HR: 1340h
AN: OS13A-0520    [Abstracts]
TI: The time varying structure of a river plume: Observations with an autonomous glider.
AU: * Chant, R J
EM: chant@marine.rutgers.edu
AF: Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901 United States
AU: GLenn, S M
EM: glenn@marine.rutgers.edu
AF: Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901 United States
AU: Gong, D
EM: donglai@marine.rutgers.edu
AF: Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901 United States
AB: During the 2004 LaTTE (Lagrangian Transport and Transformation Experiment) pilot study we deployed a Slocum Autonomous glider on a 10-day mission to run repeated transects across the Hudson River Plume in the vicinity of Sandy Hook. The glider completed 13 cross-plume surveys during the mission with horizontal resolution of approximately 100 meters. Wind forcing was highly variable and fluctuated between upwelling and downwelling conditions at 1-2 day intervals. Tidal forcing decreased markedly from spring to neap tide conditions and river discharge averaged approximately 500 m3/s during the survey. The plume responded rapidly to the variable wind forcing. During upwelling conditions the plume thinned and extended over 30 km from shore, while during downwelling winds the plume thickened and was compressed at the shore. However, during both upwellling and downwelling conditions the plume remained detached from the bottom. The cross-sectional area of the plume also tended to vary with the wind forcing. However, a significant increase in the plume's area during the last half of the mission does not appear to be related to either wind forcing or river discharge. Instead, we suggest that the plumes structure could be impacted by spring neap variability which is known to control stratification and freshwater fluxes out of the Hudson River Estuary. This presentation will relate the structure of the plume to wind forcing, river flow and the spring/neap cycle.
DE: 4235 Estuarine processes
DE: 4279 Upwelling and convergences
DE: 4283 Water masses
DE: 4294 Instruments and techniques
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting