Holocene Southern Ocean surface temperature variability west of the Antarctic Peninsula

The Antarctic Peninsula is currently one of the fastest-warming locations on Earth, but its long-term variability has remained unclear. Amelia Shevenell and colleagues now use the TEX86 proxy, a palaeothermometer that tracks membrane lipids of the marine picoplankton Crenarchaeota, to show that a long-term cooling of about 4 °C occurred in waters near the tip of Antarctic Peninsula over the past 12,000 years. This is consistent with orbitally controlled changes in insolation. Shorter-term variability in temperature seems to have been strongly influenced by the position of the westerly winds. This work suggests that the present influence of the El-Nino Southern Oscillation system on the Antarctic Peninsula is a relatively recent phenomenon, dating to the late Holocene.