A new chronology for Antarctic ice cores has been constructed based on the ratio of oxygen to nitrogen molecules in air trapped in the ice. This seems to reflect changes in local summer insolation, and thus allows the relative timing of changes in insolation and Antarctic climate to be determined. The results show that orbital-scale Antarctic climate change lagged Northern Hemisphere insolation over the past 360,000 years, and that increases in Antarctic temperature at the last four glacial-interglacial transitions took place within phases of increasing Northern Hemisphere insolation.
- Kenji Kawamura
- Frédéric Parrenin
- Okitsugu Watanabe
