The Changing North Atlantic Ocean and its Impact on Climate

Photo: Ocean view

The Atlantic Meridional Overturning Circulation (AMOC) is a key component of the global climate system, and dominates northward ocean heat transport over most of the Atlantic. The Subpolar North Atlantic is the region where the AMOC is actively shaped through a combination of surface fluxes of heat, freshwater and momentum.

There is increasing evidence that knowledge of the Subpolar North Atlantic is important for decadal climate prediction. Through collaboration with the National Science Foundation, this programme will extend the observations of the OSNAP to a decade and will support the utilisation of the observations for use in science and policy predictions.

This programme is supported by the Natural Environment Research Council (NERC), through the Fund for International Collaboration (FIC), and the US National Science Foundation (NSF).

Announcement of Opportunity: The Changing North Atlantic and its Impact on Climate

Closing date: 21 Nov
2019

18 Sep 2019

Proposals are invited for a new joint UK-US research programme that will take advantage of the data arising from the joint UK-US OSNAP array, to improve understanding and models of the Subpolar North Atlantic and its impacts. The programme is supported by the Natural Environment Research Council (NERC) and the US National Science Foundation (NSF).

The Atlantic Meridional Overturning Circulation (AMOC) is a key component of the global climate system, and dominates northward ocean heat transport over most of the Atlantic. The Subpolar North Atlantic is the region where the AMOC is actively shaped through a combination of surface fluxes of heat, freshwater and momentum.  The AMOC is usually defined as the zonally-integrated meridional flow, as a function of latitude and depth and is characterized by a northwards flow of warm, salty upper ocean waters and a return southwards flow of cool, fresher, deep waters; however, this characterisation is over simplistic in the Subpolar North Atlantic where the circulation is three-dimensional and interacts in a complex way with the bathymetry. The Subpolar North Atlantic contains three major current systems: the North Atlantic Current, the Deep Western Boundary Current (DWBC), and the Western Boundary Current system. In order to measure the AMOC in the Subpolar North Atlantic the OSNAP international partners deployed the OSNAP array – a trans-basin observing system – in 2014. 

It is known that the time-scales of variability of the Subpolar North Atlantic span sub-seasonal to a decade, and that it can take up to a decade for the Subpolar North Atlantic to impact the overturning at lower latitudes. As there is increasing evidence that knowledge of the Subpolar North Atlantic is important for decadal climate prediction, and so observations of the Subpolar North Atlantic over a similar timescale are therefore critical if such decadal climate prediction are to prove a useful tool both for science and for policy decisions, and to assess the performance of the climate models’ representation of the Subpolar North Atlantic in terms of fidelity. The major changes occurring in the Subpolar North Atlantic at the moment provide an ideal opportunity to understand the cause and impact of a major signal in the observations and therefore to study the relationship between the AMOC and local and remote processes.

This programme will extend the OSNAP observational period to a decade, and through collaboration with the US and by utilising the OSNAP observations, this programme aims to address two Challenges:

Challenge 1: Combine observations and ocean-climate models in order to deliver a step change in quantitative understanding of processes that matter for subpolar variability.

Challenge 2: Determine the impacts of subpolar variability on the ocean-atmosphere-ice system.

Timing

2020 - 2023

Can I apply for a grant?

Not at this time.

Budget

£2.8 million - UK

$500,000 per project limit for US proposals