A short history of the OSU Buoy Group

The Buoy Group operated at Oregon State University for more than 35 years. It was active in the development and use of deep-sea mooring techniques and instruments, particularly current meters and meteorological instruments. The Buoy Group was a major participant in the World Ocean Circulation Experiment (WOCE) and operated the WOCE Current Meter Data Assembly Center.

In the early 1960s the recently formed OSU Department of Oceanography began to make observations off the Oregon coast. June Patullo, one of the Department's founding members, recognized that mooring work should be a part of the data collection effort. Dale Pillsbury, who later led the Buoy Group, was hired at this time by Wayne Burt. Together with Bob Still and Dennis Barstow, who already were making hydrographic observations, he became involved in the initial mooring effort.

The earliest data in the present archive were obtained with Braincon current meters and thermographs beginning in 1965. The Braincon instruments recorded on photographic film and produced time series one or two months in length, with a sampling interval as short as 5 minutes. Reading the film was difficult and time-consuming. Each frame of a current meter film showed a dot of light whose position encoded a speed and direction. These early experiments were conducted under the supervision of June Patullo and took place in shallow water over the Oregon continental shelf.

The Buoy Group began to deploy Aanderaa current meters in 1972. These instruments were first used in the Coastal Upwelling Experiment (CUE-1). This was the Buoy Group's first large-scale experiment and was conducted jointly with scientists from PMEL and the University of Washington. By this time the Group was being managed by Dr. Robert L. Smith, who was also a PI of CUE-1. CUE-1 was the first of a series of experiments off the US west coast, Peru and West Africa to examine coastal dynamics, particularly upwelling, in relation to biological production.

The Buoy Group's first Aanderaas (the RCM4 and RCM5) employed a mechanical encoder and recorded 10-bit numbers on magnetic tape. Speed was measured with a type of Savonius rotor. In terms of accuracy and ease of use, these current meters represented a major advance over the Braincon instruments. A significant drawback, however, was the mismatch between speed and direction. Speed was recorded as an average over the sampling interval, whereas direction was measured instantaneously at the end of the interval. A second problem was the mechanical encoder, which employed a rotating arrangement of pins and wedges to transform voltages into 10-bit binary numbers. Although the mechanism was ingenious, there was a tendency for the pins to stick, injecting spurious powers of 2 into the result.

The original Aanderaas eventually were upgraded to solid state electronics. This happened in the late 1980's. The modified instruments retained the Savonius-style rotor and large vane of the earlier design, although by this time Aanderaa had introduced a paddlewheel rotor and a smaller vane. These current meters, which were designated RCM7 and RCM8, recorded in CMOS RAM and employed a vector-averaging scheme. They were inherently reliable and corrected most of the failings of the RCM4 and RCM5. The RCM7 and RCM8 remained mainstays of Buoy Group operations until the Group disbanded.

Our initial experience with vector-averaging current meters, however, involved the InterOcean S4. We began experimenting with S4's in the mid-1980's. The S4 was spherical and contained no moving parts. It measured current components by assessing voltages generated as water passed through high-frequency magnetic fields created by a coil at the instrument's equator. S4's were employed in only a few Buoy Group experiments. The instrument was unstable and difficult to calibrate. Because the constant term in its speed calibration tended to drift it was not reliable in low-velocity environments.

Dale Pillsbury, who had been a member of the Buoy Group from its inception, took over management of the Group in 1975 and remained in charge until we disbanded. During his tenure the Group participated in experiments in every ocean and in both shallow and deep-water environments. A computer-controlled tow tank was built, along with automated calibration facilities for temperature and conductivity sensors. The tow tank figured in studies of the response of various current meter rotors and vanes. We learned, for example, that the Savonius-style rotor of the earlier Aanderaas was more sensitive and had a lower stall speed than the paddlewheel of later models. The tow tank work motivated our retention of the Savonius rotor in the RCM7 and RCM8, and provided us with a nonlinear speed calibration that was more accurate than the linear calibration supplied by the manufacturer.

Our success in the early coastal work described above led to requests from others in the oceanographic community for our help in mounting mooring experiments. We learned that a skilled field team could do more work than OSU oceanographers required or could fund. The reasoning is simple: A given field experiment produces a great deal of data and requires a year or two of analysis to understand the results. During this data assimilation phase, the field team is not required by the scientists who designed the experiment. It is efficient to employ the team and the equipment in other experiments planned and carried out by other scientists.

