Secondary organic aerosol reduced by mixture of atmospheric vapours
Journal article, 2019

Secondary organic aerosol contributes to the atmospheric particle burden with implications for air quality and climate. Biogenic volatile organic compounds such as terpenoids emitted from plants are important secondary organic aerosol precursors with isoprene dominating the emissions of biogenic volatile organic compounds globally. However, the particle mass from isoprene oxidation is generally modest compared to that of other terpenoids. Here we show that isoprene, carbon monoxide and methane can each suppress the instantaneous mass and the overall mass yield derived from monoterpenes in mixtures of atmospheric vapours. We find that isoprene ‘scavenges’ hydroxyl radicals, preventing their reaction with monoterpenes, and the resulting isoprene peroxy radicals scavenge highly oxygenated monoterpene products. These effects reduce the yield of low-volatility products that would otherwise form secondary organic aerosol. Global model calculations indicate that oxidant and product scavenging can operate effectively in the real atmosphere. Thus highly reactive compounds (such as isoprene) that produce a modest amount of aerosol are not necessarily net producers of secondary organic particle mass and their oxidation in mixtures of atmospheric vapours can suppress both particle number and mass of secondary organic aerosol. We suggest that formation mechanisms of secondary organic aerosol in the atmosphere need to be considered more realistically, accounting for mechanistic interactions between the products of oxidizing precursor molecules (as is recognized to be necessary when modelling ozone production).

Author

G. McFiggans

Th. F. Mentel

J. Wildt

Iida Pullinen

Sungah Kang

Einhard Kleist

Sebastian Schmitt

Monika Springer

R. Tillmann

Cheng Wu

Defeng Zhao

Mattias Hallquist

University of Gothenburg, Department of Chemistry

Michael Le Breton

Åsa M. Hallquist

David Simpson

Chalmers, Space, Earth and Environment, Microwave and Optical Remote Sensing, Global Environmental Measurements and Modelling

Robert Bergström

University of Gothenburg, Department of Chemistry

SMHI

Chalmers, Space, Earth and Environment, Microwave and Optical Remote Sensing

M. E. Jenkin

Mikael Ehn

Joel A. Thornton

M. Rami Alfarra

Thomas J. Bannan

C. J. Percival

Michael Priestley

University of Gothenburg, Department of Chemistry

D. Topping

A. Kiendler-Scharr

Nature

0028-0836 (ISSN) 1476-4687 (eISSN)

Vol. 565 7741 587-593

ModElling the Global Earth system (MERGE)

Lund University, 2018-01-01 -- 2019-12-31.

Atmospheric oxidation of stress induced emissions from vegetation - its role for aerosol formation

Formas, 2016-01-01 -- 2018-12-31.

Subject Categories

Meteorology and Atmospheric Sciences

Roots

Basic sciences

DOI

10.1038/s41586-018-0871-y

More information

Latest update

2/3/2019 5