GEOPHYSICAL RESEARCH LETTERS, VOL. 30, NO. 10, 1526, doi:10.1029/2003GL017084, 2003

Nucleation rate of particles in the lower atmosphere: Estimated time needed to reach pseudo-steady state and sensitivity to H2SO4 gas concentration

Fangqun Yu

Atmospheric Sciences Research Center, State University of New York,
Albany, New York, USA

Abstract

[1]   Using a kinetic model, we estimate the time-needed (t0) to establish a pseudo-steady state nucleation when sulfuric acid concentration ([H2SO4]) suddenly increases to a certain fixed level. We find that t0 is roughly inversely proportional to [H2SO4]. The assumption of instantaneously achieved pseudo-steady state concentration of critical clusters, on which the classical nucleation theories are based, is no longer valid when t0 is longer than the time period that [H2SO4] can be treated as constant. Under the lower marine atmospheric conditions considered in this study, the nucleation rate predicted by ion-mediated nucleation theory is very sensitive to [H2SO4] when [H2SO4] is low (<~7 × 106/cm3) but such a sensitivity reduces significantly as [H2SO4] increases, which is quite different from that predicted with classical binary and ternary homogeneous nucleation theories.

Received 8 February 2003; revised 10 April 2003; accepted 16 April 2003; published 24 May 2003.

Index Terms: 0305 Atmospheric Composition and Structure: Aerosols and particles (0345, 4801); 0365 Atmospheric Composition and Structure: Troposphere—composition and chemistry.


AGU

Citation: Yu, F., Nucleation rate of particles in the lower atmosphere: Estimated time needed to reach pseudo-steady state and sensitivity to H2SO4 gas concentration, Geophys. Res. Lett., 30(10), 1526, doi:10.1029/2003GL017084, 2003.