Janzen, C.D. and K.-C. Wong. 2002.
Wind forced dynamics at the estuary-shelf interface of a large coastal
plain estuary. Journal of Geophysical Research, Vol. 107, No. C10, 3138,
doi: 10.1029/2001JC000959.
Summary
Wind-driven circulation and exchange at the estuary-shelf
interface of a large coastal plain estuary is shown to be more complex
than traditional coastal pumping models suggest. Not only is along-estuary
wind forcing important at generating interior bay surface slopes, but it
appears to subsequently force subtidal current fluctutions that may be
equal in magnitude or exceed those due to remote forcing over the shelf,
depending on the seasonal wind forcing and stratification. Furthermore,
it is shown that the orientation of the principal wind stress over a given
period of observations will determine the roles of remote and local effects
on estuarine currents, even at the estuary mouth where the remote coastal
effect is expected to dominate. Findings suggest that local forcing cannot
be ignored in studies of estuary-shelf exchange near shelf boundaries of
large estuaries.
The results of this work have implications to our understanding of larval recruitment and estuary-shelf exchange. Entry of crab larvae into the Delaware Estuary is thought to occur during downwelling favorable (northeasterly) wind events, when the respondent rise in sea level (remote effect) drives a subtidal flow into the bay. However, data suggest that northeasterly wind evetns are only weakly correlated with recruitment patterns in Delaware Bay. Since late-stage crab larvae do not occupy the entire water column at any given time but rather are typically found in the upper 2-3 m along the inner shelf prior to recruitment , they may be more susceptible to depth and laterally dependent circulation. Hence, along-estuary (local) wind effects may be equally if not more important than the alongshelf (remote) wind effects to the recruitment of larvae between the estuary and the shelf.
Please see the published paper for full story and for references.
New and relevant references not available at the time of this paper publication:
Tilburg, Charles. E. 2003. Across-shelf transport on a continental shelf: Do across-shelf winds matter? Journal of Physical Oceanography, (33) (December), pp. 2675-2688.
Valle-Levinson, Arnoldo, Cristobel Reyes, and Rosario Sanay. 2003. Effects of bathymetry, friction, and rotation on estuary-ocean exchange. Journal of Physical Oceanography, (33) (November), pp. 2375-2393.
Wong, K.-C., and A. Valle-Levinson. 2002. On the relative importance
of the remote and local wind effects on the subtidal exchange at the entrance
to the Chesapeake Bay. Journal of Marine Research, (60), pp. 477-498.