Sea surface temperature anomalies near South Georgia: relationships with the Pacific El Nino regions

The data set of Reynolds and Smith [1994] is used to describe temporal variability in sea surface temperature (SST) at South Georgia. Time series analysis indicates that high levels of autocorrelation are present, with periodicity evident in temperature anomalies at lag periods of approximately 4 years. Cross-correlation analyses with data describing the El Nin˜o regions of the Pacific indicate that variability at South Georgia reflects temperature fluctuations in the Pacific. This relationship is temporally separated, with the Pacific leading South Georgia by approximately 3 years and with the west Pacific showing the strongest cross correlation. Historic data describing the west Pacific show that patterns of variability have evolved through time and that the strong 4 year periodicity evident in recent years was not present in earlier records. The correlation between the west Pacific and South Georgia has also varied through time and the relationship is currently weaker than it has been over the past 19 years. The results are discussed in the context of a circumpolar precession of anomalies, transferring variability from the Pacific into the Atlantic.