Objective
To study the different classes of organic compounds present in the fine-mode aerosol and to relate the organic composition of aerosol particles to the ability of the particles themselves to act as cloud condensation
Previous experiments in different areas of the world evidenced that a bimodal hygroscopic behaviour of the
submicron aerosol population exists, with two groups of particles, generally defined as "morehygroscopic" and
"less-hygroscopic". While the more-hygroscopic particles usually grow by nucleation to form cloud droplets,
the less-hygroscopic ones remain in the interstitial air between the droplets. There are evidences that
hydrophobic organic substances represent a relevant fraction of the less-hygroscopic particles.
The project will develop an analytical protocol to separate the major classes of stable organic components of
the aerosol particles, and to identify the more important compounds for each class. Such protocol will first be
tested to study the organic components of submicron aerosol samples from three different European sites,
representative of different pollution situations and different aerosol types:
*S. Pietro Capofiume (polluted area in the Po Valley, Italy); *K-puszta (rural continental area in the Great Hungarian Plain);
*Aspvretem (a background coastal site in Central Sweden characterized, depending on airflow patterns,
by both marine and continental air).
In a second phase of the project, it is proposed to carry out a field campaign in the Po Valley (Italy) during the
fog season, to study, by means of the analytical methods elaborated during the first phase, the partitioning of
the organic components of the atmospheric aerosol particles between fog droplets and interstitial air. The
physical and chemical properties of aerosol particles in the Po Valley and their relation to fog droplet formation
have extensively been studied during a previous large experiment in 1989, although the issue of the organic
component of the aerosol was not addressed at that time. These previous studies have shown that the fog
droplets are almost solely grown on the more-hygroscopic particles and that the interstitial particles are mostly
the less-hygroscopic ones. This means that the fog can be used as a "natural separator" of particles of different
hygroscopic properties. By concurrent sampling of fog droplets and interstitial particles, and successive chemical
analysis, there will be the possibility to investigate the role of the stable organic compounds of the two separate
populations of particles in determining their hygroscopic behaviour.
This project addresses basic questions concerning the chemical nature of CCN and is expected to provide new
insight into the multiphase processes leading to cloud formation. The issue of the organic constituents of
atmospheric fine particles is important both for cloud chemistry and climate research.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
- natural scienceschemical sciencesorganic chemistry
- natural sciencesearth and related environmental sciencesenvironmental sciencespollution
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Call for proposal
Data not availableFunding Scheme
CSC - Cost-sharing contractsCoordinator
40129 Bologna
Italy