Current variability on a narrow shelf with large ambient vorticity

H. Peters, Lynn K Shay, Arthur J Mariano, T. M. Cook

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Surface and subsurface currents and stratification were observed on and near the narrow shelf off Fort Lauderdale, Florida, in June-August 1999. The Florida Current flowed past, occasionally on the shelf, with speeds at times exceeding 2 m s-1 only 8 km offshore. The typical vorticity associated with the lateral shear of the Florida Current was 4f, where f is the local Coriolis parameter. Two dominant modes of higher frequency current variability were embeded in this low-frequency flow, a 10-hour signal with amplitudes of up to 0.5 m s-1 and an equally as strong, almost rectilinear signal with a 27-hour period, the same as the local inertial period. Both signals were propagating northward along the shore with wavelengths of ∼27 and ∼170 km for the 10- and 27-hour signals, respectively, and with corresponding phase speeds of 0.85 and 1.7 m s-1. The phase trend in east-west direction of the 10-hour signal is consistent with unstable, growing waves. The 10- and 27-hour signals appear dominantly barotropic near the coast out to depths of at least 50 m, but the 10-hour signal displayed a 180° phase change between surface and bottom farther away from the shelf break at 160 m depth. The two dominant signals cannot be attributed to barotropic instability.

Original languageEnglish (US)
Pages (from-to)2-1
Number of pages2
JournalJournal of Geophysical Research C: Oceans
Volume107
Issue number8
StatePublished - Aug 15 2002

Fingerprint

Vorticity
shelves
vorticity
Coastal zones
Wavelength
barotropic instability
shelf break
stratification
coasts
shear
low frequencies
wavelength
trends
Direction compound
coast
wavelengths

Keywords

  • Florida Current
  • Flow instability
  • Shelf circulation
  • Surface Doppler radar
  • Vorticity

ASJC Scopus subject areas

  • Earth and Planetary Sciences (miscellaneous)
  • Atmospheric Science
  • Geochemistry and Petrology
  • Geophysics
  • Oceanography
  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Current variability on a narrow shelf with large ambient vorticity. / Peters, H.; Shay, Lynn K; Mariano, Arthur J; Cook, T. M.

In: Journal of Geophysical Research C: Oceans, Vol. 107, No. 8, 15.08.2002, p. 2-1.

Research output: Contribution to journalArticle

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AU - Mariano, Arthur J

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