The Environment of the Arctic: Climate, Ocean and Sea Ice (TEA-COSI)

Lead Research Organisation: National Oceanography Centre
Department Name: Science and Technology

Abstract

Look at a map of the world and find the Shetland Islands. Follow the 60 degrees north latitude circle eastwards. You pass through St. Petersburg, the Ural Mountains, Siberia, the Bering Sea, Alaska, northern Canada, the southern tip of Greenland, then back to the Shetlands. All these places are cold, harsh environments, particularly in winter, except the Shetlands, which is wet and windy but quite mild all year. This is because in the UK we benefit from heat brought northwards by the Atlantic Ocean in a current called the Conveyor Belt. This current is driven by surface water being made to sink by the extreme cold in and around the Arctic. It returns southwards through the Atlantic at great depths. Scientists think it is possible that the Conveyor Belt could slow down or stop, and if it did, the UK would get much colder.

We know the planet has been warming for the last century or more, and we think this is due to the Greenhouse Effect. Burning fossil fuels puts a lot of carbon dioxide into the atmosphere, which stops heat from leaving the Earth, like the glass in a greenhouse. In a warming world, ice melts faster, and there is a lot of ice on the Earth: ice caps on Greenland and Antarctica, sea ice in the Arctic and Antarctic Oceans, glaciers in high mountains. And we know that the Arctic is the fastest-warming part of the planet. This causes extra amounts of fresh water to flow into the oceans. Now this fresh water can affect the Conveyor Belt by acting like a lid of water too light to sink, so the Conveyor Belt stops.

What is the chance of this happening? We do not know, because there is much we do not understand about how the Arctic Ocean works. You need a powerful icebreaker to get into the Arctic Ocean, and that's only really possible in the summer, because in winter the sea ice thickens and the weather is bad. Scientists all over the world agree that the Arctic Ocean is important because it contains a lot of freshwater, which is why, although it is difficult to make measurements in the Arctic, the UK's Natural Environment Research Council has decided to fund a programme of scientific research in the Arctic.

We want to be able to make better predictions of how the Arctic climate will change during the 21st century, so this project will help improve our ability to make these predictions. We will do this by improving the way that computer models of the Earth's climate represent the Arctic. We are going to treat the Arctic Ocean as a box, with a top, a bottom, sides and an interior, and we're going to examine all these parts of the box using measurements from space, from ships, from instruments moored to the sea bed, and from robotic sensors attached to drifting sea ice. We'll use all these measurements together to improve the scientific equations within the computer models, and then we'll run the models into the future to create better predictions not just of the Arctic, but of how changes in the Arctic might influence UK, European and global climate. With better predictions, we can make better plans for the future.

Planned Impact

The academic beneficiaries will be UK, Arctic and global climate scientists. We specifically included the UK Meteorological Office's Hadley Centre early in the planning for this project, and, as major project collaborators, we will fund part of their work in order to help keep the Hadley Centre at the forefront of the global climate modelling community.

The UK government departments that will benefit directly from this project are the Department of Energy and Climate Change (DECC), the Department of Environment, Food and Rural Affairs (DEFRA), the Foreign and Commonwealth Office (FCO), and the Department of Transport (DfT). DECC are responsible for advising the UK government on climate risks and developing mitigation strategies at UK, European and international scales and for international adaptation. DEFRA is responsible for advising on UK adaptation strategies. The FCO are responsible for developing and shaping the UK's relationship with Arctic-rim nations and the forward look of this strategy. The DfT are tasked with ensuring that the UK's shipping/ports are operated in an efficient manner, and that UK shipping remains a globally competitive industry in the future. All these government departments will benefit directly from an improvement in UK capability to predict Arctic climate through the 21st century.

We will maximise the project's impact and achieve the project's goals for knowledge exchange through early and continued stakeholder engagement in consultation with the NERC Arctic Office, the Arctic programme management, and via planned activities within the project itself.

As measures of success, we will attend international science meetings (as normal). We will also catalogue the use of the Project's science findings in assisting government decisions and policy, in collaboration with nominated contacts in the relevant departments, and we will record the utilisation of project results in adjustments and modifications to Hadley Centre models and modelling approaches. We plan an open end-project meeting aimed at the scientific and stakeholder communities. Its success will be measured by the extent to which it attracts informed and wide user and scientist attendance.

Publications

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Aksenov Y (2016) Arctic pathways of Pacific Water: Arctic Ocean Model Intercomparison experiments. in Journal of geophysical research. Oceans

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Aksenov Y (2011) The Arctic Circumpolar Boundary Current in Journal of Geophysical Research

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Alexeev V (2011) Fate of Early 2000s Arctic Warm Water Pulse in Bulletin of the American Meteorological Society

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Armitage T (2018) Arctic Sea Level and Surface Circulation Response to the Arctic Oscillation in Geophysical Research Letters

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Armitage T (2017) Arctic Ocean surface geostrophic circulation 2003-2014 in The Cryosphere

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Bacon S (2014) Seasonal variability of the East Greenland Coastal Current in Journal of Geophysical Research: Oceans

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Bacon S (2015) Arctic mass, freshwater and heat fluxes: methods and modelled seasonal variability. in Philosophical transactions. Series A, Mathematical, physical, and engineering sciences

 
Description Current speeds in the Arctic Ocean are very low because for much of the time, it has a "lid" of sea ice, which insulates the ocean from the influence of the atmosphere - so it is hard for winds to push the seawater around. We have found that the changing sea ice conditions are causing the ocean currents to speed up, because with reduced sea ice, firstly the winds can "grip" the sea surface directly, and secondly, the ice is "unlocked", and because it is rough, it actually helps the winds to grip the ocean.

Now this acceleration of the ocean currents may have a second consequence: it may increase ocean turbulent mixing rates. This is important because there is a sub-surface layer of (relatively) warm water, sandwiched between a near-surface layer of cold and very fresh water, and a very deep, cold and dense layer. With fast currents, we expect greater turbulent mixing in the ocean, and it is possible that the sub-surface heat may be "mixed up" to the surface in the future. If it does, this could impact both the sea ice itself - more of it may melt, and for longer in the year - and the Arctic atmosphere. If the Arctic atmosphere warms faster, this may have an impact in mid-latitudes (including the UK), with our weather seeing more extremes, for example of temperature and rainfall.

These results (on spin-up and mixing) have been published in Nature Geoscience: Giles et al. 2012 and Rippeth et al. 2015.
Exploitation Route More research is needed to include the relevant turbulent mixing process in ice-ocean and climate models. Improvements in climate predictions will clarify the future impact of these Arctic processes on UK (and north-west European and North American) climate.
Sectors Environment,Government, Democracy and Justice,Transport

 
Description The PI was a witness to a House of Lords Select Committee enquiry on the Arctic in 2014. The PI also contributed to a Lloyd's of London / Chatham House report "Arctic Opening: Opportunity and Risk in the High North" in 2012. The PI contributed to a 4-day Royal Society meeting on the Arctic (lead organiser & project Co-I Feltham, U Reading), which saw global interest. NOC researcher Aksenov published on Arctic shipping futures (Aksenov et al., Marine Policy 2017).
First Year Of Impact 2012
Sector Environment,Financial Services, and Management Consultancy,Government, Democracy and Justice
 
Description House of Lords Arctic Committee: Witness
Geographic Reach Multiple continents/international 
Policy Influence Type Contribution to a national consultation/review
URL http://www.parliament.uk/business/committees/committees-a-z/lords-select/arcticcom/