice area and are independent of the speed at which the ice cover declines.

scholarly journals Response of the Northern Hemisphere sea ice to greenhouse forcing in a global climate model

2001 ◽  
Vol 33 ◽  
pp. 513-520 ◽  
Author(s):  
Larissa Nazarenko ◽  
James Hansen ◽  
Nikolai Tausnev ◽  
Reto Ruedy
Keyword(s):  
Sea Ice ◽  
Northern Hemisphere ◽  
General Circulation ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Circulation Model ◽  
High Sensitivity ◽  
Ice Cover ◽  
Sea Ice Extent

AbstractThe Q.-flux Goddard Institute of Space Studies (GISS) global climate model, in which an atmospheric general circulation model is coupled to a mixed-layer ocean with specified horizontal heat transports, is used to simulate the transient and equilibrium climate response to a gradual increase of carbon dioxide (1% per year increase of CO2 to doubled CO2). The results indicate that the current GISS model has a high sensitivity with a global annual warming of about 4°C for doubled CO2 . Enhanced warming is found at higher latitudes near sea-ice margins due to retreat of sea ice in the greenhouse experiment. Surface warming is larger in winter than in summer, in part because of the reductions in ice cover and thickness that insulate the winter atmosphere from the ocean. The annual mean reduction of sea-ice cover due to doubled CO2 is about 30% for the Northern Hemisphere. The CO2 experiment has a 70% reduction of sea-ice area and 55% thinning of ice in August in the Northern Hemisphere. Noticeable reduction of sea-ice cover has been found in both historical records and satellite observations. The largest reduction of simulated sea-ice extent occurs in summer, consistent with observations.

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