Alternative pathway for atmospheric particles growth
Open Access
- 18 April 2012
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 109 (18), 6840-6844
- https://doi.org/10.1073/pnas.1120593109
Abstract
Credible climate change predictions require reliable fundamental scientific knowledge of the underlying processes. Despite extensive observational data accumulated to date, atmospheric aerosols still pose key uncertainties in the understanding of Earth’s radiative balance due to direct interaction with radiation and because they modify clouds’ properties. Specifically, major gaps exist in the understanding of the physicochemical pathways that lead to aerosol growth in the atmosphere and to changes in their properties while in the atmosphere. Traditionally, the driving forces for particle growth are attributed to condensation of low vapor pressure species following atmospheric oxidation of volatile compounds by gaseous oxidants. The current study presents experimental evidence of an unaccounted-for new photoinduced pathway for particle growth. We show that heterogeneous reactions activated by light can lead to fast uptake of noncondensable Volatile Organic Compounds (VOCs) at the surface of particles when only traces of a photosensitizer are present in the seed aerosol. Under such conditions, size and mass increase; changes in the chemical composition of the aerosol are also observed upon exposure to volatile organic compounds such as terpenes and near-UV irradiation. Experimentally determined growth rate values match field observations, suggesting that this photochemical process can provide a new, unaccounted-for pathway for atmospheric particle growth and should be considered by models.Keywords
This publication has 48 references indexed in Scilit:
- Nucleation and Growth of Nanoparticles in the AtmosphereChemical Reviews, 2011
- Heterogeneous light-induced ozone processing on the organic coatings in the atmosphereAtmospheric Environment, 2009
- Ubiquity and dominance of oxygenated species in organic aerosols in anthropogenically‐influenced Northern Hemisphere midlatitudesGeophysical Research Letters, 2007
- COPASI—a COmplex PAthway SImulatorBioinformatics, 2006
- Aromatic Carbonyl Compounds as Aqueous-Phase Photochemical Sources of Hydrogen Peroxide in Acidic Sulfate Aerosols, Fogs, and Clouds. 1. Non-Phenolic Methoxybenzaldehydes and Methoxyacetophenones with Reductants (Phenols)Environmental Science & Technology, 1996
- The photochemistry of aqueous nitrate ion revisitedJournal of Photochemistry and Photobiology A: Chemistry, 1996
- Reactive species produced on irradiation at 365 nm of aqueous solutions of humic acidsJournal of Photochemistry and Photobiology A: Chemistry, 1996
- Benz[a]anthracene photodegradation in the presence of known organic constituents of atmospheric aerosolsEnvironmental Science & Technology, 1995
- Transformation Kinetics of Phenols in Water: Photosensitization by Dissolved Natural Organic Material and Aromatic KetonesEnvironmental Science & Technology, 1995
- A global model of natural volatile organic compound emissionsJournal of Geophysical Research: Solid Earth, 1995