Transport variability of the Deep Western Boundary Current and the Antilles Current off Abaco Island, Bahamas

Christopher S. Meinen, Silvia L. Garzoli, William E Johns, Molly O. Baringer

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

Hydrography is combined with 1-year-long Inverted Echo Sounder (IES) travel-time records and bottom pressure observations to estimate the Deep Western Boundary Current (DWBC) transport east of Abaco Island, the Bahamas (near 26.5°N); comparison of the results to a more traditional line of current meter moorings demonstrates that the IESs and pressure gauges, combined with hydrography, can accurately monitor the DWBC transport to within the accuracy of the current meter array estimate at this location. Between 800 and 4800 dbar, bounded by two IES moorings 82 km apart, the enclosed portion of the DWBC is shown to have a mean southward transport of about 25 Sv (1Sv=106m3s-1) and a standard deviation of 23 Sv. The DWBC transport is primarily barotropic (where barotropic is defined as the near-bottom velocity rather than the vertical average velocity); geostrophic transports relative to an assumed level of no motion do not accurately reflect the actual absolute transport variability (correlation coefficient is 0.30). The IES-pressure gauge absolute transport within 1200-4800 dbar agrees well with the current meter absolute transports (upper integration limit based on shallowest current meter level); the standard deviation of the difference is 12 Sv and the mean difference is 0.2 Sv. The correlation coefficient between these two time series is 0.76. The northward flowing Antilles Current (AC) east of Abaco Island has a mean baroclinic transport of 6 Sv as estimated by the IESs and a standard deviation of 3 Sv. The AC variations observed during 1996-1997 are uncorrelated with the Florida Current transport variations west of Abaco Island in the Florida Straits, however, the AC transport variations bear some resemblance to the historical estimates of the AC annual cycle.

Original languageEnglish (US)
Pages (from-to)1397-1415
Number of pages19
JournalDeep-Sea Research Part I: Oceanographic Research Papers
Volume51
Issue number11
DOIs
StatePublished - Nov 2004

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western boundary current
Bahamas
meters (equipment)
pressure gauges
echo sounder
hydrology
hydrography
gauge
bottom pressure
travel
time series analysis
annual cycle
travel time
strait
monitoring
time series

ASJC Scopus subject areas

  • Aquatic Science
  • Geology
  • Oceanography

Cite this

Transport variability of the Deep Western Boundary Current and the Antilles Current off Abaco Island, Bahamas. / Meinen, Christopher S.; Garzoli, Silvia L.; Johns, William E; Baringer, Molly O.

In: Deep-Sea Research Part I: Oceanographic Research Papers, Vol. 51, No. 11, 11.2004, p. 1397-1415.

Research output: Contribution to journalArticle

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