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Wave breaking turbulence at the offshore front of the Columbia River Plume
Author(s) -
Thomson Jim,
HornerDevine Alex R.,
Zippel Seth,
Rusch Curtis,
Geyer W.
Publication year - 2014
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2014gl062274
Subject(s) - plume , front (military) , turbulence , submarine pipeline , breaking wave , geology , mixing (physics) , energy flux , scaling , panache , turbulence kinetic energy , wave setup , oceanography , atmospheric sciences , meteorology , wave propagation , physics , geometry , longitudinal wave , mathematics , quantum mechanics , astronomy , mechanical wave
Observations at the Columbia River plume show that wave breaking is an important source of turbulence at the offshore front, which may contribute to plume mixing. The lateral gradient of current associated with the plume front is sufficient to block (and break) shorter waves. The intense whitecapping that then occurs at the front is a significant source of turbulence, which diffuses downward from the surface according to a scaling determined by the wave height and the gradient of wave energy flux. This process is distinct from the shear‐driven mixing that occurs at the interface of river water and ocean water. Observations with and without short waves are examined, especially in two cases in which the background conditions (i.e., tidal flows and river discharge) are otherwise identical.