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Climate Connections

Forecasting long-term climate variability has been challenging in the Pacific Ocean, but findings by a researcher at the University of Texas at Austin’s Institute for Geophysics could help future efforts.

Slow changes in sea surface temperatures in the tropical Pacific Ocean are known to affect the atmospheric circulation and hydrological cycle around the world, including Texas. A new study by research associate Yuko Okumura indicates that Pacific decadal variability originates in the South Pacific, not the North Pacific. The findings have important implications for long-term climate monitoring and predictions.

Previous studies of Pacific decadal variability have paid more attention to the North Pacific, partly because historical ocean-atmosphere data is more abundant in the North than the South Pacific. The new analysis, however, indicates that random atmospheric variability over the South Pacific Ocean modifies sea surface temperatures in the southeast tropical Pacific, which in turn affect the North Pacific Ocean through atmospheric teleconnections.

The findings were published in the American Meteorological Society online journal in December 2013. The strong decadal linkage between the tropical Pacific and South Pacific  is also supported by Okumura’s previous analysis of tropical coral and Antarctic ice core records from the past two centuries.