In the grip of the ice – The power of the Arctic Ocean

Quelle: 10 June 2015
by A. Fong, M. Kędra, and C. Mӓrz
Without light, life is not possible. Algae depend on the sun`s energy and can only grow if there is enough light penetrating the ocean. The depth at which light reaches is dependent on the various substances present in the water. If specific substances are abundant, the sea water turns yellow or even brown. Monika Zablocka and Justyna Meler are making measurements to find out how deep sunlight is reaching into the Arctic Ocean, what are its determinants and how it will change in the warming Arctic. While most sampling equipment is moved into the water by one of Polarstern's many cranes and winches, Monika and Justyna deploy their equipment from a zodiac boat at the sea ice edge.

Now steaming across the Arctic Ocean on a 118 meter long icebreaker, propelled by 20,000 horse-powers and steered by a highly experienced crew, one might think that such research efforts in this extremely remote landscape are just like anywhere else on the world’s oceans. Well, think again. As already mentioned in the previous blog, sea ice rules in the Arctic spring time and plans can fall apart as quickly as they are made. Just recently, we had some first-hand evidence of the power of sea ice.

Polarstern anchored alongside a lovely ice floe in the evening - just to discover by the morning that neighbouring ice floes had slowly but steadily moved in from two sides. Open water is needed to deploy instruments from the working deck – if there is not enough space some deployments have to be cancelled. More importantly, without enough open water surrounding, the ship can become entrapped by ice as it cannot gain sufficient momentum to break through. This was also the experience of the zodiac team: Their way back to the ship was blocked by a heavy ice drift and they had to enter the ice floe. The zodiac was eventually towed back to Polarstern using a Skidoo. Finally, the decision was made to get all scientists and equipment off the ice floe before Polarstern got permanently stuck. Scientists were lifted off the ice using the “mummy chair” and one of the ship’s cranes. Most scientists seemed to rather enjoy this evacuation experience, as the weather was sunny with almost no wind. Nevertheless, it once again showed that the Arctic Ocean is still a very wild and unpredictable environment, where humans are only guests and have to follow the rules of nature. After all, 20,000 horse-powers and 118 meters of solid steel have little to put up against millions of tons of frozen water.