Isoprene nitrates drive new particle formation in Amazon's upper troposphere.

ABSTRACT: New particle formation (NPF) in the tropical upper troposphere is a globally important source of atmospheric aerosols^1-4. It is known to occur over the Amazon basin, but the nucleation mechanism and chemical precursors have yet to be identified². Here we present comprehensive in situ aircraft measurements showing that extremely low-volatile oxidation products of isoprene, particularly certain organonitrates, drive NPF in the Amazonian upper troposphere. The organonitrates originate from OH-initiated oxidation of isoprene from forest emissions in the presence of nitrogen oxides from lightning. Nucleation bursts start about 2 h after sunrise in the outflow of nocturnal deep convection, producing high aerosol concentrations of more than 50,000 particles cm^-

SUBMITTER: Curtius J 

PROVIDER: S-EPMC11618076 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature