Spatial and temporal statistics of sea surface temperature and chlorophyll fronts in the California Current

SUMMARY We created a consistent quantitative time series of thesea-surface fronts detected from satellite-detected datasets of SST and Chl for the domain of the CaliforniaCurrent (16–458N, 140–1008W) that is 29 years longfor SST and 14 years long for Chl. While the methodsused here for front detection are objective, the resultsdepend on a multitude of details of application and onthe type and quality of satellite data being used. In spiteof these shortcomings, we believe that the time series offrontal frequencies are objective characteristics of thesystem. Because of the extensive and frequent cloudcover, we had to composite (average) the daily distribu-tions of fronts into monthly mean distributions normal-ized by the number of cloud-free images. Thesemonthly time series of front frequencies have a signifi-cant error component due to missing data, and theerror is bigger offshore where the frequency of cloud-free days is lower.In this region, major SST fronts always coincide withChl fronts, but the across-front contrast is variable forSST and Chl. Therefore, not all SST fronts are detectedas Chl fronts, and vice versa. Compounded with the dif-ferent coverage of various satellite sensors, this producesdifferent spatial and temporal statistics for the SST andChl fronts. While both SST and Chl fronts are affected

[1]  James C. McWilliams,et al.  North Pacific Gyre Oscillation links ocean climate and ecosystem change , 2008 .

[2]  K. Wolter,et al.  Measuring the strength of ENSO events: How does 1997/98 rank? , 1998 .

[3]  Thomas M. Smith,et al.  Improved Extended Reconstruction of SST (1854–1997) , 2004 .

[4]  B. Franz,et al.  Examining the consistency of products derived from various ocean color sensors in open ocean (Case 1) waters in the perspective of a multi-sensor approach , 2007 .

[5]  L. Alberotanza,et al.  Oceanography from space, revisited , 2010 .

[6]  Adriana Huyer,et al.  The nature of the cold filaments in the California Current system , 1991 .

[7]  Jean-Francois Cayula,et al.  Geographic Window Sizes Applied to Remote Sensing Sea Surface Temperature Front Detection , 2002 .

[8]  Hiroshi Kawamura,et al.  Detection method of the Kuroshio front using the satellite-derived chlorophyll-a images , 2005 .

[9]  M. Kahru,et al.  Ocean Color Chlorophyll Algorithms for SEAWIFS , 1998 .

[10]  Peter Cornillon,et al.  Comparative study of two recent edge-detection algorithms designed to process sea-surface temperature fields , 1991, IEEE Trans. Geosci. Remote. Sens..

[11]  J. Wallace,et al.  A Pacific Interdecadal Climate Oscillation with Impacts on Salmon Production , 1997 .

[12]  Peter Cornillon,et al.  Satellite-derived sea surface temperature fronts on the continental shelf off the northeast U.S. coast , 1999 .

[13]  R. Legeckis,et al.  A survey of worldwide sea surface temperature fronts detected by environmental satellites , 1978 .

[14]  B. Håkansson,et al.  Distributions of the sea-surface temperature fronts in the Baltic Sea as derived from satellite imagery , 1995 .

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

[16]  Timothy P. Mavor,et al.  Sea surface temperature fronts in the California Current System from geostationary satellite observations , 2006 .

[17]  R. Bernstein,et al.  California Current Eddy Formation: Ship, Air, and Satellite Results , 1977, Science.

[18]  M. Kahru,et al.  Seasonal and nonseasonal variability of satellite‐derived chlorophyll and colored dissolved organic matter concentration in the California Current , 2001 .

[19]  Libe Washburn,et al.  The evolving structure of an upwelling filament , 1985 .

[20]  Andrew M. Fischer,et al.  Recurrent frontal slicks of a coastal ocean upwelling shadow , 2010 .

[21]  W. Scott Pegau,et al.  Ocean color observations of eddies during the summer in the Gulf of California , 2002 .

[22]  Peter Cornillon,et al.  Fronts in Large Marine Ecosystems , 2009 .

[23]  John E. O'Reilly,et al.  An algorithm for oceanic front detection in chlorophyll and SST satellite imagery , 2009 .

[24]  M. Bowman,et al.  Oceanic Fronts in Coastal Processes , 1978 .

[25]  I. Belkin.  Observational studies of oceanic fronts , 2009 .

[26]  J. Largier,et al.  Observations of increased wind‐driven coastal upwelling off central California , 2010 .

[27]  Peter Cornillon,et al.  Edge Detection Algorithm for SST Images , 1992 .

[28]  Sarah H. Peckinpaugh,et al.  Edge detection applied to satellite imagery of the oceans , 1989 .

[29]  Gilles Reverdin,et al.  Global high-resolution mapping of ocean circulation from TOPEX/Poseidon and ERS-1 and -2 , 2000 .

[30]  John P. Ryan,et al.  Mass Stranding of Marine Birds Caused by a Surfactant-Producing Red Tide , 2009, PloS one.

[31]  J. Yoder,et al.  Spatial variability in SeaWiFS imagery of the South Atlantic bight as evidenced by gradients (fronts , 2004 .

[32]  G. Forster,et al.  Summer phytoplankton blooms and red tides along tidal fronts in the approaches to the English Channel , 1975, Nature.

[33]  M. Kahru,et al.  Plankton distributions and processes across a front in the open Baltic Sea , 1984 .

[34]  C. Mooers,et al.  Prograde and Retrograde Fronts , 1978 .

[35]  Henri Weimerskirch,et al.  The importance of oceanographic fronts to marine birds and mammals of the southern oceans , 2009 .

[36]  R. Reynolds,et al.  The NCEP/NCAR 40-Year Reanalysis Project , 1996, Renewable Energy.

[37]  W. Hamner,et al.  Phalaropes feeding at a coastal front in Santa Monica Bay, California , 2002 .