DYNamics and predictability of the Atlantic Meridional Overturning and Climate (DYNAMOC)

Lead Research Organisation: NATIONAL OCEANOGRAPHY CENTRE
Department Name: Science and Technology

Abstract

The 'Atlantic Meridional Overturning Circulation', or AMOC, describes a large scale circulation of the North Atlantic Ocean which carries warm surface waters northward and cooler deeper waters southwards. This circulation carries huge amounts of heat, and variations in its strength can have a substantial influence on European climate. The DYNAMOC project aims to improve understanding of how this circulation has varied in the past and how it has affected climate, and also to assess the potential for useful predictions months to years ahead.

DYNAMOC will make use of new advanced computer simulations and forecasting systems which are able to simulate the AMOC in unprecedented detail. It will also make use of the RAPID observations of the AMOC strength at 26 degrees North, available since 2004, as a benchmark for testing the models and predictions. The research will test some specific hypotheses about how the AMOC works, how it is changing now. It will investigate how a slow down or speed up in the AMOC affects summers and winters in the UK and other countries. DYNAMOC will provide an assessment of the likely behaviour of the AMOC, and its impacts on climate, over the next decade. It will also produce recommendations for improving forecasting systems in the future.

DYNAMOC is a collaboration between the National Centre for Atmospheric Science at the University of Reading, the National Oceanography Centre and the UK Met Office.

Planned Impact

The beneficiaries of DYNAMOC will include:

1. Government Departments: (e.g. DECC, Defra and DFID, cabinet office) who are customers for Met Office seasonal-to-decadal forecasts and will benefit from improved forecasts. Furthermore, because the AMOC is one of the major mechanisms via which abrupt climate change may take place over the N Atlantic it is of extreme relevance to UK policymakers. DYNAMOC will provide new insights into the likelihood of a significant slowdown in the AMOC in the near term, and the likely impacts on the climate of Europe and other regions.

2. Businesses: seasonal forecasts are of increasing interest to businesses affected by weather and climate risks. The energy industry in particular requires information about future weather to manage supply and demand. Businesses will benefit from improved forecasts and specific advice concerning potential future changes in the AMOC and the likely consequences for businesses.

3. Met Office (MO): DYNAMOC outcomes will benefit the Met Office by i) Improving understanding of the role of the AMOC in climate variability and predictability and the representation of the relevant processes in the Met Office's models; ii) Assessing MO seasonal-to-decadal predictions and identifying opportunities for improvement; iii) Assessing the impact of the RAPID array observations on predictions.

4. International Customers: will benefit from the improved quality of the Met Office contribution to the coordinated international dissemination of seasonal forecasts (www.wmolc.org)

5. NERC: DYNAMOC outcomes will affect NERC's strategy through the project's input into the international review of the RAPID array in 2018.

6. General Public: Climate variability, such as droughts and flooding are of interest to the general public, but the AMOC's role in climate variability is still uncertain. DYNAMOC will engage the public on the AMOC's role in regional variability that affects the UK.

7. Trained Staff: DYNAMOC will train scientists in climate research and to engage with the public.

Publications

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Pickering M (2017) The impact of future sea-level rise on the global tides in Continental Shelf Research

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Hirschi J (2020) The Atlantic Meridional Overturning Circulation in High-Resolution Models in Journal of Geophysical Research: Oceans

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Hirschi J (2019) Loop Current Variability as Trigger of Coherent Gulf Stream Transport Anomalies in Journal of Physical Oceanography

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Hallam S (2019) Ocean precursors to the extreme Atlantic 2017 hurricane season in Nature Communications

 
Description The simulation using a high resolution ocean model (1/12°) has been extended closer to present and now simulates the years 1978 to 2015 has shown a greatly improved ability to simulate North Atlantic ocean currents at the heart of the project. In addition to this simulation we performed an ensemble of simulations with perturbed initial conditions (perturbations in 2007 and 2009). This provides us with a framework to better understand the extent to which the ocean circulation is directly forced through the atmosphere vs chaotic ocean variability. Our results suggest that up to 30% of the variability occurring in the Atlantic meridional overturning circulation is likely to be chaotic i.e. linked to processes that cannot directly be predicted from the atmospheric forcing alone (e.g. ocean mesoscale eddies). An important new finding is the link between the Atlantic meridional overturning circulation (AMOC) at 26.5N and sea surface temperatures (SSTs). Our results show that changes in the AMOC precede de development of anomalous SSTs in the subtropical and mid-latitude North Atlantic by 3-5 months. This opens to prospect of the RAPID AMOC timeseries at 26.5N to be used as an SST precursor. Another important result concerns multidecadal links between the Atlantic multidecadal oscillation (AMO) and the North Atlantic Oscillation (NAO). Positive and negative phases of the AMO are characterised by warmer and colder temperatures over much of the North Atlantic. Our research has shown that such temperature changes tend to precede changes in the NAO by about 5 years suggesting that it is the ocean that is driving the NAO on multidecadal timescales.
Exploitation Route The model described above will be the key tool to improve our understanding of the processes governing the variability of the Atlantic meridional overturning circulation. All the data of our model simulations are available on the JASMIN data server and therefore available to scientists from other research institutions. Our study linking AMOC observations to SST anomalies is to our knowledge the first concrete attempt to use the AMOC observations from 26.5N as a predictor for a climatically crucial quantity (SSTs). Even though this has not happened yet there could be some potential to use this approach to support forecasting of Atlantic hurricanes. One of the regions where we find the highest correlation between AMOC and SSTs is the mean development region for Atlantic hurricanes.
Sectors Environment

Other

 
Description Exploring and Predicting the Ocean Conveyor (EPOC)
Amount € 8,000,000 (EUR)
Funding ID UKRI 10038003 (Funding is coming via UKRI since EU and UK negotiations were at stalemate when EPOC was awarded in 2022). 
Organisation European Commission 
Sector Public
Country European Union (EU)
Start 11/2022 
End 11/2027
 
Title Eddy-resolving simulation 
Description Performance of a new, long global ocean simulation at 1/12° (NEMO ocean model in ORCA12 configuration). The simulation covers the period from 1958 to 2014. 
Type Of Material Improvements to research infrastructure 
Provided To Others? No  
Impact This simulation will provide with a unique opportunity to improve our understanding of the mechanisms behind the variability of the North Atlantic Meridional Overturning circulation. 
 
Description Met Office - DYNAMOC 
Organisation Meteorological Office UK
Country United Kingdom 
Sector Academic/University 
PI Contribution NOC has carried out a new simulation (global NEMO 1/12°) and output is available to project partners (via JASMIN data server)
Collaborator Contribution The Met Office provided access to output from its forecasting Systems (via JASMIN data server).
Impact Reciprocal access to data (NEMO 1/12° global ocean model simulation; output from forecasting systems)
Start Year 2015
 
Description Article - Spektrum der Wissenschaft (Magazine) 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact I provided background information for an article in "Spektrum der Wissenschaft" (the nr 1 popular science magazine in Germany) about the influence of the warm Atlantic ocean temperatures on our weather and climate.
Year(s) Of Engagement Activity 2023
URL https://www.spektrum.de/news/was-der-warme-atlantik-mit-dem-wetter-macht/2154948
 
Description Associated Press 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Responded to a request from Associated Press about an article on a possible AMOC collapse. My comments were quoted on multiple media cites on all continents.
Year(s) Of Engagement Activity 2024
URL https://apnews.com/article/atlantic-collapse-climate-change-abrupt-tipping-point-954f5b030b8510551ab...
 
