Northern Monterey Bay upwelling shadow front : observations of a coastally and surface-trapped buoyant plume
Woodson, C. B.
Barth, John A.
Hoover, D. J.
Kirincich, Anthony R.
McManus, M. A.
Ryan, John P.
MetadataShow full item record
During the upwelling season in central California, northwesterly winds along the coast produce a strong upwelling jet that originates at Point Año Nuevo and flows southward across the mouth of Monterey Bay. A convergent front with a mean temperature change of 3.77 ± 0.29°C develops between the warm interior waters and the cold offshore upwelling jet. To examine the forcing mechanisms driving the location and movement of the upwelling shadow front and its effects on biological communities in northern Monterey Bay, oceanographic conditions were monitored using cross-shelf mooring arrays, drifters, and hydrographic surveys along a 20 km stretch of coast extending northwestward from Santa Cruz, California, during the upwelling season of 2007 (May–September). The alongshore location of the upwelling shadow front at the northern edge of the bay was driven by: regional wind forcing, through an alongshore pressure gradient; buoyancy forces due to the temperature change across the front; and local wind forcing (the diurnal sea breeze). The upwelling shadow front behaved as a surface-trapped buoyant current, which is superimposed on a poleward barotropic current, moving up and down the coast up to several kilometers each day. We surmise that the front is advected poleward by a preexisting northward barotropic current of 0.10 m s−1 that arises due to an alongshore pressure gradient caused by focused upwelling at Point Año Nuevo. The frontal circulation (onshore surface currents) breaks the typical two-dimensional wind-driven, cross-shelf circulation (offshore surface currents) and introduces another way for water, and the material it contains (e.g., pollutants, larvae), to go across the shelf toward shore.
Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 114 (2009): C12013, doi:10.1029/2009JC005623.
Suggested CitationArticle: Woodson, C. B., Washburn, Libe, Barth, John A., Hoover, D. J., Kirincich, Anthony R., McManus, M. A., Ryan, John P., Tyburczy, Joe, "Northern Monterey Bay upwelling shadow front : observations of a coastally and surface-trapped buoyant plume", Journal of Geophysical Research 114 (2009): C12013, DOI:10.1029/2009JC005623, https://hdl.handle.net/1912/3607
Showing items related by title, author, creator and subject.
Scaling for turbulent viscosity of buoyant plumes in stratified fluids : PIV measurement with implications for submarine hydrothermal plume turbulence Zhang, Wei; He, Zhiguo; Jiang, Houshuo (2017-10-07)Time-resolved particle image velocimetry (PIV) has been used to measure instantaneous twodimensional velocity vector fields of laboratory-generated turbulent buoyant plumes in linearly stratified saltwater over extended ...
Spall, Michael A.; Thomas, Leif N. (American Meteorological Society, 2016-10-07)Downfront, or downwelling favorable, winds are commonly found over buoyant coastal plumes. It is known that these winds can result in mixing of the plume with the ambient water and that the winds influence the transport, ...
Near-field iron and carbon chemistry of non-buoyant hydrothermal plume particles, Southern East Pacific Rise 15°S Hoffman, Colleen L.; Nicholas, Sarah L.; Ohnemus, Daniel C.; Fitzsimmons, Jessica N.; Sherrell, Robert M.; German, Christopher R.; Heller, Maija Iris; Lee, Jong-mi; Lam, Phoebe J.; Toner, Brandy M. (2018-01)