Observations of tidal variability on the New England shelf
MetadataShow full item record
Observations from the Coastal Mixing and Optics experiment moored array, deployed from August 1996 through June 1997, are used to describe barotropic and baroclinic tidal variability over the New England shelf. The dominant M 2 tidal elevations decrease toward the northeast to a minimum over the Nantucket shoals (about 34 cm), and barotropic tidal current amplitudes increase strongly toward the northeast to a maximum over the shoals (about 35 cm s−1). Estimates of the depth-averaged M 2 momentum balance indicate that tidal dynamics are linear, and along-shelf pressure gradients are as large as cross-shelf pressure gradients. In addition, tidal current ellipses are weakly polarized, confirming that the dynamics are more complex than simple plane waves. The vertical structure of the M 2 currents decreases in amplitude and phase (phase lead near bottom) over the bottom 20 m. The M 2 momentum deficit near the bottom approximately matches direct covariance estimates of stress, confirming the effects of stress on current structure in the tidally driven bottom boundary layer. Baroclinic current variability at tidal frequencies is small (2 cm s−1 amplitude), with a predominantly mode 1 vertical structure. High-frequency (approaching the buoyancy frequency) internal solitons are observed following the pycnocline. The internal solitons switch from waves of depression to waves of elevation when the depth of maximum stratification is deeper than half the water column depth. Both low-mode baroclinic tidal and high-frequency internal wave energy decrease linearly with bottom depth across the shelf.
Author Posting. © American Geophysical Union, 2004. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 109 (2004): C06010, doi:10.1029/2003JC001972.
Suggested CitationArticle: Shearman, R. Kipp, Lentz, Steven J., "Observations of tidal variability on the New England shelf", Journal of Geophysical Research 109 (2004): C06010, DOI:10.1029/2003JC001972, https://hdl.handle.net/1912/3710
Showing items related by title, author, creator and subject.
Fewings, Melanie R.; Lentz, Steven J.; Fredericks, Janet J. (American Meteorological Society, 2008-11)Six-yr-long time series of winds, waves, and water velocity from a cabled coastal observatory in 12 m of water reveal the separate dependence of the cross-shelf velocity profile on cross-shelf and along-shelf winds, waves, ...
Dever, Edward P. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1995-06)Moored time series from the Coastal Ocean Dynamics Experiment (CODE), Shelf Mixed Layer Experiment (SMILE), Sediment Transport Events over the Shelf and Slope (STRESS) study, and Northern California Coastal Circulation ...
Flagg, Charles Noel (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1977-04)A 37 day long field program was carried out in March 1974 on the New England continental shelf break to study the current and hydrographic structure and variability on the shelf and in the shelf/slope front. A second ...