Occasionally accompanied by polar bears, Lauriane Quéléver just spent three months on the research vessel Polarstern at the Arctic Ocean. Doctoral student in atmospheric sciences, Quéléver took part in the first leg of the year-long MOSAiC expedition. The largest polar expedition in history aims at making increasingly accurate climate models. In total, Polarstern will host 600 researchers, four of them from the University of Helsinki. They're analysing the Arctic atmosphere and the processes that take place in it, such as the formation of fine particles. Follow INAR Polar Year for more!