Patterns and Drivers of Southern Ocean Sea Ice Dynamics
(DFG, SPP Antarktisforschung, 2023-2026)
Given the key role that Antarctic sea ice plays in global climate, our understanding of processes, interactions and driving mechanisms for the observed and anticipated dynamics is still far from complete. During wintertime, the sea ice cover is characterized by the presence of sea-ice leads, i.e. linear cracks, where an interface between the relatively warm ocean and cold atmosphere is established. A previous study has provided insight into the spatial patterns of these leads around Antarctica and indicated that ocean currents and bathymetry play a major role in shaping the lead distribution. The PADOS project aims at closing the gap between the spatial scale at which leads occur and the scale at which pan-Antarctic and long-term data sets for sea ice are currently provided.
An updated data set of leads with a high spatial resolution (1 km²) in combination with data of polynya and fast ice dynamics will allow us to gain improved insight into the spatial and temporal dynamics of sea ice in the Southern Ocean as well as to identify drivers of these dynamics. Published findings that address the connection between sea-ice dynamics and atmosphere/ocean drivers are evaluated against our results and will be built upon to develop improved explanations and concise conceptual models for the forcing of sea-ice dynamics at the atmosphere and ocean interfaces. Research questions that are addressed in this context:
- How does the frequency, timing, path and strength of extratropical cyclones influence the lead fraction, ice edge and – potentially – vice versa?
- What is the role of winds for the overall sea-ice dynamics?
- How do bathymetry and ocean currents play together in causing long-term lead patterns?
- How do catabatic winds and embedded synoptic conditions influence the variability of fast ice areas as well as the timing and extent of polynya openings?
Dr. Sascha Willmes (PI)
Prof. Dr. Günther Heinemann
Dr. Stephan Paul (AWI)