Volatility of secondary organic aerosol during OH radical induced ageing

The aim of this study was to investigate oxidation of SOA formed from ozonolysis of <i>α</i>-pinene and limonene by hydroxyl radicals. This paper focuses on changes of particle volatility, using a Volatility Tandem DMA (VTDMA) set-up, in order to explain and elucidate the mechanism behind atmospheric ageing of the organic aerosol. The experiments were conducted at the AIDA chamber facility of Karlsruhe Institute of Technology (KIT) in Karlsruhe and at the SAPHIR chamber of Forchungzentrum Jülich (FZJ) in Jülich. A fresh SOA was produced from ozonolysis of <i>α</i>-pinene or limonene and then aged by enhanced OH exposure. As an OH radical source in…