Penetration of buoyancy driven current due to a wind forced river plume
MetadataShow full item record
The long term response of a plume associated with freshwater penetration into ambient, ocean water under upwelling favorable winds is studied using the Regional Ocean Modeling System (ROMS) in an idealized domain. Three different cases were examined, including a shore perpendicular source and shore parallel source with steady winds, and a shore perpendicular source with oscillating alongshore winds. Freshwater flux is used to define plume penetration. Alongshore penetration of buoyant currents is proportional to freshwater input and inversely proportional to upwelling wind stress strength. Strong wind more quickly prevents fresh water’s penetration. Under upwelling favorable winds, the plume is advected offshore by Ekman transport as well as upcoast by the mean flow. This causes the bulge to detach from the coast and move to upcoast and offshore with a 45 degree angle. The path of the bulge is roughly linear, and is independent of wind strength. The bulge speed has a linear relationship with the wind stress strength, and it matches the expected speed based on Ekman theory. Sinusoidal wind leads to sequential upwelling and downwelling events. The plume has an asymmetric response to upwelling and downwelling and fresh water flux is changed immediately by wind. During downwelling, the downcoast fresh water transport is greatest, while it is reduced during upwelling. Background mean flow in the downcoast direction substantially increases alongshore freshwater transport.
Baek, Seong-Ho (2006). Penetration of buoyancy driven current due to a wind forced river plume. Doctoral dissertation, Texas A&M University. Available electronically from