Value Of the Rapid array for climate predictions (VALOR)

Lead Research Organisation: University of Reading
Department Name: Meteorology

Abstract

The Atlantic Meridional Overturning Circulation (AMOC) involves a northward movement of warm surface waters balanced by a southward movement of cold deep waters. The net effect is to transport ~1PW of heat northwards. This heat is released to the atmosphere in mid-high latitudes, where it acts to warm the climate, notably in northern Europe. The future behaviour of the AMOC is an issue of major importance in climate prediction. Forecasts presented by the Intergovernmental Panel on Climate Change (IPCC) suggest that, in response to greenhouse gas forcing, the AMOC may slow down, reducing the northward transport of heat by the Atlantic Ocean, and leading to a cooling of northern Europe that could offset anthropogenic warming. Moreover, there is evidence from palaeoclimate records that the AMOC can undergo very rapid transitions such as a total shutdown within little more than a decade. It is possible that increasing levels of greenhouse gases could trigger such a rapid change with potentially serious consequences for societies in Europe and other regions surrounding the Atlantic basin. In the face of such risks, there is an obvious need for better, more quantitative, forecasts of the future behaviour of the AMOC. Such forecasts could provide early warning of possible rapid changes in the AMOC in future The RAPID array is a measurement system for observing the current state of the AMOC. Established in 2004, the array is providing direct and continuous measurements of the AMOC for the first time, and under the RAPID-WATCH programme these measurements will be maintained for a decade. The overarching goal of the VALOR project is to assess the value of these observations for predicting the future behaviour of the AMOC, and its impacts on climate. The project will explore a range of issues concerning the design of a potential AMOC prediction system. To achieve its goals VALOR will exploit the RAPID observations in a variety of ways. First the observations will be used as independent data to assess the quality of current ocean 'analyses' (An 'analysis' provides a quantitative description of the state of the ocean at a given time.). Next, they will be used to improve the analyses. Finally, they will be used to provide the starting conditions for a large set of 'hindcasts'. Hindcasts are predictions made from a date in the past, which only make use of information that would have been available at that date. These predictions can then be compared to what actually happened to assess prediction skill. VALOR will carry out a suite of hindcast experiments to quantify the extent to which the RAPID observations can improve the skill of predictions of the AMOC and its impacts on climate. An important dimension of the project is that it involves agencies who are directly involved in operational climate forecasting: the Met Office Hadley Centre (MOHC) and the European Centre for Medium Range Weather Forecasting. By involving these partners from the start the project will benefit from their experience and expertise, and the scientific advances achieved through the research will feed directly into better climate predictions.

Publications

10 25 50
 
Description The Atlantic Meridional Overturning Circulation (AMOC) is an important component of the climate system that transports heat northward in the Atlantic. Because of its important role in the northward heat transport, it is widely thought that slow variations in the strength of the AMOC contribute to the of decade-to-decade variations in surface climate over the North Atlantic sector. The overarching goal of the Value Of the Rapid array for climate predictions (VALOR) project is to improve our ability to predict changes in the AMOC and its climate impacts.



One focus of VALOR has been on using the observations from the RAPID array, which measures the strength of the AMOC at 26N, with models to improve our knowledge of the current state of the Atlantic. VALOR has shown that when care is taken, and specific AMOC-tailored methods used, the rapid data can be used in synergy with a model to improve our estimates of the large-scale ocean circulation - i.e. in so called ocean reanalyses. Importantly, by analysing the heat fluxes in the ocean reanalyses, VALOR has also highlighted an incorrect assumption in the calculation of the heat transport measured by the RAPID array. The implication is that observed northward heat flux was overestimated.



The VALOR project has also focused on quantifying the role of the AMOC variability on changes in North Atlantic climate in the past, and has provided persuasive evidence that the AMOC has indeed been associated with the evolution of North Atlantic climate. Such an impact is particularly clear for a rapid warming of the North Atlantic that occurred in the mid-1990s. By exploring decadal timescale predictions that start from an observed estimate of the ocean in the early 1990s, VALOR has shown that knowing the current state of the AMOC was key for successful predictions of the subpolar North Atlantic climate in the mid-1990s. Such successful predictions of the temperature of the North Atlantic have also been shown to allow some degree of predictability of the wider surface climate of Europe and North America. Thus, results from VALOR provide encouragement for the prospect of generating useful climate predictions of European climate into the next decade.
Exploitation Route New methods for including the RAPID array observations into seasonal-to-decadal predictions could be used by forecast centres to improve predictions. Partners for VALOR include the UK Met Office and the European Centre Medium-Range Weather Forecasts, thus increased understanding of important processes can be directly transferred to these centres through collaboration.



