An entire year frozen into the Arctic Ocean. 600 people from 17 countries. The largest Arctic climate expedition ever…  In September 2019 the German research icebreaker Polarstern departed from Tromsø, Norway and parked next to a chunk of sea ice. The ship will freeze in and spend the next year drifting through the Arctic Ocean with the floe. Scientists aboard will scrutinize the interactions of ocean, ice and atmosphere, making their data accessible to colleagues around the world and taking climate and ecosystem research to the next level. The mission is spearheaded by the Alfred Wegener Institute (AWI) in Germany, and U.S. participation is funded largely by the National Science Foundation and Department of Energy. This blog features updates from Matthew Shupe, co-coordinator of the MOSAiC mission; his work is also published on AGU’s The Field blog. Read more from other participants here.