Satellite observations of small coastal ocean eddies in the Southern California Bight

This study describes the characteristics of extensive small-scale coastal ocean eddies in the Southern California Bight. These surface features were primarily detected by using ERS-1 and ERS-2 synthetic aperture radar (SAR) satellite imagery from 1992 to 1998. The eddies, predominantly cyclonic in their rotation, appeared to result from several forcing mechanisms. They were mainly observed within the Santa Barbara Channel and the Santa Monica-San Pedro Basin regions and appeared to be seasonal in their distribution. Observed eddy diameters were all less than 50 km, with over 70% less than 10 km. The SAR data were complemented by sea surface temperature measurements derived from advanced very high resolution radiometer satellite imagery, as well as in situ data from moorings and drifters that provided substantial verification of the small-scale eddies. These findings are significant in that the eddies were, in general, smaller in size and more abundant than previously reported. Additionally, these results provide further evidence of the complex near-surface circulation within the Southern California Bight, with important implications for nutrient flux, productivity, plankton patchiness, larval transport and recruitment, and dispersal of pollutants.

[1]  Lee-Lueng Fu,et al.  Some examples of detection of oceanic mesoscale eddies by the SEASAT synthetic‐aperture radar , 1983 .

[2]  Derek C. Quigley,et al.  The world's most spectacular marine hydrocarbon seeps (Coal Oil Point, Santa Barbara Channel, California): Quantification of emissions , 1999 .

[3]  R. Murdoch.  The effects of a headland eddy on surface macro-zooplankton assemblages North of Otago Peninsula, New Zealand , 1989 .

[4]  Salvatore Marullo,et al.  Observations of a small-scale baroclinic eddy in the Ligurian Sea , 1985 .

[5]  W. Hamner,et al.  Regularly spaced rows of medusae in the Bering Sea: Role of Langmuir circulation1 , 1986 .

[6]  Ola M. Johannessen,et al.  Satellite detection of natural films on the ocean surface , 1996 .

[7]  David L. Jones,et al.  Translocation of larval coral reef fishes via sub-mesoscale spin-off Eddies from the Florida current , 1997 .

[8]  Paris W. Vachon,et al.  Coastal ocean fronts and eddies imaged with ERS 1 synthetic aperture radar , 1996 .

[9]  Kenneth H. Brink,et al.  Circulation in the Point Conception‐Santa Barbara Channel region , 1986 .

[10]  Johnny A. Johannessen,et al.  Eddies detected in ERS-1 SAR images and simulated in reduced gravity model , 1993 .

[11]  Gary S. E. Lagerloef,et al.  Empirical orthogonal function analysis of advanced very high resolution radiometer surface temperature patterns in Santa Barbara Channel , 1988 .

[12]  J. Largier,et al.  Demonstration of the onshore transport of larval invertebrates by the shoreward movement of an upwelling front , 2000 .

[13]  M. Kingsford.  Linear oceanographic features: a focus for research on recruitment processes , 1990 .

[14]  M. Kingsford,et al.  Influence of surface slicks on the distribution and onshore movements of small fish , 1986 .

[15]  A. Münchow.  Wind Stress Curl Forcing of the Coastal Ocean near Point Conception, California* , 2000 .

[16]  Walter Munk,et al.  Spirals on the sea , 2000, Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[17]  A. Shanks,et al.  The Onshore Transport of an Oil Spill by Internal Waves , 1987, Science.

[18]  M. Tsuchiya.  Inshore circulation in the Southern California Bight, 1974–1977 , 1980 .

[19]  M. Collins,et al.  Island wakes and headland eddies: A comparison between remotely sensed data and laboratory experiments , 1987 .

[20]  B. Hickey.  Variability in two deep coastal basins (Santa Monica and San Pedro) off southern California , 1991 .

[21]  Ola M. Johannessen,et al.  Synthetic aperture radar imaging of upper ocean circulation features and wind fronts , 1991 .

[22]  S. Tanabe,et al.  Persistent organochlorines in coastal fronts , 1991 .

[23]  James C. McWilliams,et al.  Submesoscale, coherent vortices in the ocean , 1985 .

[24]  C. Dorman,et al.  The Structure and Variability of the Marine Atmosphere around the Santa Barbara Channel , 2000 .

[25]  R. Manasseh,et al.  Recirculation in the lee of complicated headlands: A case study of Bass Point , 1995 .

[26]  J. Simpson,et al.  The effects of flow disturbance by an oceanic island , 1990 .

[27]  Francis P. Bretherton,et al.  Atmospheric Frontogenesis Models: Mathematical Formulation and Solution , 1972 .

[28]  R. Perissinotto,et al.  Occurrence of anticyclonic eddies on the Prince Edward Plateau (Southern Ocean): effects on phytoplankton biomass and production , 1990 .

[29]  James J. Simpson,et al.  The California Current system: The seasonal variability of its physical characteristics , 1987 .

[30]  P. Poulain,et al.  Statistical Analysis of the Surface Circulation in the California Current System Using Satellite-Tracked Drifters , 1989 .

[31]  Thomas N. Lee.  Florida current spin-off eddies , 1975 .

[32]  R. Davis,et al.  Mesoscale hydrographic variability in the vicinity of Points Conception and Arguello during April–May 1983: The OPUS 1983 experiment , 1986 .

[33]  B. Holt,et al.  SEASAT views oceans and sea ice with synthetic aperture radar , 1982 .

[34]  Diane L. Evans,et al.  Overview of results of Spaceborne Imaging Radar-C, X-Band Synthetic Aperture Radar (SIR-C/X-SAR) , 1995, IEEE Trans. Geosci. Remote. Sens..

