HR: 1400h
AN: OS23B-03    [Abstracts]
TI: Fortnightly Variability At The Transition Between Two Sub-Estuaries
AU: * Riveron-Enzastiga, M L
EM: lriveron@yahoo.com
AF: Instituto de Ciencias del Mar y Limnologia (UNAM), Circuito exterior s/n Cd. Universitaria, Mexico City, DF 04510, Mexico
AU: Valle-Levinson, A
EM: arnoldo@ufl.edu
AF: Department of Civil and Coastal Engeneering, 558 Weil Hall PO Box 116580, Gainesville, FL 32611, United States
AB: Profiles of current velocity from an Acoustic Doppler Current Profiler (ADCP) and of water salinity, temperature and density from a Conductivity-Temperature-Depth (CTD) recorder, were combined with surface salinity, temperature and density from a Conductivity-Temperature (CT) recorder to elucidate the fortnightly variability at the Lafayette River entrance. The Lafayette River connects at its mouth with the Elizabeth River, which is a tributary to the James River in the Chesapeake Bay. Data were collected in four experiments during consecutive spring and neap tides in the autumn of 2000, and in the spring of 2001. Each experiment was carried out for ~25 hours and consisted of three across-estuary transects: one at the mouth, where the Elizabeth River estuary influences the Lafayette River estuary, and two more toward the head of the estuary. The maximum depth of the transects was <5 m, and despite the shallowness, the mean flow showed two-layer exchange during neap tides. During spring tides there was an evident recirculation where the two sub-estuaries interact and a marked lateral density structure. During neap tides, there was a recirculation consisting of inflow in the northern half of the estuary and net outflow at the surface and net inflow at the bottom in the southern half of the estuary. The recirculation at the mouth is intensified during wet periods due to intense river discharge. The along-estuary dynamics is that proposed by the theory, between pressure gradient and friction.
DE: 4200 OCEANOGRAPHY: GENERAL
DE: 4217 Coastal processes
DE: 4223 Descriptive and regional oceanography
DE: 4227 Diurnal, seasonal, and annual cycles (0438)
DE: 4235 Estuarine processes (0442)
SC: Ocean Sciences [OS]
MN: 2007 Joint Assembly