Thus the Buoy Group began a long and fruitful relationship in the mid-1970s with scientists in the Deparment of Oceanography at Texas A & M University. This relationship produced the Drake Passage experiments (FDRAKE 75, 76, 77, and 78; Drake 79), the Falkland Islands Experiment (MAPCOWS), a large array northeast of New Zealand (WOCE component PCM9, also known as MAPKIWI), and an Indian Ocean experiment (WOCE component ICM3). During this period the Buoy Group continued to participate in experiments with oceanographers from OSU and a number of other institutions.

The Buoy Group's success rate in these experiments, and the relatively low cost of its moorings and its data processing operation, led to a recognition at NSF that we presented an opportunity for the establishment of a national facility. At NSF's request we prepared and submitted a proposal for support to do mooring work for the entire oceanographic community. The proposal was well reviewed but was declined because of a policy decision not to support national facilities in general. Subsequently NSF continued to view the Buoy Group as a support facility but chose to allow it to operate as a free agent.

Thus we continued to work with oceanographers at OSU and at a number of other institutions, most notably the University of Washington, Columbia University, the University of Maine, The Monterey Bay Aquarium Research Institute, the Naval Postgraduate School, Scripps Institute of Oceanography, Woods Hole Oceanographic Institute, North Carolina State University, and Texas A & M University.

During the 1990's the Buoy Group provided instruments, installed moorings, and processed data for four components of the World Ocean Circulation Experiment: ACM4, ICM3, PCM9, and PCM11. The Buoy Group also constructed and operated the WOCE Current Meter Data Assembly center (CMDAC). CMDAC's mission was to acquire all the WOCE current meter data, process it to a uniform standard, and make it available online. These data were put online and eventually were published as part of the WOCE CDROM set.

For most of the Buoy Group's run, data processing and software services were provided by Dennis Root and Joseph Bottero. In the beginning, data read from Braincon film was punched onto cards and taken the OSU computer Center's CDC 3300 mainframe. Later, when remote teletype connection to the 3300 became available, we were able to operate the machine from our offices, though it still was necessary to enter the current meter records by card.

With the advent of Aanderaa current meters, which recorded on magnetic tape, we were able to read the data into our own minicomputers. Our first tape reader was built in-house and utilized a reel-to-reel Sony tape deck, which was connected to a PDP-11 computer. The PDP-11 occupied its own air-conditioned room and operated under a 2-user operating system purchased from the Oregon Research Institute. In the late 1980s the PDP-11 was replaced by desktop Sun workstations and PCs. The PCs were utilized for Aanderaa tape-reading and the Sun workstations did the heavier lifting. Eventually, when the Pentium chip arrived, we replaced the Sun workstations with high-end PCs. PC hardware was less expensive and the Microsoft operating system proved to be a more productive software development environment than the UNIX X-11 interface of the Suns.

The Buoy Group's database work began in the late 1980s. Prior to that time the current records had been kept on magnetic tape. When inexpensive disk storage became available the data were moved to disks and we began work on a disk-based system utilizing the Ingres relational database. The Ingres software (which ran on the Sun Workstations) was awkward and slow and eventually was replaced by simpler, faster, home-grown software. At about this time we developed a beautiful X-11 graphical interface to the database that plotted time series, frequency histograms, and energy spectra. Under contract to Texas A & M we also developed a hydrographic database with a similar graphical interface.

Both the current meter database and the hydrographic database were designed for internet access. Unfortunately, internet speeds were insufficient for the X-11 images. Although these interfaces could be used locally they were too slow for remote access. When the Buoy Group acquired fast PCs the current meter database migrated to Microsoft Access. Concurrently an HTML World Wide Web interface was created. This product later became the WOCE current meter database. Although the WWW interface lacked the features and visual quality of the earlier X-11 interface, it probably was the best that could be done over the internet at that time. Eventually the Buoy Group's Web operations were moved away from Microsoft software to Linux and a MySQL database.

Over the years, many people contributed to the success of the Buoy Group. Some of the names are Dennis Barstow, Mindy Berger, Lily Bogert, Joseph Bottero, Curt Collins, Clayton Creech, Bill Gilbert, Chris Mooers, Ben Moore, June Patullo, Dale Pillsbury, Dennis Root, Rich Schramm, Ed Siefert, Jay Simpkins, Bob Smith, Bob Still, ...

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