ATMOCHEM - Biological aerosol particles in the atmosphere and their impact on clouds (BIOCLOUDS)

• Antragsteller: Professor Dr. Thomas Koop; Dr. Ottmar Möhler
• Fachliche Zuordnung: Physik und Chemie der Atmosphäre
• Förderung: Förderung von 2008 bis 2014
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 82797955

Aerosol particles play a key role in atmospheric sciences and climate, as they are essential for cloud formation. A subgroup are aerosol particles of biological origin (ABO) which include plant debris, pollen or living organisms like bacteria, fungi and yeasts. Recent measurements on the Puy de Dome station have identified in cloud water the presence of bacteria, yeasts and fungi. One can speculate that, in a warmer and more humid climate, more bacteria will find viable conditions in the atmosphere and, thus, become even more abundant in aerosols and clouds.It is known from previous studies that such ABO particles have the potential to act as cloud condensation nuclei (CCN) and ice nuclei (IN) and thereby influence the formation and evolution of clouds, in particular the initiation of precipitation. However, new laboratory and cloud modelling studies are needed to quantify the microphysical role of ABO in clouds and thereby also their indirect effect on climate. The microphysical properties of both pristine ABO and those aged in the atmosphere by heterogeneous chemistry and cloud processes are important and need to be quantified, in particular for those ABO species found in clouds, snow, and precipitation water.The proposed project BIOCLOUDS aims at investigating and quantifying the role of ABO particles in tropospheric clouds. It is a contribution to topic area 1 “Tropospheric Aerosols and Clouds”, subtopics 2 (The biogenic aerosol) and 4 (Cloud processing) within the call for proposals. The four project partners and two associated partners will combine their expertise in microbiology, aerosol-cloud microphysics, meteorology, and cloud modelling in order to (1) identify relevant species in cloud and precipitation water and, for comparison, in the aerosol outside clouds, (2) extract and culture relevant samples for laboratory investigations of CCN and IN properties, and, (3) make use of the new experimental results as input to cloud models in order to improve the formulation of microphysical processes for ABO in models and to more accurately assess the potential importance of these processes for cloud evolution. Species of interest for the suggested project are bacteria, yeasts, fungi, pollen and plant debris.

• DFG-Verfahren: Sachbeihilfen
• Internationaler Bezug: Frankreich
• Beteiligte Personen: Dr. Anne-Marie Delort; Professorin Dr. Andrea Ilse Floßmann