The project aims to advance our knowledge on the sources, spatial distribution, and properties of tropospheric aerosols which are important for climate.
To this end, studies are conducted at sites which are representative for a large area or which are situated within (or downwind of) regions for which a large radiative forcing by anthropogenic aerosols is expected. Both in long-term programs and in intensive measuring campaigns, the chemical, physical, and optical (radiative) properties of the fine (submicrometer) aerosol are investigated. The relative contributions of the important radiatively active aerosol types are determined, the natural and anthropogenic contributions for a number of these aerosol types are distinguished, and the sources, source processes, source regions and transport mechanisms of the aerosols are examined. It is investigated to which extent the fine aerosol mass can be reconstituted on the basis of the measured aerosol types (and thus mass closure can be obtained), and the various aerosol data sets are related to each other and used for model calculations of the optical aerosol properties or of the radiative forcing. As part of the project, novel methods and techniques for aerosol collection, for bulk and individual particle analysis, and for the interpretation and interrelation of the data are developed and implemented.
