Aerosol studies in simulated dynamic atmospheres
Abstract
The composition and phase and thereby the optical, hygroscopic, dynamical, and reactive properties of aerosol particles can change in various ways and at all altitudes. A particular important process is the interaction of aerosol particles with water vapour close to or above liquid water or ice saturation. These interactions must be understood and cast in process models in order to assess the role of aerosols in the climate system and in atmospheric chemistry. It is difficult if not impossible to derive, from studies of pure aerosols or from single particle measurements under laboratory conditions, the ensemble-averaged properties of complex aerosol systems under true atmospheric conditions. This is the reason why simulation chamber experiments are needed in aerosol research to bridge the gap between laboratory studies and in situ measurements. AIDA (acronym for Aerosol Interactions and Dynamics in the Atmosphere) is a large (84 m^3) simulation chamber which was designed to study aerosols under dark conditions and on time scales of many hours up to days. Standard aerosol instrumentation is combined with optical in situ and ex situ techniques to characterise the gas- and aerosol phases simultaneously. Guest scientists who participate in the chamber campaigns contribute special instrumentation which is not routinely available. AIDA differs significantly from other simulation chambers of comparable or larger size because it can be evacuated and operated at all tropospheric and stratospheric pressures and temperatures. An outstanding feature of the chamber is the possibility to achieve, for extended time periods, large super-saturations with respect to liquid water, ice or other solid phases by controlled pumping. Powerful process models have been developed to analyse the time evolution of aerosol systems in AIDA simulation runs. Typical applications of the aerosol chamber will be highlighted.
- Publication:
-
EGS - AGU - EUG Joint Assembly
- Pub Date:
- April 2003
- Bibcode:
- 2003EAEJA....14325S