Chemical nucleation theory for various humidities and pollutants

Abstract

The Flood–Neumann–Döring–Reiss–Doyle theory gives a strong dependence of the nucleation rate on the humidity (for r.h. < 100%) and shows that under atmospheric condition H₂SO₄, but not HNO₃, SO₂, or NH₃, contributes directly to the aerosol nucleation without pre-existing nuclei. Typically, 10⁹ H₂SO₄ molecules per cm³ are enough to form droplets of aqueous sulphuric acid solutions.