Description CLIVAR talk 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Presentation given in the framework of the CLIVAR seminar series on the Atlantic meridional overturning circulation.
Year(s) Of Engagement Activity 2021
URL https://youtu.be/CcQ4qCV2L_U
 
Description Comment for CNN 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Comments for CNN on recent study suggesting a 2.4 Ma climate cycle linked to orbital influence from Mars:
Year(s) Of Engagement Activity 2024
URL https://edition.cnn.com/2024/03/12/climate/mars-earth-ocean-currents-climate-intl/index.html
 
Description Contributed to BBC interview (50th anniversary discovery) 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I was asked to comment on the purpose of some instrumentation that would be deployed in order to help monitoring the Atlantic meridional overturning in real time.
Year(s) Of Engagement Activity 2015
URL https://www.facebook.com/bbcbreakfast/videos/1185374644810005/
 
Description Guardian article - 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Responded to a request from the Guardian about the record high ocean temperatures in 2024. My quotes were included in the article and were widely noted.
Year(s) Of Engagement Activity 2024
URL https://www.theguardian.com/environment/2024/feb/17/february-on-course-to-break-unprecedented-number...
 
Description Interview - Neu Zürcher Zeitung 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Interview given to journalist Sven Titz who works for the Neue Zürcher Zeitung.
Year(s) Of Engagement Activity 2020
URL https://www.nzz.ch/wissenschaft/golfstrom-noch-zeigt-die-atlantikzirkulation-keine-schwaeche-ld.1583...
 
Description Interview New York Times 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Interview with the NY Times journalist Moises Velasquez-Manoff to discuss a possible slowdown of the Atlantic meridional overturning circulation. Given the large readership of the NY Times I suppose that many people will have read the article even if I cannot put a number on it. More than 400 people have commented though, so it is fair to assume that many thousands read the piece. I think this article sparked quite a bit of discussion in the public but it also highlighted that even within the scientific community there are differing views regarding the AMOC, it's slowdown and likely climatic impacts.
Year(s) Of Engagement Activity 2021
URL https://www.nytimes.com/interactive/2021/03/02/climate/atlantic-ocean-climate-change.html
 
Description Interview for Bloomberg 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact I discussed the warm ocean temperatures of 2023 which journalist Jack Whittles.
Year(s) Of Engagement Activity 2023
URL https://www.bloomberg.com/news/articles/2023-08-04/summer-heat-waves-are-far-from-over-in-the-medite...
 
Description Interview for CNN 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact I provided comments on an article suggestion a possible AMOC collapse in 2024 to Laura Paddison from CNN. My comments were quoted on multiple sites.
Year(s) Of Engagement Activity 2023
URL https://edition.cnn.com/2024/02/09/climate/atlantic-circulation-collapse-weather-climate/index.html
 
Description Interview for Channel 5 news: Talked about the high global ocean temperatures in 2023 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I was interviewed by Channel 5 to talk about the record high ocean surface temperatures recorded in August 2023.
Year(s) Of Engagement Activity 2023
URL https://twitter.com/5_News/status/1687528046373306374
 
Description Invited Seminar - University of Berne (Switzerland) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact About 100-150 people attended my seminar at the University of Berne on 21st October 2015
Year(s) Of Engagement Activity 2015
 
Description Invited talk at the Isaac Newton Institute, Cambridge 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Overview presentation highlighting the current state of the art and challenges in ocean and climate modelling
Year(s) Of Engagement Activity 2022
URL https://gateway.newton.ac.uk/presentation/2022-10-24/37177
 
Description Invited talk at the University of Bern, Switzerland 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact In my talk I presented to progress made over the last few decades in our ability to simulate the Atlantic Meridional Overturning circulation. The seminar was attended by about 50 people.
Year(s) Of Engagement Activity 2022
 
Description Podcast: Into the Blue 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact The goal of the podcast was to discuss the high ocean temperatures of 2023, their link to El Niño, and an outlook for 2024.
Year(s) Of Engagement Activity 2023
URL https://www.youtube.com/watch?v=5er8CFhc7Io&t=1shttps://www.youtube.com/watch?v=5er8CFhc7Io&t=1s
 
Description Presentation - Southwestern Arms 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Around 30-40 people attended my presentation in the Southwestern Arms Pub (Southampton)
Year(s) Of Engagement Activity 2015