The ACES (Aerosol Coupling in the Earth System) project was an integrated research programme that aims to reduce uncertainties in our fundamental understanding of the formation of BSOA (Biogenic Secondary Organic Aerosol) and the subsequent impact on atmospheric composition, through coordinated chamber studies, field studies, process model development, and application of atmospheric models of chemistry and transport to assess coupling and feedbacks in the Earth system.

The ACES project is part of the APPRAISE (Aerosol Properties, PRocesses And Influences on the Earth's climate) thematic programme of the Natural Environment Research Council (NERC). Its aim is to understand and quantify how aerosols affect the Earth's radiation budget, by scattering and/or absorbing radiation, influence clouds, and hence indirectly affect climate and the hydrological cycle, and contribute to feedback processes between land, the biosphere and climate.

The ACES project is a consortium project consisting of researchers from The Centre for Environmental Policy at Imperial College London, The School of GeoSciences at The University of Edinburgh, The Department of Chemistry at The University of Leicester, The Centre for Atmospheric Science at The University of Manchester, The Department of Chemistry at The University of York, Centre for Ecology and Hydrology (CEH), and The Department of Environmental Science at The University of Lancaster.

Data for the project has been collected by the University of Manchester Sonic Anemometer 1, Scanning Mobility Particle Sizer, Condensation Particle Counter, GRIMM Optical Particle Counter in the tropical forest of Borneo, and the Aerosol Chamber in the Manchester University Laboratory.