American Geophysical Union Become an AGU Member
Subscribe to AGU Journals		 AGU Home AGU Publications

Read Full Article (file size: 2387130 bytes)    Cited by

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 113, D12209, doi:10.1029/2007JD009327, 2008

How biogenic terpenes govern the correlation between sulfuric acid concentrations and new particle formation

B. Bonn

Department of Physical Sciences, Helsinki University, Helsinki, Finland


M. Kulmala

Department of Physical Sciences, Helsinki University, Helsinki, Finland


I. Riipinen

Department of Physical Sciences, Helsinki University, Helsinki, Finland


S.-L. Sihto

Department of Physical Sciences, Helsinki University, Helsinki, Finland


T. M. Ruuskanen

Department of Physical Sciences, Helsinki University, Helsinki, Finland


Abstract

New particle formation has been observed to take place all around the world. However, because of the inability to determine the chemical composition of the smallest clusters or particles, indirect tools such as the correlation between nucleation rate and measured sulfuric acid concentrations have been used to infer the nucleation mechanism. In this study we describe the observed correlation with gaseous sulfuric acid concentrations by interactions of sesquiterpene oxidation products with sulfuric acid. Two formation pathways of nucleation initiating molecules are considered. The interaction of sulfuric acid with organic sulfates, which are formed from stabilized Criegee intermediates (sCIs, formed from sesquiterpenes), can be used to explain the observed squared relationship between particle formation rate and ambient sulfuric acid concentrations. The corresponding linear dependence is explained with the participation of secondary ozonides, which are formed from sCIs and aldehydes. Both pathways are negatively affected by increasing water vapor concentration as observed in recent studies. In order to check the assumptions made we apply the derived nucleation coefficients to measurements of the BACCI/QUEST IV campaign made during spring 2005 in Hyytiälä, Finland. A reasonable agreement between the measurement data and the predicted nucleation rates is found, giving support for the presented nucleation description.

Received 28 August 2007; accepted 2 April 2008; published 25 June 2008.

Keywords: nucleation rate; sulphuric acid; terpenes.

Index Terms: 0305 Atmospheric Composition and Structure: Aerosols and particles (0345, 4801, 4906); 0315 Atmospheric Composition and Structure: Biosphere/atmosphere interactions (0426, 1610); 0317 Atmospheric Composition and Structure: Chemical kinetic and photochemical properties.

Read Full Article (file size: 2387130 bytes)    Cited by

Citation: Bonn, B., M. Kulmala, I. Riipinen, S.-L. Sihto, and T. M. Ruuskanen (2008), How biogenic terpenes govern the correlation between sulfuric acid concentrations and new particle formation, J. Geophys. Res., 113, D12209, doi:10.1029/2007JD009327.