NBIA Colloquium via Zoom by Sune Olander Rasmussen (NBI)

Abrupt Climate Changes and Greenland Ice Cores

Speaker: Sune Olander Rasmussen (NBI)

Abstract: The Niels Bohr Institute has been among the world's leading institutions since the start of ice-core research, and NBI's professor Willi Dansgaard (1922-2011) pioneered the use of oxygen isotope measurements as tools in climate science. His name is also attached to the most prominent examples of abrupt climate changes in recent geological time: The so-called Dansgaard-Oeschger events, characterized by temperature changes in Greenland of 5-16 °C, often taking place in decades. The talk will briefly introduce ice-core drilling in a NBI-centric historical context and argue why ice-cores are ideal archives of past climate change. The talk will then present new high-resolution analyses of ice-core data and comprehensive climate model simulations which provide a lot of information about the anatomy and dynamics of the Dansgaard-Oeschger events, but also raise new questions about the nature of these changes.

Bio-sketch: Sune Olander Rasmussen holds a PhD in geophysics from NBI (2006). After being the coordinator at the DNRF Centre of excellence for Ice and Climate in 2007-2017, he was tenured at NBI and received a Carlsberg Foundation Distinguished Associate Professorship. He works at the cross-section of palaeoclimate stratigraphy and dating, signal analysis, and climate data analysis. Sune played a key role in the development of ice-core stratigraphy and chronology methods and tools, as well as methods and tools for synchronization of records from ice cores and other climate data archives. He also led the EU-funded COST Action INTIMATE (INTegrating Ice core, MArine and TErrestrial records).