Josef Dommen

TL;DR: First results from the CLOUD experiment at CERN are presented, finding that atmospherically relevant ammonia mixing ratios of 100 parts per trillion by volume, or less, increase the nucleation rate of sulphuric acid particles more than 100–1,000-fold and ion-induced binary nucleation of H2SO4–H2O can occur in the mid-troposphere but is negligible in the boundary layer.

TL;DR: Results from photooxidation of aromatic compounds in a reaction chamber show that a substantial fraction of the organic aerosol mass is composed of polymers, which results in a lower volatility of this secondaryorganic aerosol and a higher aerosol yield than a model using vapor pressures of individual organic species would predict.

TL;DR: The results show that, in regions of the atmosphere near amine sources, both amines and sulphur dioxide should be considered when assessing the impact of anthropogenic activities on particle formation.

TL;DR: It is shown that organic vapours alone can drive nucleation, and a particle growth model is presented that quantitatively reproduces the measurements and implements a parameterization of the first steps of growth in a global aerosol model that can change substantially in response to concentrations of atmospheric cloud concentration nuclei.

TL;DR: Ion-induced nucleation of pure organic particles constitutes a potentially widespread source of aerosol particles in terrestrial environments with low sulfuric acid pollution.