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Details of Award

NERC Reference : NE/T013494/1

SNAP-DRAGON: Subpolar North Atlantic Processes - Dynamics and pRedictability of vAriability in Gyre and OverturNing

Grant Award

Principal Investigator:
Professor HL Johnson, University of Oxford, Earth Sciences
Co-Investigator:
Dr TJ Woollings, University of Oxford, Oxford Physics
Co-Investigator:
Professor RG Williams, University of Liverpool, Earth, Ocean and Ecological Sciences
Co-Investigator:
Professor SA Cunningham, Scottish Association For Marine Science, Dunstaffnage Marine Laboratory
Co-Investigator:
Dr D Ferreira, University of Reading, Meteorology
Co-Investigator:
Professor DP Marshall, University of Oxford, Oxford Physics
Co-Investigator:
Professor J Robson, University of Reading, National Centre for Atmospheric Science
Science Area:
Atmospheric
Marine
Overall Classification:
Unknown
ENRIs:
Global Change
Science Topics:
Climate modelling
Climate variability
Deep ocean circulation
Ocean atmosphere interaction
Ocean modelling
Regional climate
Sea surface temperature
Sea-ice processes
Surface ocean circulation
Climate & Climate Change
Atmospheric circulation
Climate modelling
Ocean circulation
Ocean modelling
Ocean - Atmosphere Interact.
Sea ice
Sea surface temperature
Data assimilation
Deep convection
Deep ocean circulation
Heat transport
Meridional overturning circ
Ocean modelling
Oceanic eddies
Sea ice
Thermohaline circulation
Western boundary currents
Ocean Circulation
Water mass analysis
Abstract:
SNAP-DRAGON will produce a step change in our understanding of the processes that link atmospheric changes to subpolar ocean variability, their implications for ocean and climate predictability in this region, and the degree to which we can trust their representation in climate models. The subpolar North Atlantic Ocean, stretching between the UK, Greenland and Canada, plays a crucial role in local and global climate. This is the critical region where much of the warm water flowing northward in the upper North Atlantic releases its heat to the atmosphere and is converted to cold, dense water, before flowing southward again at depth in what is known as the Atlantic overturning circulation. The huge amount of heat this circulation carries northward and releases to the atmosphere impacts the storm track that determines the weather over western Europe. The overturning circulation also has profound implications for African rainfall and hurricane statistics via its effect on sea surface temperatures at lower latitudes. In addition, the sinking of water in the subpolar region ventilates the deep ocean, transferring heat and carbon away from the surface and moderating the impact of anthropogenic greenhouse gases on surface temperature. Any warm water which does not sink in the subpolar region recirculates or carries its heat further north towards the Arctic, influencing sea-ice conditions and polar marine ecosystems before it too sinks and flows south. Recently, the first ever observations of the overturning circulation in the subpolar North Atlantic have been made by the Overturning in the Subpolar North Atlantic Programme (OSNAP, www.o-snap.org). These have revealed large amplitude variations in the overturning, but raised questions about the locations and processes that give rise to this variability, and its likely impact on surface ocean conditions and climate. Representing this region properly in climate models is essential if we are to make useful climate predictions on seasonal, interannual, decadal and longer timescales. However, the current generation of models struggle to represent the processes we know to be important here, and disagree with the observations on the locations in which warm water is transformed into dense water. The disagreements limit our confidence in model predictions. We cannot assess model performance properly because we do not understand all the links between atmospheric conditions and ocean circulation variability. In SNAP-DRAGON we will combine OSNAP and other observations with numerical models that can represent small-scale processes to work out what causes variations in subpolar ocean circulation. Once we know which processes are most important and how they work, we will be able to establish what climate models are getting wrong, and suggest improvements. This will improve predictions of ocean and climate variability in the subpolar North Atlantic and beyond. We will investigate how cold, dense waters find their way into the boundary currents that export them to the south. We will establish the role that winds play, which is likely more complicated than we have assumed in the past. And we will determine the impact on overturning variability of changes in freshwater export from the Arctic and Greenland. To characterize and quantify these key processes, in addition to using ocean observations, we will perform "What if?" experiments in ocean models, asking questions such as: what happens to the subpolar ocean circulation if the atmospheric jet stream over the Atlantic shifts or strengthens? We will use statistical methods more common in weather forecasting to figure out how subpolar ocean properties and overturning connect to potentially predictable larger-scale atmospheric circulation patterns. And we will employ innovative ways of combining models with observations to determine a best estimate of the evolution of the subpolar North Atlantic over the OSNAP observation period.
Period of Award:
1 Sep 2020 - 30 Apr 2024
Value:
£1,216,623 Lead Split Award
Authorised funds only
NERC Reference:
NE/T013494/1
Grant Stage:
Completed
Scheme:
Directed (Research Programmes)
Grant Status:
Closed

This grant award has a total value of £1,216,623  

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FDAB - Financial Details (Award breakdown by headings)

DI - Other CostsIndirect - Indirect CostsDA - InvestigatorsDA - Estate CostsDI - StaffDI - T&SDA - Other Directly Allocated
£23,082£447,161£150,484£132,290£396,982£60,978£5,648

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