Ongoing changes in the high-latitude oceans are a pressing topic of contemporary research. The Arctic Ocean, with its rapidly reducing summer sea ice extent, appears to be in a transition towards a seasonally ice-free ocean, with significant implications for marine biology and large-scale to global climate. An extraordinarily strong freshening of the upper ocean and a warming inflow from the Atlantic and Pacific oceans raise the question of feedback mechanisms between subarctic and Arctic oceans.
The Southern Ocean features equally complex interactions between the atmosphere, ocean, cryosphere and marine organisms, with significant impacts on the carbon cycle, regional ecosystems, the Antarctic ice sheet, and sea level rise. While sea ice changes are not as obvious as in the Arctic, the Southern Ocean is warming more rapidly than the global ocean mean. Progress in understanding the relevant interactions and feedback mechanisms to and from the ongoing global warming requires determining amplitude and timescales of variability through long-term observations in the remote and hostile polar oceans as well as refined numerical models.

Eberhard Fahrbach, who passed away on April 23, 2013, was one of the pioneers of long-term high-latitude ocean observations. His devotion to promoting multi-year studies was equally strong in the seasonally ice-covered Southern Ocean and in the Arctic and Subarctic seas. In both hemispheres, he provided the basis for time series that constitute a value increasing every year. To commemorate Eberhard’s contribution to understanding the polar oceans in a changing climate, this session calls together researchers addressing the state of and the changes in both polar oceans from observations as well as from model results. This includes smaller-scale and regional ocean studies just as well as basin-scale efforts. Studies of the polar oceans’ evolution and emerging ideas as to how it may be linked to subpolar changes are particularly encouraged.