How did we get to this point: embarking on a huge field programme?

All good science programmes begin with an excellent idea. Without ideas, and the ability to explain them to specialists and non-specialists, no scientist would ever get new funding. So an important part of our job is to think creatively about what the next big question is, and how we might design an experiment to investigate it. The best projects come from scientists talking together, pinning down the details of what we do know, what we don’t know, and how we might find out more using the resources we have, or might have if we designed new technology.

For OSNAP, the idea has been several years in the making, and was at least in part inspired by the outstanding results that have come from the UK-US project in the subtropical North Atlantic, called RAPID ( and For 10 years the RAPID project has been continuously measuring the heat carried northwards by the ocean; a hugely significant part of our climate system. It does this through the use of instruments strung along a series of vertical ropes tethered on the seafloor by a huge pile of anchor chain, and held near the surface with air-filled glass balloons. The instruments record the speed and direction of the water flow, as well as temperature and salinity. With some clever but relatively straightforward maths, the scientists can turn those measurements into a record of the volume of warm salty water flowing northward in the top kilometre of the ocean, the volume heading south in the deep ocean, and the volume going round and round the subtropical gyre. This matters because the heat flowing north warms the higher latitudes – a simple decrease in that flow, perhaps a response to changing winds, can cool the northern North Atlantic considerably.

But it is clear that while the subpolar North Atlantic (that is the region between Canada, Greenland, Iceland and NW Europe) has a similar northward flow of warm water, and southward flow of cold deep water, there is a lot more going on too. The conditions in the subpolar area are not simply a reflection of whats happening in the subtropics; they probably also respond to changes in the Arctic, and local changes in circulation (another response to changing winds). And this matters to people not just in a climate sense (which can feel rather abstract to many), but because ocean-atmosphere feedback means that our weather patterns change with the ocean conditions. The weather (and climate) system is riddled with feedback mechanisms, and amazingly the conditions in the subpolar North Atlantic can affect a range of unexpected things, including the number of blocking highs over Europe, rainfall in the US, or even rainfall in the Sahel.

So in 2010 scientists from UK, US, Canada, France, Germany and the Netherlands met in order to talk about how to make RAPID-style measurements in the subpolar region. We defined the scientific questions and designed the experiment to address them. Each scientist went back to their own country (after a small delay caused by grounded flights due to volcanic ash…) to write a proposal to their own funding agency. In the following months the proposals were coordinated and reviewed within the group, to make sure they were clearly explained, and that the plans for fieldwork and model analysis were effective and made the best use of resources. Our funding agencies encourage international programmes like this because they are so cost-efficient and beneficial. There is no way that NERC could afford a programme like this alone, but as part of an international effort we can achieve hugely significant results.

That’s not to say it is easy to get the money though! All proposals go through peer-review – the process of sending them out to other scientists who scrutinise the scientific arguments and the plans for research and critically review them. The UK and US OSNAP proposals were not funded first time – the reviewers were not quite persuaded of the value of the proposals as we had set them out. Receiving reviews can be painful, but they can also be constructive and used to improve the science. We took notice of the feedback and resubmitted the proposals in 2012. In 2013, after a new round of peer review that was extremely positive, NERC and NSF agreed to fund the UK and US programmes and we immediately set about planning the fieldwork.

The co-ordination of the OSNAP programme continues of course. The group of lead investigators will meet in person every couple of years, but there are conference calls and email exchanges to make sure we are making the best decisions for the programme. We share ideas, shiptime, data and results. Each of us will be pursuing our own particular strand of research, but together we will weave a new understanding of how the subpolar North Atlantic works, which will feed into global knowledge of our climate system.

The cruise we are about the set out on is the first part of the OSNAP fieldwork and it is very exciting to finally put into practice the work we have been planning for so long. I cant wait!