Recent and Ongoing Changes in the High-latitude Atlantic (ROCHA)

The high latitude seas of the North Atlantic are currently experiencing major changes (ocean warming, declining ice cover and major increases in heat loss to the atmosphere) associated with man-made climate change. These seas, specifically the Labrador, Irminger and Nordic (LIN) Seas are the key northern sites for the global ocean circulation. In recent research, we developed a temperature dataset spanning 2004-2008 for the Labrador and Irminger Seas from Argo float and Marine Mammal-Borne Sensor (MMBS) data. Our analysis of this dataset revealed that estimates of ocean boundary current temperatures in widely used international datasets are too warm by up to 2 deg Centigrade. Identification of such warm biases is critical to both observation and model-based studies of climate change impacts in this region.

In our earlier study, we were restricted to a small spatial domain and a limited time period ending in 2008. However, as a result of expansion of the Argo float programme, new availability of additional MMBS data and the inclusion for the first time of glider and ship based measurements, we are now in position to develop a new much-enhanced dataset. Specifically, we are now able to extend the spatial domain to include the Nordic Seas (thereby including all North Atlantic dense water formation regions) and the time period to 2003-2012 (allowing a full examination of key changes in the past decade). In addition, it is now possible to include salinity as well as temperature, thereby enabling new insights into changing freshwater content and ocean density.

We propose to develop a world-leading new T and S dataset covering the Labrador, Irminger and Nordic Seas, which will be the first to employ all available observations across this region. Furthermore, we will use the new dataset to a.) determine recent and ongoing changes in the LIN Seas, and b.) critically evaluate the NEMO ocean model (NERCs flagship computer model of the ocean) and thus identify the extent to which it can be relied upon to provide further insights in this area. The proposed research is a major advance on our previous study and is vital as the LIN Seas are widely recognised to be a key indicator region for the early detection of climate change impacts.

The leading-edge datasets and scientific results from ROCHA will have an extremely wide range of impacts in a diverse range of fields including climate research, ocean observations, ocean modelling and marine biology. It will support policy and policymakers in the fields of climate change as well as management of marine mammals and the identification of areas at environmental risk. The new Labrador, Irminger and Nordic Seas (LIN Seas) temperature and salinity dataset will be vital for operational and longer term monitoring and model prediction.

The National Oceanography Centre (NOC), British Antarctic Survey (BAS) and Scottish Oceans Institute Sea Mammal Research Unit (SMRU) all provide impartial, independent and innovative science of high relevance to society. All investigators have experience in engaging with politicians and policy advisors. Dr Josey is a Lead Author of Chap. 3 Ocean Observations of the IPCC 5th Assessment report (IPCC, 2013) and as such is helping to facilitate evidence-based policymaking. By involving our Canadian colleagues we have developed an effective strategy for planning and managing existing infrastructure, thereby enhancing UK research capability in the LIN Seas. The major new outcomes of the project will be recorded in leading scientific papers and disseminated widely through international conferences that will attract a wide and relevant audience.

The NOC, BAS and SMRU have very strong ties with UK Government departments, in particular through the UK Meteorological Office (UKMO) who will be a key beneficiary of the datasets produced in this research. We have long experience of working with the UKMO (with a focussed connection to their Hadley Centre for Climate Prediction and Research) in this way having developed the NOC air-sea flux climatology dataset in collaboration with them in the 1990s. Our recent experience in interdisciplinary work and involvement in climate research will also help to facilitate co-operation between the ocean science and marine mammal communities. Dr Boehme and Dr Meredith have very strong connections through past projects to marine mammal biologists studying populations in the North Atlantic and Southern Oceans. In particular, they have a long history of working with the Department of Fisheries and Oceans, Canada (DFO) and the Norwegian Polar Institute, Norway (NPI).

Dr Josey and Dr Grist will facilitate distribution of the new LIN Seas dataset via the NOC website and thus ensure a wide take up by the scientific community. They have long standing experience of managing datasets in this way, specifically versions 1.1 and 1.1a of the NOC flux climatology, which have over 230 citations between them. An important application of the new LIN Seas dataset will be to evaluate the ocean component (NEMO) of the family of Met Office climate prediction models. Grist, as a participant in the UK Global NEMO Science Working Group, will ensure this takes place. We have past experience of summarizing key results for policy makers through contributions to the United Kingdom Marine Climate Change Impacts Partnership (MCCIP) annual report card. A summary document of major project findings along similar lines will be produced and made available from the project website. We will also produce a short, non-technical summary of each journal article resulting from this work. These summary sheets, and associated publications, will be circulated to Department of Energy and Climate Change personnel to ensure updates to their central electronic data bank. PI Josey and Named Researcher Grist will ensure strong project public outreach (with further key contributions from Boehme and Meredith) by producing the ROCHA web-site, and communicating the science to journalists, educators and students and the public by direct contacts, interviews and public talks.