Research Unit 1a (Topic 1)
The Polar Atmosphere and Cryosphere in a Changing Climate
Polar Regions are most strongly affected by climate change, yet they belong to the least studied parts of the Earth System. Understanding the role of high latitudes in the Earth System, for example their impact on sea-level, requires quantification of the contemporary variability and changes in the atmosphere and cryosphere, and their interaction with the polar ocean.
The key questions focus on the interaction of the polar atmosphere with sea ice, ocean and land, the controls on ice sheet mass balance, the cycling of the potent greenhouse gas methane, and the vulnerability of Arctic permafrost carbon pools. To address these questions, we use field and laboratory measurements, remote sensing, and numerical modelling with special emphasis on long-term observations. Through long-term observations of key atmospheric processes we achieved their implementation into global models, improving climate and northern weather prediction.
We found that basal melt, calving seasonality and internal structure of ice determine ice stream dynamics in Greenland, which motivated the first drilling project into an ice-stream. Ice-ocean modelling indicates irreversible warming in Antarctic shelves with strong impact on global sea-level. Permafrost thaw was found to strongly affect ecology, soil carbon pool stability, regional hydrology, and coastal erosion.