ACM11 (Romanche/Chain Fracture Zone component of Deep Basin)

This component of the Deep Basin experiment produced 39 current meter records from 7 moorings. You can view metadata and/or download the records by clicking on links in the table below. A brief description of the experiment also is available. Each current meter record is identified in the table by its depth and the name of the mooring. You may want to look at a map of the array first to see where the moorings were. If you download any of the current meter records you should review the note on file format. From here you can also move up one level to the list of WOCE experiments.

mooringinstr depthinstr typedatesmetadatadownload
R1 1700 meters Aanderaa RCM5 17 Nov 92 - 31 Oct 94 view metadata download record
R1 2000 meters Aanderaa RCM8 17 Nov 92 - 31 Oct 94 view metadata download record
R1 2800 meters Aanderaa RCM5 17 Nov 92 - 31 Oct 94 view metadata download record
R1 3750 meters Aanderaa RCM8 17 Nov 92 - 31 Oct 94 view metadata download record
R1 3950 meters Aanderaa RCM5 17 Nov 92 - 31 Oct 94 view metadata download record
R1 4100 meters Aanderaa RCM8 17 Nov 92 - 31 Oct 94 view metadata download record
R3 3950 meters Aanderaa RCM5 18 Nov 92 - 31 Oct 94 view metadata download record
R3 4100 meters Aanderaa RCM8 18 Nov 92 - 31 Oct 94 view metadata download record
R3 4200 meters Aanderaa RCM5 09 May 93 - 31 Oct 94 view metadata download record
R3 4315 meters Aanderaa RCM8 18 Nov 92 - 31 Oct 94 view metadata download record
R4 1700 meters Aanderaa RCM5 18 Nov 92 - 01 Nov 94 view metadata download record
R4 2000 meters Aanderaa RCM8 18 Nov 92 - 01 Nov 94 view metadata download record
R4 3200 meters Aanderaa RCM8 18 Nov 92 - 01 Nov 94 view metadata download record
R4 3750 meters Aanderaa RCM5 18 Nov 92 - 01 Nov 94 view metadata download record
R4 3950 meters Aanderaa RCM8 18 Nov 92 - 01 Nov 94 view metadata download record
R4 4100 meters Aanderaa RCM5 18 Nov 92 - 01 Nov 94 view metadata download record
R4 4265 meters Aanderaa RCM8 18 Nov 92 - 01 Nov 94 view metadata download record
C1 1700 meters Aanderaa RCM5 19 Nov 92 - 02 Nov 94 view metadata download record
C1 2000 meters Aanderaa RCM8 19 Nov 92 - 02 Nov 94 view metadata download record
C1 2800 meters Aanderaa RCM5 19 Nov 92 - 02 Nov 94 view metadata download record
C1 3750 meters Aanderaa RCM8 19 Nov 92 - 02 Nov 94 view metadata download record
C1 3950 meters Aanderaa RCM5 19 Nov 92 - 02 Nov 94 view metadata download record
C1 4100 meters Aanderaa RCM8 19 Nov 92 - 02 Nov 94 view metadata download record
C1 4165 meters Aanderaa RCM5 19 Nov 92 - 26 Jul 94 view metadata download record
C2 3950 meters Aanderaa RCM8 19 Nov 92 - 02 Nov 94 view metadata download record
C2 4100 meters Aanderaa RCM5 19 Nov 92 - 02 Nov 94 view metadata download record
C2 4230 meters Aanderaa RCM8 19 Nov 92 - 02 Nov 94 view metadata download record
C2 4365 meters Aanderaa RCM5 19 Nov 92 - 02 Nov 94 view metadata download record
C2 4550 meters Aanderaa RCM8 19 Nov 92 - 02 Nov 94 view metadata download record
C3 3950 meters Aanderaa RCM8 20 Nov 92 - 03 Nov 94 view metadata download record
C3 4100 meters Aanderaa RCM5 20 Nov 92 - 03 Nov 94 view metadata download record
C3 4230 meters Aanderaa RCM8 20 Nov 92 - 03 Nov 94 view metadata download record
C3 4365 meters Aanderaa RCM5 20 Nov 92 - 03 Nov 94 view metadata download record
C4 1700 meters Aanderaa RCM5 20 Nov 92 - 03 Nov 94 view metadata download record
C4 2000 meters Aanderaa RCM8 20 Nov 92 - 03 Nov 94 view metadata download record
C4 3200 meters Aanderaa RCM5 20 Nov 92 - 03 Nov 94 view metadata download record
C4 3750 meters Aanderaa RCM8 20 Nov 92 - 03 Nov 94 view metadata download record
C4 3950 meters Aanderaa RCM5 20 Nov 92 - 03 Nov 94 view metadata download record
C4 4100 meters Aanderaa RCM8 20 Nov 92 - 03 Nov 94 view metadata download record

