Atmospheric composition and cloud formation are important drivers of the Arctic surface energy budget. Airborne microbiology plays an important yet largely unquantified role in atmospheric composition, cloud formation and thereby radiative forcing. There are two principal classes of compounds in which the biosphere impacts atmospheric composition, i.e. through primary biological aerosol particles (PBAPs) and biogenic volatile organic compounds (BVOCs). PBAP are microorganisms (bacteria, viruses, spores, cells) and exopolymeric substances exuded by microorganisms. They are expelled into the atmosphere from the sea surface micro layer, open leads, melt ponds and snow on sea ice. PBAP can also be transported from terrestrial sources. Once in the atmosphere, they can act as ice nucleating particles (INP), which are critical for the ice formation in clouds at warm temperatures (i.e. higher than -15°C). BVOCs are gases that are emitted for example from the ocean (e.g., from phytoplankton), boreal forests or tundra. They are oxidized in the atmosphere and then condense onto particles. These particles are good cloud condensation nuclei (CCN). CCN are needed to form cloud droplets. Together INP and CCN determine the impacts of clouds on the surface energy budget, so for example how much sea ice will melt. The Atmosphere research cluster aims to study how important biology is for the surface energy budget.
Research Cluster PI
- Julia Schmale, EPFL, Switzerland
Research Cluster Collaborators
- Lionel Favre, EPFL, Switzerland
- Henrik Helmig, EPFL, Switzerland
- Michel Flores, Weizmann Institute of Science, Israel
- Ilan Koren, Weizmann Institute of Science, Israel
- Assaf Vardi, Weizmann Institute of Science, Israel
- Kathy Law, LATMOS, CNRS, Paris, France
- Jean-Christoph Raut, LATMOS, CNRS, Paris, France
- François Ravetta, LATMOS, CNRS, Paris, France
- Julien Delanoe, LATMOS, CNRS, Paris, France