An empirical orthogonal function analysis of remotely sensed sea surface temperature variability and its relation to interior oceanic processes off Baja California

Abstract Empirical orthogonal function (EOF) analysis was applied to a 4.6-year sequence of AVHRR images off Baja California centered near Punta Eugenia to examine large-and mesoscale processes in this region of the California Current System (CCS). The mean structure found in the image sequence describes the seasonal cycle in sea surface temperature (SST) and the large-scale, north-south, oceanic SST gradient of the region. The first EOF-amplitude pair also describes the seasonal cycle in SST. Both results are consistent with long-term, large-scale, mean shipboard data for the region. The second EOF-amplitude pair defines two distinct regions paralleling the coast. The inshore region coincides with the coastal zone of Lynn and Simpson (1987), and the adjacent region farther offshore is identical to their transition zone . The third through fifth EOF-amplitude pairs primarily represent meandering of the California Current and anticyclonic mesoscale eddy occurrences in the region; these results also are consonant with a large number of shipboard observations. The EOF results provide independent satellite-derived evidence for the existence of a transition zone off Baja California which is similar to that found off central and southern California. Moreover, the agreement between the satellite-based results and the shipboard observations indicates that satellite data can be used successfully to study other current systems (e.g., Peru Current), where in situ observations (ships, buoys) are less abundant.

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

[2]  H. Hotelling.  Analysis of a complex of statistical variables into principal components. , 1933 .

[3]  James J. Simpson,et al.  An offshore eddy in the California current system Part I: Interior dynamics , 1984 .

[4]  M. Richman,et al.  Rotation of principal components , 1986 .

[5]  Anil K. Jain.  Fundamentals of Digital Image Processing , 2018, Control of Color Imaging Systems.

[6]  Paul C. Fiedler,et al.  Surface manifestations of subsurface thermal structure in the California Current , 1988 .

[7]  R. Woodman,et al.  Evaluation of effective eddy diffusive coefficients using radar observations of turbulence in the stratosphere , 1984 .

[8]  W. Liu,et al.  Bulk Parameterization of Air-Sea Exchanges of Heat and Water Vapor Including the Molecular Constraints at the Interface , 1979 .

[9]  R. Preisendorfer,et al.  A Significance Test for Principal Components Applied to a Cyclone Climatology , 1982 .

[10]  James J. Simpson,et al.  El Nino‐induced onshore transport in the California Current during 1982‐1983 , 1984 .

[11]  J. S. Godfrey,et al.  The Large-Scale Environment of the Poleward-Flowing Leeuwin Current, Western Australia: Longshore Steric Height Gradients, Wind Stresses and Geostrophic Flow , 1985 .

[12]  Michael B. Richman,et al.  Climatic Pattern Analysis of Three- and Seven-Day Summer Rainfall in the Central United States: Some Methodological Considerations and a Regionalization , 1985 .

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

[14]  James J. Simpson,et al.  Small-Scale Sea Surface Temperature Structure , 1980 .

[15]  R. Preisendorfer,et al.  Principal Component Analysis in Meteorology and Oceanography , 1988 .

[16]  James J. Simpson,et al.  An automated cloud screening algorithm for daytime advanced very high resolution radiometer imagery , 1990 .

[17]  James J. Simpson,et al.  A mesoscale eddy dipole in the offshore California Current , 1990 .

[18]  Ingemar Holmström,et al.  On a method for parametric representation of the state of the atmosphere , 1963 .

[19]  G. Forsythe,et al.  Computer solution of linear algebraic systems , 1969 .

[20]  J. J. Simpson,et al.  The temperature difference across the cool skin of the ocean , 1981 .

[21]  T. W. Anderson.  ASYMPTOTIC THEORY FOR PRINCIPAL COMPONENT ANALYSIS , 1963 .

[22]  J. Simpson,et al.  Temperature—plant pigment—optical relations in a recurrent offshore mesoscale eddy near Point Conception, California , 1986 .

[23]  Philip E. Gill,et al.  Numerical Linear Algebra and Optimization , 1991 .

[24]  H. Hotelling.  Relations Between Two Sets of Variates , 1936 .

[25]  J. Simpson,et al.  The flow of the undercurrent over the continental borderland off southern California , 1990 .

[26]  Ingemar Holmström,et al.  Analysis of time series by means of empirical orthogonal functions , 1970 .

[27]  A. Leetmaa,et al.  The Influence of Deep Mesoscale Eddies on Sea Surface Temperature in the North Atlantic Subtropical Convergence , 1976 .

[28]  S. Pond,et al.  Introductory Dynamical Oceanography , 1983 .

[29]  James J. Simpson,et al.  Automated cloud screening of AVHRR imagery using split-and-merge clustering☆ , 1991 .

[30]  John J. Walton,et al.  Principal components analysis of vector wind measurements , 1978 .

[31]  Alston S. Householder,et al.  Handbook for Automatic Computation , 1960, Comput. J..

[32]  James J. Simpson,et al.  An offshore eddy in the California current system part II: Surface manifestation , 1984 .

[33]  J. O'Brien,et al.  Empirical orthogonal function analysis of cloud-containing coastal zone color scanner images of northeastern North American coastal waters , 1989 .

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

[35]  James J. Simpson,et al.  A simple model of the 1982‐83 Californian "El Nino" , 1984 .

[36]  D. Chelton.  Seasonal variability of alongshore geostrophic velocity off central California , 1984 .

[37]  G. Swaters,et al.  Topographically-Induced Baroclinic Eddies near a Coastline, with Application to he Northeast Pacific , 1985 .

[38]  James J. Simpson,et al.  Response of the Southern California current system to the mid‐latitude North Pacific coastal warming events of 1982–1983 and 1940–1941 , 1992 .

[39]  T. P. Barnett,et al.  Scales of Thermal Variability in the Tropical Pacific , 1980 .

[40]  Kathryn A. Kelly,et al.  The influence of winds and topography on the sea surface temperature patterns over the northern California slope , 1985 .

[41]  James J. Simpson,et al.  On the accurate detection and enhancement of oceanic features observed in satellite data , 1990 .

[42]  James J. Simpson,et al.  Image masking using polygon fills and morphological transformations , 1992 .