Paleoclimatologists have long suspected a correlation exists between abrupt temperature changes in Greenland and in Antarctica, but ice cores from the two locations weren’t detailed enough to link the changes in the two regions. A new ice core from Antarctica, however, directly correlates abrupt changes in Greenland’s climate over the last 150,000 years with counterpart changes in Antarctica — offering further indication that the two icy regions are connected by ocean currents in a sort of bipolar seesaw.

The European Project for Ice Coring in Antarctica (EPICA) team found that occasional spikes in temperature both upward and downward in Antarctica directly correspond to the timing of rapid jumps in Greenland temperatures. As Antarctica has gradually warmed, Greenland cooled. Likewise, as soon as Greenland’s temperatures started rising, temperatures in Antarctica started to fall, the researchers reported in the Nov. 9 Nature.

Climate models suggest that the roughly inverse relationship the EPICA team observed is the result of a large change in heat in the Atlantic, says Hubertus Fischer of the Alfred Wegener Institute for Polar and Marine Research Glaciology in Bremerhaven, Germany, lead author of the new study. And understanding how Atlantic currents have connected Greenland and Antarctica over the past 150,000 years may help researchers strengthen climate models that project future slowdowns or shutdowns of the Atlantic currents, says Eric Wolff of the British Antarctic Survey in Cambridge, United Kingdom.

Margaret Putney
Geotimes contributing writer

For more about the ice core and what it reveals, read the original story posted online Nov. 10, 2006, in the Geotimes Web Extra archive at: www.geotimes.org/WebextraArchive.html.

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