Subduction - WOCE component ACM25/26

The Subduction experiment produced 232 current meter and temperature records from 5 moorings (each mooring site was occupied three times). You can view metadata and download the time series by clicking on links below. A brief description of the experiment also is available here. You may want to look at a map of the array to see where the moorings were. If you download any of the records you should review the note on file format. From here you can also move up one level to the list of WOCE experiments.

This is an extremely large dataset, and we have put each mooring on a separate page. Click on mooring name below to reach metadata and/or download current records.

Most of the Subduction time series in this database have a time increment of 15 minutes, though some have a 30-minute or 60-minute increment. Some of the 15-minute current meter records were obtained by VMCMs with a 7.5-minute sampling interval. CMDAC does not know whether the 15-minute values were obtained by averaging consecutive 7.5-minute samples, or whether a more sophisticated filter was used.


Brief description of ACM25/26

ACM25/26 focused on subduction, a process in which water formed in the mixed layer of the upper ocean moves downward into the thermocline. The clockwise atmospheric circulation around the Bermuda/Azores High makes the subtropical North Atlantic a preferred region for Ekman layer convergence and subduction. During the field phase of ACM25/26, current meters, temperature recorders, and meteorlogical buoys were deployed in this region beginning in June 1991.

The current meter array consisted of five moorings (see map) each of which was occupied three times. Each of the three deployments was in place for about 8 months, resulting in a total onsite time of two years. The moorings were instrumented with Vector Measuring Current Meters, Brancker Temperature Recorders, and (at the northwest mooring) an Acoustic Doppler Current Profiler. We have included time series from all three types of instrument in this database. Most of the time series have a sampling interval of 15 minutes.

Each mooring also contained, at the sea surface, a meteorological buoy. The meteorological data have not been included here.

The first phase of the field experiment ran from June 1991 through February 1992; the second phase from February 1992 through October 1992; and the third phase from October 1992 through June 1993. At the end of each of the first two phases the moorings were replaced. Unfortunately, in several cases the moorings did not survive the full 8-month period. In many cases, however, one can piece together the 8-month segments to form longer continuous time series.

Publications

Moyer, K.A. and R.A. Weller (1997): Observations of surface forcing from the Subduction Experiment: A comparison with global model products and climatological data sets. J. Climate, 10, 2725-2742.

Furey, P.W., R.A. Weller and M. A. Spall (2000): Simulations of mixed layer response to local atmospheric forcing and inferring the subduction rate in the Northeast Atlantic. To be submitted to: J. Geophys. Res.

Spall, M.A., R.A. Weller and P.W. Furey (2000): Modelling the three-dimensional upper ocean heat budget and subduction rates during the Subduction Experiment. J. Geophys. Res., 105(C11), 26151-26166.

Weller, R.A., K.A. Moyer, P.W. Furey, M.A. Spall and R.A. Goldsmith (2000): The large-scale context for oceanic subduction in the Northeast Atlantic. To be submitted to: J. Geophys. Res.

Cruise Reports

Trask, R.P. and N.J. Brink (1993): Cruise Report R/V Oceanus Subduction 1 Mooring Deployment Cruise. Woods Hole Oceanographic Institution Tech. Rep. WHOI-93-12, 77pp.

Trask, R.P., N.J. Brink, L. Regier and N. McPhee (1993): Cruise Report R/V Oceanus Subduction 2 Mooring Deployment and Recovery Cruise. Woods Hole Oceanographic Institution Tech. Rep. WHOI-93-13, 102 pp.

Trask, R.P., W. Jenkings, J. Sherman, N. McPhee, W. Ostrom and R. Payne (1993): Cruise Report RRS Charles Darwin Subduction 3 Mooring Deployment and Recovery Cruise. Woods Hole Oceanographic Institution Tech. Rep. WHOI-93-18, 98 pp.

Trask, R.P., N. Galbraith, P. Robbins, W. Ostrom, L. Regier, G. Pezzoli and N. McPhee (1993): Cruise Report R/V Knorr Subduction 3 Mooring Recovery Cruise. Woods Hole Oceanographic Institution Tech. Rep. WHOI-93-54, 79 pp.

Data Report

Brink, N.J., K.A.Moyer. R.P.Trask, and R.A.Weller (1995). The Subduction Experiment: Mooring Field Program and Data Summary. Woods Hole Oceanographic Institution Tech. Rep. WHOI-95-08, 113 pp.

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Format of the current and temperature records

These files have been compressed with the ZIP compression utility. After downloading them, you will need to expand them. On a PC, WinZip or Pkunzip will do the job. Other utilities are available for the Unix and Macintosh environments. After expansion, you will have ascii files in OSU's stranger format.

The stranger format begins with several lines of header information that are meant to be machine-readable. They contain a Fortran format specification that will be useful in reading the file, a pointer to the first line of data, and a description of the data. Each line of the current record itself contains the time of the sample, the values recorded, and a line count.

Please be aware that end-of-line in these files is a carriage-return plus line-feed (the PC convention). This means that in a Unix environment (where a single line-feed serves as end-of-line) you may want to remove the carriage-returns.

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