Specialty

Paleoclimate, ice cores, abrupt climate change, firn processes

Research Interests

My work aims to reconstruct and understand past climate change and atmospheric composition, using deep ice cores from Greenland and Antarctica. I combine ice core measurements, numerical modeling and fieldwork to achieve these goals.

I have an enduring interest in abrupt climate change of the last ice age, the so-called Dansgaard-Oeschger cycle. For each D-O event, Greenland warmed by about 10°C within decades. We discovered that during these events the hemispheres communicate via slow (200 year delayed!) oceanic signals, as well as via fast atmospheric signals. Using climate models I have investigated the role of the Southern Ocean in setting the pace of the D-O cycle.

Ongoing work is to reconstruct the timing, magnitude and spatial pattern of climate change over the Greenland ice sheet using nitrogen isotopes, and to understand how this relates to the rate of ice retreat during the last deglaciation.

I have extensively studied the firn layer, which is the 50 to 100 m thick layer of unconsolidated snow on top of ice sheets. I work both on firn densification and on firn air transport.

Ice core timescales (or chronologies) are critical for the correct interpretation of ice core records. I continue to work on improving ice core chronologies through firn densification modeling and volcanic matching. I have contributed to ice core time scales of the NEEM, GISP2, WAIS Divide, South Pole and RICE ice cores.

Other research projects include radiometric Kr-81 dating of ancient ice in Antarctica, in situ radiocarbon production in ice, and the relationship between temperature and accumulation in Antarctica. In a previous life, I worked on quantum dots and spintronics.

Education

BSc in physics, Delft University of Technology, Netherlands (2004)
MSc in physics, Delft University of Technology, Netherlands (2007)
PhD in geophysics, Niels Bohr Institute, University of Copenhagen, Denmark (2012)

Courses

GEO 308 – Global change and Earth sciences

Projects and Collaborations

North Greenland Eemian Ice Drilling (NEEM) ice core
West Antarctic Ice sheet (WAIS) Divide ice core
South Pole ice core (SPICEcore)
Roosevelt Island Climate Evolution (RICE) ice core

Graduate research projects

Interested in pursuing graduate research in paleoclimate or ice core research? Please contact me for ongoing projects and graduate research opportunities.

Publications

Please see my Google Scholar profile for my publication list, or hit me up on Researchgate.

Stories

October 23, 2024 - OSU Newsroom, New ice core data provides insight into climate ‘tipping points’ during the last Ice Age