Predictability of Dansgaard-Oeschger events in the Greenland ice core ensemble

It is an ongoing debate whether the abrupt climate changes during the last glacial interval, the so-called Dansgaard-Oeschger (DO) events, are solely due to stochastic fluctuations or a result of bifurcations in the structural stability of the climate. This raises the question whether they are predictable, and thus whether early warning signals for the abrupt transitions from Greenland stadial to interstadial periods could be observed.

Here, we propose a new method to analyze the DO events between 60 ka before present and the Holocene, where we look at the ensemble of oxygen isotope ratio (δ¹⁸O) measurements from three different Greenland ice cores. For each rapid transition from a Greenland stadial to interstadial period, the three time series are normalized and scaled individually. The goal is to determine whether early warning signals in the further detrended ensemble are observable and thus to contribute to the ongoing debate whether past abrupt climate change has been purely noise-induced or a result of changed stability in the climate system.