Laboratory-measured nucleation rates of sulfuric acid and water binary homogeneous nucleation from the SO2 + OH reaction
Abstract
We have measured H2SO4-H2O nucleation rates (J) at atmospheric pressure, 288 K and 10-55 % relative humidity (RH). H2SO4 was produced from the SO2 + OH -> HSO3 reaction and was measured with a chemical ionization mass spectrometer (CIMS). The CIMS-measured [H2SO4] that is required to produce the unit J ranged from 107-108 cm-3, but if wall loss is taken into account the threshold [H2SO4] was at the 108-109 cm-3 range, much higher than the atmospheric conditions. The measured J was proportional to [H2SO4] with the second to tenth powers and proportional to RH with the eleventh to fifteenth powers. The measured aerosol sizes were proportional to log RH, showing a weak dependence of aerosol growth on RH. But the RH effects were more pronounced at higher [H2SO4], indicating that RH is more important for aerosol growth in the H2SO4 rich environment.
- Publication:
-
Geophysical Research Letters
- Pub Date:
- June 2008
- DOI:
- 10.1029/2008GL033387
- Bibcode:
- 2008GeoRL..3511801B
- Keywords:
-
- Atmospheric Composition and Structure: Aerosols and particles (0345;
- 4801;
- 4906);
- Atmospheric Composition and Structure: Chemical kinetic and photochemical properties;
- Atmospheric Composition and Structure: Cloud physics and chemistry;
- Atmospheric Composition and Structure: Troposphere: composition and chemistry;
- Atmospheric Composition and Structure: Troposphere: constituent transport and chemistry