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.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-1174 |
| Date | 15 May 2009 |
| Creators | Baek, Seong-Ho |
| Contributors | Hetland, Robert D. |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | electronic, application/pdf, born digital |
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