The chamber at CERN where measurements were conducted (Image: Hanna Manninen)
A new mechanism was discovered in a study published in the journal Nature, which suggests that nitric acid, sulphuric acid and ammonia can together form aerosol particles and ice nuclei much more efficiently than previously understood. This mechanism is thought to be particularly significant in the cold environments.
More information at https://www.helsinki.fi/en/news/mathematics-and-science/nitric-acid-may-influence-formation-aerosol-particles-upper-troposphere