Recent Decadal Variation in the California Current System

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  • 1 Scripps Institutions of Oceanography, University of California, San Diego, La Jolla 92037
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Abstract

A study has been made to identify the existence of different decadal climatic regimes before and after the anomalous environmental changes that occurred in 1958. Atmospheric and oceanographic data in the California Current System near San Diego were processed and used for the computation of all oceanic mass transport components. Evidence shows that distinguishable climatic regimes did exist and that in the period of 1957–58 abrupt anomalous variations marked the break between two successive quasi-stable decadal regimes. As the result of overall differences in atmospheric circulation between these two regimes, it is found that there was stronger eastward flow and weaker southward flow in the California Current System near the San Diego area during the present decade than in the previous decade. The direct result of differences in mass transports was to bring more warm and high salinity subtropic water and less cold and low salinity subarctic water into the area of study. These consequences were evidenced by oceanographic and atmospheric field observations. Differences in temperature and salinity and differences in current flow account for the significant difference in San Diego sea level variations between the periods 1948–57 and 1958–69.

Abstract

A study has been made to identify the existence of different decadal climatic regimes before and after the anomalous environmental changes that occurred in 1958. Atmospheric and oceanographic data in the California Current System near San Diego were processed and used for the computation of all oceanic mass transport components. Evidence shows that distinguishable climatic regimes did exist and that in the period of 1957–58 abrupt anomalous variations marked the break between two successive quasi-stable decadal regimes. As the result of overall differences in atmospheric circulation between these two regimes, it is found that there was stronger eastward flow and weaker southward flow in the California Current System near the San Diego area during the present decade than in the previous decade. The direct result of differences in mass transports was to bring more warm and high salinity subtropic water and less cold and low salinity subarctic water into the area of study. These consequences were evidenced by oceanographic and atmospheric field observations. Differences in temperature and salinity and differences in current flow account for the significant difference in San Diego sea level variations between the periods 1948–57 and 1958–69.

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