Formation of nanoparticles of blue haze enhanced by anthropogenic pollution
- 20 October 2009
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 106 (42), 17650-17654
- https://doi.org/10.1073/pnas.0910125106
Abstract
The molecular processes leading to formation of nanoparticles of blue haze over forested areas are highly complex and not fully understood. We show that the interaction between biogenic organic acids and sulfuric acid enhances nucleation and initial growth of those nanoparticles. With one cis-pinonic acid and three to five sulfuric acid molecules in the critical nucleus, the hydrophobic organic acid part enhances the stability and growth on the hydrophilic sulfuric acid counterpart. Dimers or heterodimers of biogenic organic acids alone are unfavorable for new particle formation and growth because of their hydrophobicity. Condensation of low-volatility organic acids is hindered on nano-sized particles, whereas ammonia contributes negligibly to particle growth in the size range of 3-30 nm. The results suggest that initial growth from the critical nucleus to the detectable size of 2-3 nm most likely occurs by condensation of sulfuric acid and water, implying that anthropogenic sulfur emissions (mainly from power plants) strongly influence formation of terrestrial biogenic particles and exert larger direct and indirect climate forcing than previously recognized.Keywords
This publication has 35 references indexed in Scilit:
- Laboratory studies of H2SO4/H2O binary homogeneous nucleation from the SO2+OH reaction: evaluation of the experimental setup and preliminary resultsAtmospheric Chemistry and Physics, 2008
- Variability in morphology, hygroscopicity, and optical properties of soot aerosols during atmospheric processingProceedings of the National Academy of Sciences, 2008
- Laboratory‐measured nucleation rates of sulfuric acid and water binary homogeneous nucleation from the SO2 + OH reactionGeophysical Research Letters, 2008
- Heterogeneous chemistry of octanal and 2, 4‐hexadienal with sulfuric acidGeophysical Research Letters, 2005
- Ozonolysis of α-pinene and β-pinene: Kinetics and mechanismThe Journal of Chemical Physics, 2005
- Particle Formation by Ion Nucleation in the Upper Troposphere and Lower StratosphereScience, 2003
- Molecular composition of organic aerosols formed in the α‐pinene/O3 reaction: Implications for new particle formation processesJournal of Geophysical Research: Solid Earth, 1998
- Recent progress in understanding particle nucleation and growthPhilosophical Transactions Of The Royal Society B-Biological Sciences, 1997
- A global model of natural volatile organic compound emissionsJournal of Geophysical Research: Solid Earth, 1995
- Physical chemistry of the sulfuric acid/water binary system at low temperatures: stratospheric implicationsThe Journal of Physical Chemistry, 1993