The Transregional Collaborative Research Centre TR 172 (AC)³ and the University of Helsinki organized a joint winter school on Arctic amplification at the Hyytiälä Forestry Field Station in Finland. The field station is located about 200 km north of Helsinki in a boreal forest. This remote place served as the perfect place to learn about state-of-the-art observations of the atmosphere and biosphere.

Our daily program consisted of lectures in the morning by scientists from Europe and the U.S. and a combination of group work and field excursions in the afternoon. The lectures covered all research topics of (AC)³: surface energy budget over sea ice and open ocean, cloud microphysics, aerosols, ocean and atmosphere remote sensing, climate feedback mechanisms, Arctic water cycle, atmospheric rivers, and polar-midlatitude linkages. A highlight was an excursion to the meteorological towers that observe for example the formation of new aerosol particles and the deposition of CO₂ by the forest (see photos below).