Inner-shelf response to cross-chelf wind stress : the importance of the cross-shelf density gradient in an idealized numerical model and field observations
MetadataShow full item record
This study investigates the effects of horizontal and vertical density gradients on the inner-shelf response to cross-shelf wind stress by using an idealized numerical model and observations from a moored array deployed south of Martha’s Vineyard, Massachusetts. In two-dimensional (no along-shelf variation) numerical model runs of an initially stratified shelf, a cross-shelf wind stress drives vertical mixing that results in a nearly well-mixed inner shelf with a cross-shelf density gradient because of the sloping bottom. The cross-shelf density gradient causes an asymmetric response to on- and offshore wind stresses. For density increasing offshore, an offshore wind stress drives a near-surface offshore flow and near-bottom onshore flow that slightly enhances the vertical stratification and the cross-shelf circulation. An onshore wind stress drives the reverse cross-shelf circulation reducing the vertical stratification and the cross-shelf circulation. A horizontal Richardson number is shown to be the nondimensional parameter that controls the dependence of the wind-driven nondimensional cross-shelf transport on the cross-shelf density gradient. Field observations show the same empirical relationship between the horizontal Richardson number and transport fraction as the model predicts. These results show that it is the cross-shelf rather than vertical density gradient that is critical to predicting the inner-shelf cross-shelf transport driven by a cross-shelf wind stress.
Author Posting. © American Meteorological Society, 2014. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 44 (2014): 86–103, doi:10.1175/JPO-D-13-075.1.
Suggested CitationArticle: Horwitz, Rachel M., Lentz, Steven J., "Inner-shelf response to cross-chelf wind stress : the importance of the cross-shelf density gradient in an idealized numerical model and field observations", Journal of Physical Oceanography 44 (2014): 86–103, DOI:10.1175/JPO-D-13-075.1, https://hdl.handle.net/1912/6704
Showing items related by title, author, creator and subject.
Cross-shelf circulation and momentum and heat balances over the inner continental shelf near Martha's Vineyard, Massachusetts Fewings, Melanie R. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2007-09)The water circulation and evolution of water temperature over the inner continental shelf are investigated using observations of water velocity, temperature, density, and bottom pressure; surface gravity waves; wind ...
The effect of stratification on wind-driven, cross-shelf circulation and transport on the inner continental shelf Horwitz, Rachel M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2012-06)Observations from a three-year field program on the inner shelf south of Martha's Vineyard, MA and a numerical model are used to describe the effect of stratification on inner shelf circulation, transport, and sediment ...
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 ...