by Susan Lozier
Late last month I attended a symposium in London celebrating the tenth anniversary of the UK-US RAPID array at 26°N in the subtropical North Atlantic. All assembled agreed that this first continuous measure of the ocean’s meridional overturning circulation has produced a dramatic shift in our understanding of the large scale ocean circulation in the North Atlantic. Those of us working on the OSNAP project understand all too well that with this dramatic shift RAPID has set a high bar for success. So, to all RAPID PIs, let me offer a congratulatory note on behalf of all OSNAP PIs on this milestone. Well done.
For those of us involved in these large scale ocean observing programs, we have little to no doubt as to their benefit to our science in the short run, and to society in the longer run. But these observations come at a price that is sizable to most any funding agency. This price tag, coupled with the dawning realization that we will need to measure for years and years in order to discern long term trends of the overturning and its attendant heat, carbon and freshwater fluxes, should give us pause. This message more or less was delivered to those assembled in London in the closing remarks given by Professor Duncan Wingham, Chief Executive of the UK National Environmental Research Council (NERC). Professor Wingham noted the irony of an Environmental Research Council funding ships to crisscross the ocean all the while burning (lots of) fossil fuels. It is though the cost of business and oceanographers can hardly be held responsible for the rising cost of fuel over this past decade. And yet, all of us understand that with anything the price must be commensurate with the value added. While we as oceanographers are convinced of the value, I think it is safe to say that outside of our community it may not be so patently obvious.
Thus, we need to continue our efforts to explain our work and, importantly, link it to societal concerns. Basically, there is work to do outside of our community so that the larger public can understand the value added. But there is also work to do inside our community. Professor Wingham’s message is a reminder of what I believe is an obligation on our part to push ahead with new technology to measure the ocean in cost-effective ways. Essentially we need to bring down that price tag, and also bring down our reliance on fossil fuels. I do not pretend to know how we can get there and especially not how we can get there quickly, but I do think that the future of ocean observations will be brighter if we can measure using fewer dollars and fewer resources.
OSNAP was designed with mostly conventional ocean instrumentation, largely because when we were proposing OSNAP our confidence in the conventional far exceeded our confidence in the unconventional. It was pretty much that simple. As a result, for the deployment this summer, it required no less than six cruises to get the sound source and mooring arrays in place. However, we understand that we need to move in the direction of more cost-effective measurements with a lighter footprint. To get there, OSNAP will contribute to an assessment of the critical measurements needed for a multi-decadal observing system and will provide essential ground truth to AMOC model estimates. The intent is to move toward an observing system where a few critical in situ observations with new technology, coupled with satellite observations and the Argo float array, provide a reliable and sustainable measure of the AMOC for decades to come. To get there sooner rather than later we need to push for leaner and cleaner ocean obs.