[35]  P. Tildesley,et al.  Imaging of oceanic features by ERS 1 synthetic aperture radar , 1995 .

[36]  C. Dorman.  Winds between San Diego and San Clemente Island , 1982 .

[37]  P. Scully-Power.  Navy Oceanographer Shuttle Observations, STS 41-G Mission Report , 1986 .

[38]  J. Sigoillot,et al.  Organic matter composition and pollutant enrichment of sea surface microlayer inside and outside slicks , 1993 .

[39]  R. Falconer,et al.  Eddy Formation Behind a Coastal Headland , 1995 .

[40]  P. Falkowski,et al.  Role of eddy pumping in enhancing primary production in the ocean , 1991, Nature.

[41]  Antony K. Liu,et al.  Wave‐current interaction study in the Gulf of Alaska for detection of eddies by synthetic aperture radar , 1994 .

[42]  J. Tintoré,et al.  Three-dimensional circulation of a mesoscale eddy/front system and its biological implications , 1995 .

[43]  M. Hendershott,et al.  Statistical aspects of surface drifter observations of circulation in the Santa Barbara Channel , 1998 .

[44]  E. D’Asaro.  Observations of small eddies in the Beaufort Sea , 1988 .

[45]  Winant,et al.  Surface Circulation in the Santa Barbara Channel , 1996 .

[46]  Ola M. Johannessen,et al.  COASTWATCH'95: ERS 1/2 SAR detection of natural film on the ocean surface , 1998 .

[47]  M. Hendershott,et al.  Near‐surface trajectories off central and southern California , 1999 .

[48]  K. Ohshima,et al.  Observations of Ice-Ocean Eddy Streets in the Sea of Okhotsk off the Hokkaido Coast Using Radar Images , 1990 .

[49]  Heinrich Hühnerfuss,et al.  Imaging of biogenic and anthropogenic ocean surface films by the multifrequency/multipolarization SIR‐C/X‐SAR , 1998 .

[50]  F. Garabétian,et al.  PHOTOGRAPHIC RECORDS OF SEA-SURFACE MICROLAYERS AS A SURVEY OF POLLUTION DAILY RHYTHM IN COASTAL WATERS , 1996 .

[51]  Ola M. Johannessen,et al.  Mesoscale eddies in the Fram Strait marginal ice zone during the 1983 and 1984 Marginal Ice Zone Experiments , 1987 .

[52]  Eric D. Barton,et al.  The influence of island-generated eddies on chlorophyll distribution : a study of mesoscale variation around Gran Canaria , 1997 .

[53]  P. Stabeno,et al.  A census of mesoscale eddies in Shelikof Strait, Alaska, during 1989 , 1994 .

[54]  K. Brink,et al.  Mesoscale Wind Variability near Point Conception, California during Spring 1983 , 1986 .

[55]  P. Stabeno,et al.  Characteristics of an eddy over a continental shelf: Shelikof Strait, Alaska , 1993 .

[56]  D. Siegel,et al.  Mesoscale Eddies, Satellite Altimetry, and New Production in the Sargasso Sea , 1999 .

[57]  R. Stewart,et al.  The observation of ocean surface phenomena using imagery from the SEASAT synthetic aperture radar: An assessment , 1982 .

[58]  H. Sverdrup.  On the Process of Upwelling , 1938 .

[59]  C. Winant,et al.  Characteristic patterns of the circulation in the Santa Barbara Channel , 1998 .

[60]  S. G. Salashin,et al.  Film slicks on the sea surface and some mechanisms of their formation , 1992 .

[61]  W. Hamner,et al.  Topographically Controlled Fronts in the Ocean and Their Biological Influence , 1988, Science.

[62]  L. Oey,et al.  “Upwelling” and “cyclonic” regimes of the near‐surface circulation in the Santa Barbara Channel , 2001 .

[63]  J. Priddle,et al.  Retention of phytoplankton by an eddy , 1987 .

[64]  S. Glenn,et al.  Observations of recurrent mesoscale eddies in the eastern Mediterranean , 1996 .

[65]  S. D. Soules.  Sun glitter viewd from space , 1970 .

[66]  R. Pingree.  Baroclinic eddies bordering the celtic sea in late summer , 1979, Journal of the Marine Biological Association of the United Kingdom.

[67]  Barbara M. Hickey,et al.  The California current system—hypotheses and facts☆ , 1979 .

[68]  C. Dorman,et al.  Seasonal patterns of surface wind stress and heat flux over the Southern California Bight , 1997 .

[69]  W. Johnson,et al.  Satellite photography of eddies in the Gulf Loop Current , 1974 .

[70]  N. Bray,et al.  The California Current system in the Southern California Bight and the Santa Barbara Channel , 1999 .

[71]  V. Klemas,et al.  Element enrichment in organic films and foam associated with aquatic frontal systems , 1972 .

[72]  M. Swenson,et al.  Statistical analysis of the surface circulation of the California Current , 1996 .

[73]  D. Stevens,et al.  Eddy formation behind the tropical island of Aldabra , 1996 .

[74]  B. Holt,et al.  Internal waves in the Gulf of California: Observations from a spaceborne radar , 1984 .

[75]  R. Signell,et al.  Transient eddy formation around headlands , 1991 .

[76]  J. G. Bruce.  Eddies southwest of the Denmark Strait , 1995 .

[77]  B. Hickey.  Circulation over the Santa Monica-San Pedro Basin and Shelf , 1992 .