Arctic Sea ice: Microstructure and geophysical processes

Dr Hajo Eicken, Scientific Director of the Alfred Wegener Institute.

Sea ice

snow

Arctic

 glaciology

Sea-ice geophysics is a central research field within polar and climate sciences. Sea ice covers large parts of the Arctic and Antarctic and plays a key role in the Earth system by linking physical, ecological, and climatic processes.

A particular research focus lies on the small-scale physical properties and microstructure of sea ice, including crystal structure, pore spaces, and salinity. These characteristics determine how heat, light, and nutrients are transported within the ice and how it responds to external influences such as temperature changes and ocean currents. Although these processes occur on very small spatial scales, they strongly affect the growth, stability, and decay of sea ice and thereby influence both Arctic ecosystems and large-scale feedbacks within the climate system.

Beyond its role as a physical component of the climate system, sea ice is also considered in terms of its multiple functions. It contributes significantly to the cooling of the planet through the reflection of incoming solar radiation and simultaneously provides habitat for animals and microbial life.

Against this background, the study of geophysical processes in sea ice is of central importance for understanding ongoing changes in the polar regions. It provides essential foundations for assessing the role of sea ice in the climate system, its ecological function, and its future relevance for human use.