To address this question, the NYU researchers focused on a different candidate: the Atlantic Ocean, which has been overlooked as a factor behind Antarctic climate change.
Specifically, the scientists looked at the North and Tropical Atlantic's Sea Surface Temperature (SST) variability--changes in the ocean's surface temperature--focusing on the last three decades. This metric, the Atlantic Multidecadal Oscillation, had previously not been considered in seeking explanations for Antarctic climate change.
Using a time-series analysis, in which the scientists matched changes in the North and tropical Atlantic's space-based SST data with subsequent changes in Antarctic climate, the researchers found strong correlations. Specifically, they observed that warming Atlantic waters were followed by changes in sea-level pressure in the Antarctic's Amundsen Sea. In addition, these warming patterns also preceded redistribution of sea ice between the Antarctic's Ross and Amundsen-Bellingshausen-Weddell Seas.
David Holland, co-author of the study, a professor at NYU's Courant Institute and past-director of NYU's Center for Atmospheric Ocean Science, explained that the research consisted of two parts, incorporating both observational data and computer modelling.
The first part of the study, using observational data, found a link, or correlation, between the Atlantic and Antarctic data sets. But a correlation means simply that two things appear to happen in conjunction and does not explain what may be causing a phenomenon.
|Contact: Peter West|
National Science Foundation