Mr. Tom's Blog

The extraordinary potential of merchant marine vessels for ocean science.

One thing that really baffles me is the lack of interest in the oceanographic community for teaming up with the merchant marine (MM) for ocean observation. You would think it would be exactly the other way around, for who has a presence on the high seas if not the shipping industry. Most everywhere and all the time, now and forever. There are, of course, some important exceptions, the volunteer observing programs (VOS) provide weather and sea surface reports, and the Ship of Opportunity programs (SOOP) include XBTs, surface water properties, and surface plankton distributions. In addition, a very few ships are equipped with acoustic Doppler current profilers (ADCP) to scan upper ocean currents. But we could be doing so much more!

I am very partial to the ADCP for it scans the ocean in two dimensions, kind of like taking repeat X-rays of the upper ocean. Profiling the vertical structure of currents is what the ADCP does, operating it on a moving vessel resolves the horizontal structure of the velocity field. This is a big deal for the alternative, to use hydrography together with the dynamic method is all but impossible. The reason is that the scale of variability in the ocean is set by the radius of deformation, which is measured in O(10) kilometers. These scales are too small to be resolved using hydrography, but an ADCP-equipped ship in regular traffic can scan the velocity field repeatedly and accurately with O(1) kilometer resolution, not only at the surface but to 300-1000 m depths depending upon type of ADCP.

Starting in fall 1992 the container vessel Oleander, operating between Bermuda and New Jersey, has been scanning upper ocean currents. Besides crossing the Gulf Stream twice weekly, she also traverses the waters to either side: the Slope and Sargasso Seas. We began to build up a highly resolved picture of these currents from which we could construct transports and how these vary on seasonal and longer time scales. Later, Charlie Flagg and I instrumented two other vessels, the Nuka Arctica crossing the subpolar north Atlantic at ~60°N and the Norröna spanning the warm water flow into the Nordic Seas between Iceland and Scotland. While we had serious problems with bubbles interfering with the Norröna ADCP, the basic message from all these ships was clear: a single instrument on a vessel in regular service is an incredibly cost-effective approach to resolving the space-time variability of the oceanic velocity field.

To develop interest in merchant marine-based ocean observation, we obtained funding from SCOR and IAPSO to organize a set of international workshop meetings to develop a concept called OceanScope. Prof. Kuh Kim of Korea and I were co-chairs and Prof. Peter Ortner executive secretary. It included experts in science, sensor technology, marine architecture, marine law, and included representation from the shipping industry. I’m very proud of the final report we put out (see link below). Especially its focus on how we might team up with the MM. While the report begins with a scientific motivation, it has a heavy emphasis on how we might implement an ocean observing program with the MM. The report recognizes and encourages initiatives to develop novel sensors and technologies optimized for that environment. Indeed, a major point of the report was to create a framework, culture or better yet, let’s say, an enthusiasm for working with the MM, Unfortunately, without realizing it at the time, I made a serious mistake. We should have used the report as the basis for a proposal to fund an initial effort.

When I presented the report to the federal agencies, I was naively thinking they would like the idea so much they would put out a call for proposals to carry the idea forward. The benefit to NASA would be an organized and sustained approach to providing ground truth of surface water properties (including salinity), surface currents and ocean color (upwelled light and lidar). I envisioned NSF would be excited about new initiatives in both science and sensor technology, and I thought NOAA would welcome especially the ADCP methodology as a strong supplement to their ongoing XBT program. Sadly, I was wrong, the OceanScope report went nowhere fast.

The funny thing is that the shipping industry is more onboard with these ideas of collaboration than the scientific community. In virtually all cases where we have approached a company about instrumenting a vessel the response has been positive if not enthusiastic, they want to be helpful. Really, the only constraint they impose on us is that we do not disturb their activities. And that isn’t an issue since any and all instruments onboard are fully automated. Really, it is up to us to take the initiative.

https://scor-int.org/Publications/OceanScope_Final_report.pdf