The Aerosol Coupling in the Earth System (ACES) project was one of three strategic, interlinking consortium projects run under the NERC Aerosol Properties, PRocesses And InfluenceS on the Earth’s Climate (APPRAISE) programme. ACES comprised two main components, a field deployment to the Borneo Rainforest and a targeted series of atmospheric simulation chamber experiments at the University of Manchester, with our work focusing on the latter. The primary objectives of ACES were to improve our understanding of the fundamental properties, composition and formation mechanisms of Biogenic Secondary Organic Aerosol (BSOA), which play an important role in global climate. Our simulation chamber experiments, focusing on the biogenic VOCs, isoprene, beta-caryophyllene, alpha-pinene, limonene and myrcene, were instrumental in elucidating key gas-phase oxidation mechanisms and were used to construct and refine subsets of the Master Chemical Mechanism. Key linkages between certain gas-phase precursor oxidation products and aerosol composition were also identified and important findings regarding species-specific BSOA properties were made. Mesocosm experiments were also conducted comparing and contrasting temperate and tropical tree species, with findings detailing the different VOC matrices and their interactions with and impacts upon the particle-phase.
