2 TorniJaKyvetti mBackground The Centre of Excellence in Atmospheric Science – From Molecular and Biological processes to the Global Climate (ATM) originates from early-1980’s, when scientists from Department of Physics and Department of Forest Ecology at the University of Helsinki created a multidisciplinary team and started to unravel questions related to biosphere-atmosphere interactions.

Objective Our main scientific objective is to quantify the feedbacks between the atmospheric processes and changing functioning of biosphere in changing climate. In order to do this, we will 1) find out and quantify the main climatic feedbacks and forcing mechanisms related to aerosols, clouds, precipitation, biosphere-atmosphere and cryosphere-atmosphere interactions, 2) develop, refine and utilize the newest measurement techniques and modeling tools scaling from quantum chemistry to global Earth System Observations and Models, 3) create a deep and quantitative understanding on the role of atmospheric clusters and aerosol particles in local and global biogeochemical cycles of water, carbon, sulfur and nitrogen and their linkages to the atmospheric chemistry, and 4) integrate the results in the context of regional and global scale Earth system understanding

Research Our multidisciplinary research team includes 235 scientists working in the fields of physics, chemistry, biology and meteorology at the Universities of Helsinki and Eastern Finland (Kuopio), and at the Finnish Meteorological Institute. Our work is based on a network of field stations producing extensive long-term data on atmospheric properties and ecological mass fluxes in different types of environments and regions, including Arctic, boreal and tropical ecosystems, and on focused experiments and modeling aimed at understanding the observed patterns. We have been awarded with the Academy of Finland CoE status three times since 2002 and the Nordic CoE status in 2003 and 2010.





Figure. The two feedback loops associated with the COBACC (COntinental Biosphere-Aerosol-Cloud-Climate) feedback. BVOC=biogenic volatile organic compounds, SOA=secondary organic aerosol, CS=the condensation sink, Atot=total aerosol surface area, Vtot=total aerosol volume, CCN=cloud condensation nuclei, CDNC=cloud droplet number concentration, and GPP=Gross Primary Productivity, which is a measure of ecosystem-scale photosynthesis.