Journal of Geophysical Research: Oceans
C09004 (9 pages)
Observations of current velocity profiles were combined with an analytical solution to study the transverse partition of the wind-driven flow in an estuary, the Nansemond River, which is a tributary of the James River in the Chesapeake Bay. Observations spanned two periods of nearly 3 months in autumn-winter of 2003-2004 and spring-summer 2004. The wind-driven circulation consisted of downwind flow over the shoal and upwind flow in the channel at the entrance to the estuary. This pattern developed mainly with landward winds and provided observational evidence that sustains analytical and numerical model results. The transverse structure of the flow showed synoptic temporal variability (3-7 days), which corresponded to the variability of winds and sea level. Synoptic variability seemed to be more influential in autumn-winter than in spring-summer. However, variability of 1-2 days was persistent in both periods of observation. Also, the transverse structure of the wind-driven flows was linked to a counterclockwise recirculation pattern previously observed with survey data. Part of the flow going into the tributary over the shoal might recirculate and form or enhance the outflow in the channel. As suggested by the temporal scale of the wind, the recirculation might weaken or even reverse direction every 3-7 days at the entrance to the estuary. Further detailed studies are needed to better define the extent of this recirculation.
Original Publication Citation
Narvaez, D. A., & Valle-Levinson, A. (2008). Transverse structure of wind-driven flow at the entrance to an estuary: Nansemond River. Journal of Geophysical Research: Oceans, 113(C9), C09004. doi:10.1029/2008jc004770
Narváez, Diego A. and Valle-Levinson, Arnoldo, "Transverse Structure of Wind-Driven Flow at the Entrance to an Estuary: Nansemond River" (2008). CCPO Publications. 237.