Effects of climate change on the Atlantic Heat Conveyor relevant to the UK

The Atlantic Heat Conveyor or Atlantic Meridional Overturning Circulation (AMOC) is a major factor in maintenance of the climate and marine environment of the UK. The AMOC is predicted to weaken in the coming century due to climate change. The AMOC is currently in a weakened state and the subpolar North Atlantic appears to be entering a cool (and fresh) state. However, record cold temperatures in 2015 were found to be driven largely by air–sea heat loss rather than reduced AMOC. Large biogeographical and climatic shifts are expected in response to this shift to cooler conditions. There is little support for the idea that the AMOC will abruptly shut down despite new ideas suggesting more plausible mechanisms related to a shutdown. Skill in predicting climate on decadal timescales can be derived from correct initialisation of AMOC in prediction systems hence increasing the capacity to manage, mitigate, and adapt to AMOC related climate changes

Meridional Heat and Salinity Transports and the Surface Freshwater Exchange Derived from the OSNAP (Overturning in the Subpolar North Atlantic Program) Array between August 2014 and May 2018

Data from the full OSNAP array for the first 4 years between 2014 and 2018 have been used to produce the 30-day mean meridional heat (MHT) and salinity transports (MST), and the derived surface freshwater (FW) exchange time series.Related article: Observation-based estimates of heat and freshwater exchanges from the subtropical North Atlantic to the ArcticAn international effort, Overturning in the Subpolar North Atlantic Program (OSNAP), is a partnership among oceanographers from the US, UK, Germany, the Netherlands, Canada and China whose goal is to measure and understand what drives the subpolar overturning circulation and its associated property exchanges. OSNAP is consisted of more than 53 moorings that stretch from Labrador to Greenland to Scotland, providing a continuous record of the full water column, trans-basin velocity, temperature and salinity in the subpolar North Atlantic. Data from the full OSNAP array for the first 4 years between 2014 and 2018 have been used to produce the 30-day mean meridional heat (MHT) and salinity transports (MST), and the derived surface freshwater (FW) exchange time series.National Science Foundation Award Number 194833