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Brief description of ACM11

The goal of these current measurements, which were undertaken in the Romanche and Chain Fracture Zones, was to obtain an estimate of the bottom water transport from the western to the eastern basins of the equatorial Atlantic Ocean. In this case, bottom water is defined as water with a potential temperature less than 1.9 deg C. The mooring arrays sampled the two pathways for bottom water across the Mid-Atlantic Ridge (Mercier et al. 1994). Results are presented in Mercier and Speer (1998) and will be used in the construction of a mass budget for the bottom water in the Brazil Basin.

In all, there were eight moorings (see map), four in the Romanche Fracture Zone (Moorings R1, R2, R3, and R4) and four in the Chain Fracture Zone (Moorings C1, C2, C3, and C4). All moorings except R2 were recovered successfully.

The moorings were instrumented with a mixture of Aanderaa RCM5s and RCM8s. The RCM5s measured speed, direction, and temperature every two hours. The RCM8s measured speed, direction, temperature, and pressure hourly. Every current meter recorded two temperature series (from the same thermistor): one series with a resolution of 0.024 deg C over the range -2 to 21 deg C, and the other with a resolution of 0.008 deg C over a much narrower range. We have included in the database only one temperature series from each instrument; wherever possible we selected the series with the higher resolution.

The dataset is described in detail in the Internal Report LPO 97-01, titled "Campagne Romanche 3", of IFREMER's Laboratoire de Physique des Oceans. Some related publications:

Mercier, H., K. Speer, and J. Honnorez (1994): Flow pathways of bottom water through the Romanche and Chain Fracture Zones. Deep-Sea Research, 41(10), 1457-1477.

Speer, K., H. Mercier, M-J. Messias and L. Memery (1994): The Romanche Fracture Zone:blocking and mixing of Arctic and Antarctic waters at the equator. International WOCE Newsletter, 16, 8-11.

Mercier, H. and H. Bryden (1994): Flow of Antarctic Bottom Water over the sill in the Romanche Fracture Zone. International WOCE Newsletter, 17, 9-10.

Bryden, H. and H. Mercier (1995): Control of the deep circulation in the Brazil Basin by the sill in the Romanche Fracture Zone. International WOCE Newsletter, 21, 27-30.

Mercier, H. and P. Morin (1997): Hydrography of the Romanche and Chain Fracture Zones. J. Geophys. Res, 102(C5), 10373-10389.

Mercier, H. and K. Speer (1998): Transport of bottom water in the Romanche Fracture Zone and Chain Fracture Zone. Journal of Physical Oceanography, 28(5), 779-790.

Ferron, B., H. Mercier, K. Speer, A. Gargett and K. Polzin (1998): Mixing in the Romanche Fracture Zone. Journal of Physical Oceanography, 28(10), 1929-1945

Ferron, B., H. Mercier and A. Treguier (2000): Modeling of the bottom water flow through the Romanche Fracture Zone with a primitive equation model - Part 1: dynamics. J. Marine Res., 58(6), 837-862.

Lux, M., H. Mercier and M. Arhan (2001): Interhemispheric exchanges of mass and heat in the Atlantic Ocean in January-March 1993. Deep-Sea Research I, 48(3), 605-638.

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Format of the current 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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