VALOR results to understand the important processes that govern the AMOC and climate variability in the wider Atlantic, and methods to assimilate the RAPID array observations are being published in peer reviewed journals and so will be available for use by the wider research community.
Sectors Environment

URL http://valor.nerc.ac.uk/
 
Description The European Centre for Medium-Range Weather Forecasts (ECMWF) is a integral partner in VALOR. Collaboration in VALOR has resulted in the ECMWF using the RAPID array observations as a validation tool for their ocean reanalyses.
Sector Cultural
Impact Types Cultural

 
Description Further funding from ERGODICS
Amount £608,499 (GBP)
Funding ID NE/J005894/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 07/2012 
End 04/2017
 
Description NERC National Capability Long Term Science - MultiCentre Programme: North Atlantic Climate System Integrated Study (ACSIS)
Amount £9,000,000 (GBP)
Funding ID NE/N018001/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 04/2016 
End 03/2021
 
Description NERC RAPID-AMOC program - DYNAMOC project
Amount £418,694 (GBP)
Funding ID NE/M005127/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 12/2014 
End 12/2017
 
Description NERC RAPID-AMOC program - RAMOC project
Amount £506,532 (GBP)
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 10/2014 
End 10/2018
 
Description North Atlantic Climate System Integrated Study (ACSIS programme) 
Organisation British Antarctic Survey
Country United Kingdom 
Sector Academic/University 
PI Contribution The North Atlantic Climate System Integrated Study (ACSIS programme) is a 5 year research programme led by NCAS (PI Rowan Sutton) and also involving: NOC, BAS, NCEO, PML, CPOM and the Met Office.
Collaborator Contribution Details at www.acsis.ac.uk and https://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-16-0266.1
Impact https://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-16-0266.1
Start Year 2016
 
Description North Atlantic Climate System Integrated Study (ACSIS programme) 
Organisation Meteorological Office UK
Country United Kingdom 
Sector Public 
PI Contribution The North Atlantic Climate System Integrated Study (ACSIS programme) is a 5 year research programme led by NCAS (PI Rowan Sutton) and also involving: NOC, BAS, NCEO, PML, CPOM and the Met Office.
Collaborator Contribution Details at www.acsis.ac.uk and https://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-16-0266.1
Impact https://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-16-0266.1
Start Year 2016
 
Description North Atlantic Climate System Integrated Study (ACSIS programme) 
Organisation National Centre for Earth Observation
Country United Kingdom 
Sector Academic/University 
PI Contribution The North Atlantic Climate System Integrated Study (ACSIS programme) is a 5 year research programme led by NCAS (PI Rowan Sutton) and also involving: NOC, BAS, NCEO, PML, CPOM and the Met Office.
Collaborator Contribution Details at www.acsis.ac.uk and https://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-16-0266.1
Impact https://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-16-0266.1
Start Year 2016
 
Description North Atlantic Climate System Integrated Study (ACSIS programme) 
Organisation National Oceanography Centre
Country United Kingdom 
Sector Academic/University 
PI Contribution The North Atlantic Climate System Integrated Study (ACSIS programme) is a 5 year research programme led by NCAS (PI Rowan Sutton) and also involving: NOC, BAS, NCEO, PML, CPOM and the Met Office.
Collaborator Contribution Details at www.acsis.ac.uk and https://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-16-0266.1
Impact https://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-16-0266.1
Start Year 2016
 
Description North Atlantic Climate System Integrated Study (ACSIS programme) 
Organisation Plymouth Marine Laboratory
Country United Kingdom 
Sector Academic/University 
PI Contribution The North Atlantic Climate System Integrated Study (ACSIS programme) is a 5 year research programme led by NCAS (PI Rowan Sutton) and also involving: NOC, BAS, NCEO, PML, CPOM and the Met Office.
Collaborator Contribution Details at www.acsis.ac.uk and https://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-16-0266.1
Impact https://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-16-0266.1
Start Year 2016
 
Description Partnership with the Met Office Hadley Centre 
Organisation Meteorological Office UK
Country United Kingdom 
Sector Public 
PI Contribution Strategic partnership in high resolution climate modelling, decadal climate prediction and other areas
Collaborator Contribution Strategic partnership in high resolution climate modelling, decadal climate prediction and other areas
Impact Publications. Improvements to Met Office decadal prediction system. Collaboration with the insurance businesses on climate risk assessment.
 
Description IOP talk on the Atlantics role in climate variability and change 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Jon Robson gave a talk to the Institute of Physics East Midlands branch on the role of the North Atlantic Ocean in climate variability and change. The audience was non-specialist, but all with a physics background and included undergraduate and post-graduate students. The talk sparked significant discussion and interest afterwards. Jon has received interest in repeating the talk in other IOP regional groups.
Year(s) Of Engagement Activity 2014