Research interests:

Secondary Organic Aerosols (SOA)

Objectives: Quantify secondary organic aerosol (SOA) formation and the impact of parameters such as relative humidity (RH) and reaction temperature. Investigate mechanisms and corresponding product distributions of selected reaction systems at low temperatures (down to 243K). Characterise and establish temperature dependence on changes in properties of SOA:s, for use and implementation in modelling tools, e.g. volatility and hygroscopic properties. Generally, any studies on particles are important to resolve their impact on human health and climate change.

Description: Most of the previous work on SOA has been conducted at room temperature or higher and the description of the temperature dependence on SOA is derived from theoretical work or based on few studies. This project focuses on low temperature experiments. The reason is two-folded: 1) To apply to ambient atmospheric conditions and usage in ambient aerosol models, where there is an obvious need for low temperature information. 2) Using temperature dependence gives insight into the actual mechanisms for SOA formation and will elucidate if existing models include the proper description of the SOA formation. The experiments are conducted at low concentrations (few ppb converted). Important properties, such as volatility, particle size/mass and chemical composition will be monitored for the selected experimental conditions. In addition to experiments in the newly built temperature controlled facility in Göteborg, collaborative experiments will continue in the smog chamber facilities in Karlsruhe and Jülich.

Selected publications:

Jonsson ÅM, Hallquist M, Ljungström E, (2006) "Impact of Humidity on the Ozone Initiated Oxidation of limonene, 3-carene, and a-pinene", Environ. Sci. Technol. 40, 188-194

Janhäll S, Jonsson ÅM, Molnar P, Svensson EA, Hallquist M, (2004) "Size Resolved Traffic Emission Factors of Submicrometer Particles", Atmospheric Environment 38 (26): 4331-4340