For ten months, the “Polarstern” drifted through the Arctic, docked to a huge ice floe. This made it possible to measure and document the entire ice cycle from freezing to melting.
In the journal “Elementa: Science of the Anthropocene”, the scientists have now published a complete picture of the climate processes in the central Arctic for the first time. This provides a tremendous resource for further studies to capture the climate feedbacks and global impacts of Arctic change.
The Arctic influences the climate worldwide
The Arctic is warming particularly quickly due to climate change. Hardly any other region on earth feels this more clearly, and thus influences weather and climate worldwide.
The Paul Scherrer Institute (PSI), the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), the Swiss Polar Institute (SPI) and the Swiss Commission for Polar and High Altitude Research (SKPH) were also involved in the “Mosaic” project. It was managed by the Bremerhaven Alfred Wegener Institute (AWI).
Insights into the carbon cycle and the radiation balance
One finding of the researchers is that the pack ice is drifting more dynamically and faster than expected. AWI marine physicist Marcel Nicolaus was quoted as saying in a statement that this would lead to changed sea properties and sea ice thickness distributions.
One reason: “Near the surface, there were particularly low temperatures in the winter months and the associated persistently strong winds, which intensified the ice drift and thus pushed the Polarstern faster than expected,” explained atmosphere researcher Matthew Shupe. Also, more than 20 arctic cyclones, or storms, of varying magnitude have been observed sweeping across the ice floe. These events were “described in unprecedented detail.”
In addition, the researchers managed to completely map the ocean eddies over a complete annual cycle and to document where and how the snow was deposited or swept away.
In addition, year-round data on atmospheric composition and aerosol variability would provide new insights into the relative impacts of long-range transport versus local processes. This has important effects on climate-relevant cycles such as the carbon cycle, clouds and the radiation balance, explained the marine physicist Nicolaus.
Swiss researchers study aerosols and snow
More than 600 researchers from 80 institutes in 20 countries were involved in the “Mosaic” expedition. The total costs amounted to around 158 million Swiss francs. It was the most expensive and logistically complex expedition in the Arctic Ocean to date.
Swiss researchers were also on board the “Polarstern” and are among the co-authors of the work that has now been published. Julia Schmale and her team from PSI, for example, researched the aerosols in the Arctic atmosphere, which are important for cloud formation.
David Wagner and his colleagues from the WSL Institute for Snow and Avalanche Research (SLF) investigated the role of snow in sea ice formation and melting. And the team led by Martin Schneebeli, also from the SLF, recorded the microstructures and physical properties of the snow using various measurement techniques.