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Oceanography in 2025: Proceedings of a Workshop
Prospects for Oceanography in 2025
Michael Gregg*
SCIENTIFIC OPPORTUNITIES AND NEEDS
Continental shelves, slopes, and fronts are proving to be far more complex than typical open-ocean mesoscale features that occupied much of our attention in previous decades. Because these domains may not be major influences on climate dynamics, justifying intensive research there can be a “hard sell” to NSF. But, because our Navy is likely to operate in these places, they should remain a focus of ONR for several decades.
At best, process studies near coasts and fronts catch glimpses of important dynamics for a few days or weeks, with hints of much more variability than was captured. Adequate understanding will require observations both more dense and more sustained than anything attempted to date. Fleets of autonomous vehicles, some propelled, some not, offer the only hope. ONR’s Persistent Littoral Undersea Surveillance Network (PLUSNet) program is a prototype of what can be done, but, to obtain scientific results, an academically-based facility is needed, similar to the National Center for Atmospheric Research’s (NCAR) fleet of research aircraft. The task is too much for individual PIs. And the level of coordination needed during measurements is not likely to result from groups of PIs coming together for a few weeks. Combining engineers, technicians and oceanographers, this group should be run by an experienced oceanographer, with oversight by a board of peers chartered by and reporting to ONR.
*
Applied Physics Laboratory, University of Washington
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Oceanography in 2025: Proceedings of a Workshop
INSTRUMENTATION
Driven by ONR, advances in vehicle technology are one of the major successes of the past decade. Lacking so far is a corresponding development of small, robust sensors to take full advantage of these platforms. MEMS (Micro-Electro-Mechanical Systems) technology is advancing rapidly in many other fields (e.g., inkjet printers, accelerometers for deploying airbags in cars and stabilizing images on small cameras, and tiny gyroscopes to trigger dynamics stability controls). Systematic effort is needed to compare capabilities of MEMS and nanotechnologies with needs and opportunities for sensors on autonomous ocean vehicles.
As one example of sensor development, microstructure probes have not improved significantly for thirty years. Thinistors, combining the sensitivity of thermistors with the speed of cold films, are badly needed for use on vehicles moving at one knot or faster. I tried and failed several years ago, and now Ray Schmitt has a grant. If that is not successful, the lessons learned should be used to try again; the task is eminently feasible. Velocity microstructure is sensed using a dwindling supply of bimorph beams made for phonographs. Replacements are badly needed, and they must be far more resistant to water leakage than present probes to work for months on gliders or profiling floats. Finally, because high-frequency vibrations are endemic to vehicles, especially ones with propulsion, tiny but sensitive accelerometers are needed that can be mounted much closer to the probes than at present to remove vibration signatures.
On somewhat larger scales, direct measurements of salinity and density are likely the only way of solving problems posed by “salinity spiking” resulting from mismatches in dynamic responses of temperature and conductivity probes. Smaller probes will also permit mounting more types of sensors on front ends of vehicles. Improvements are beginning, but there is a long way to go to take full advantage of the new vehicles. The effort will require teams of oceanographers and engineers working together for considerably longer than the three- to four-year spans of typical grants.
PEOPLE
Who will do the work? Present trends show declining interest in physical science by American undergraduates. In particular, we are not graduating many students experienced in developing new instruments; success is uncertain, and oceanography faculties want Ph.D. students to demonstrate that they can do science rather than engineering. Worrying in themselves, these trends are particularly ominous for the Navy.
Last year several of us met with RADM Landy, the previous Chief of Naval Research, asking him what we could do to help naval ocean-
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Oceanography in 2025: Proceedings of a Workshop
ography. He responded with a question: “How can 6.1 research, oceanographic in our case, give the U.S. Navy a competitive edge?” My conclusion is that it presently offers much less competitive advantage than previously; our results are published in open journals, immediately available over the Internet, and the large number of foreign students and faculty ensure that advances in the art of understanding the ocean are rapidly transmitted abroad. The only prospect for a competitive edge that I can see lies in our results being picked up more rapidly by our applied Navy labs and contractors than by similar foreign groups. This, in turn, is also under stress. There is a shortage of U.S. citizens with oceanographic Ph.D.s to staff applied groups, such as NRL, and my sense is that the gap between these groups and the academic community has widened during the last decade or more. For example, participation of NRL personnel in joint work at sea is much less than it had been. Several steps can be taken by ONR to address RADM Landy’s question.
ONR can require that a significant fraction of the graduate students it supports be U.S. citizens. Provided that PIs can count on student support, this will require them to recruit undergraduates rather than filling their needs with foreign students.
ONR can facilitate joint work and exchanges of personnel between academia and Navy labs. The Department of Defense (DOD) has recently developed a limited program along these lines, but ONR is in a position to make much more targeted impacts on ocean-related work by establishing joint workshops and field programs. Some elements of these exist, but the scope should be expanded to be effective. One aspect is facilitating academic oceanographers in getting security clearances to understand naval problems in enough depth to contribute to solutions. This, of course, will only work if some academic oceanographers are willing to devote some of their time to helping the Navy in ways not leading to open publications. Owing to the general tightness of funding, linking 6.1 funding to helping Navy labs and programs would be a strong inducement.
