Ubiquity and dominance of oxygenated species in organic aerosols in anthropogenically‐influenced Northern Hemisphere midlatitudes

TLDR

HOA originates mainly from fossil fuel combustion and other primary sources, yet global models often omit secondary organic aerosol, potentially biasing OA magnitude and properties. Organic aerosol data from 37 field campaigns were deconvolved into hydrocarbon‑like OA and several oxygenated OA components. OOA dominates OA across urban to remote sites (64–95%) and, as shown in a rural case study, its concentrations exceed HOA, implying that secondary organic aerosol—not HOA oxidation—is the primary source of OOA.

Abstract

Organic aerosol (OA) data acquired by the Aerosol Mass Spectrometer (AMS) in 37 field campaigns were deconvolved into hydrocarbon‐like OA (HOA) and several types of oxygenated OA (OOA) components. HOA has been linked to primary combustion emissions (mainly from fossil fuel) and other primary sources such as meat cooking. OOA is ubiquitous in various atmospheric environments, on average accounting for 64%, 83% and 95% of the total OA in urban, urban downwind, and rural/remote sites, respectively. A case study analysis of a rural site shows that the OOA concentration is much greater than the advected HOA, indicating that HOA oxidation is not an important source of OOA, and that OOA increases are mainly due to SOA. Most global models lack an explicit representation of SOA which may lead to significant biases in the magnitude, spatial and temporal distributions of OA, and in aerosol hygroscopic properties.