HR: 1330h
AN: OS52A-0900    [PDF]
TI: Dispersal of Sediment in the Western Adriatic during Energetic Wintertime Forcing
AU: * Harris, C K
EM: ckharris@vims.edu
AF: Virginia Institute of Marine Science, Department of Physical Sciences, Gloucester Point, VA 23062 United States
AU: Sherwood, C R
EM: csherwood@usgs.gov
AF: U. S. Geological Survey, 384 Woods Hole Rd., Woods Hole, MA 02543
AU: Mullenbach, B L
EM: bmullenbach@ocean.tamu.edu
AF: Texas A&M University, Department of Oceanography, College Station, TX 77843-3146
AU: Pullen, J D
EM: pullen@nrlmry.navy.mil
AF: Naval Research Lab, Marine Meteorology Division, Monterey, CA 93943
AB: EuroSTRATAFORM aims to relate sediment delivery and reworking to seabed morphology and stratigraphy through observations and modeling of water column transport. The Po River dominates buoyancy and sediment input into the Adriatic Sea, but small Apeninne rivers (the Chienti, Pescara, etc.) may produce locally important signals. Sedimentation is influenced by fluvial supply, resuspension by waves and currents, and transport by oceanographic currents forced by winds and buoyancy. Transport is likely highest during times of energetic forcing; including Bora events with northeasterly winds and Sirocco events with southeasterly winds. It is difficult, from field measurements alone, to characterize dispersal and convergence patterns over the relevant spatial scales. We applied a three-dimensional hydrodynamic model that includes fluvial delivery, transport, resuspension, and deposition of sediment to quantify sediment dispersal with a 2-km resolution over the entire Adriatic. Circulation calculations were driven by spatially- and temporally-varying wind fields for the Fall / Winter of 2002 / 2003 and realistic Po and Apennine river discharges. Waves were hindcast with the SWAN model. Dispersion of both resuspended and river-derived sediment was estimated for periods that contained intense Bora and Sirocco winds. Predicted sediment dispersal rates and patterns are sensitive to forcing winds, buoyancy flux, and wave patterns. Higher sediment flux was predicted during Bora conditions than during Sirocco conditions. Sirocco winds weaken the Western Adriatic Coastal Current (WACC), and because they tend to concentrate over the Eastern Adriatic, they often fail to create especially energetic waves in the Western Adriatic. Bora wind conditions, on the other hand, intensify the WACC and can build high wave energies over the northwestern Adriatic. Most of the sediment transport occurs during Bora, with a net southward flux. These predictions will be compared to field observations made as part of the EuroSTRATAFORM experiment.
DE: 3022 Marine sediments--processes and transport
DE: 4219 Continental shelf processes
DE: 4255 Numerical modeling
DE: 4558 Sediment transport
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting