New Parameterizations for Neutral and Ion-Induced Sulfuric Acid-Water Particle Formation in Nucleation and Kinetic Regimes

Anni Määttänen (1) , Joonas Merikanto (2) , Henning Henschel (3, 4) , Jonathan Duplissy (3, 5) , Risto Makkonen (3) , Ismael K. Ortega (6) , Hanna Vehkamäki (3)

1 PLANETO - LATMOS
2 FMI - Finnish Meteorological Institute
3 Department of Physics [Helsinki]
4 MIPT - Medical Imaging, Physics and Technology [Oulu]
5 HIP - Helsinki Institute of Physics
6 ONERA - The French Aerospace Lab [Palaiseau]

We have developed new parameterizations of electrically neutral homogeneous and ion-induced sulfuric acid - water particle formation for large ranges of environmental conditions, based on an improved model that has been validated against a particle formation rate data set produced by Cosmics Leaving OUtdoor Droplets (CLOUD) experiments at CERN. The model uses a thermodynamically consistent version of the Classical Nucleation Theory normalized using quantum chemical data. Unlike the earlier parameterizations for H₂SO₄-H₂O nucleation, the model is applicable to extreme dry conditions where the one-component sulfuric acid limit is approached. Parameterizations are presented for the critical cluster sulfuric acid mole fraction, the critical cluster radius, the total number of molecules in the critical cluster, and the particle formation rate. If the critical cluster contains only one sulfuric acid molecule, a simple formula for kinetic particle formation can be used: this threshold has also been parameterized. The parameterization for electrically neutral particle formation is valid for the following ranges: temperatures 165-400 K, sulfuric acid concentrations 10⁴-10¹³ cm⁻³ and relative humidities 0.001-100%. The ion-induced particle formation parameterization is valid for temperatures 195-400 K, sulfuric acid concentrations 10⁴-10¹⁶ cm⁻³ and relative humidities 10⁻⁵-100%. The new parameterizations are thus applicable for the full range of conditions in the Earth's atmosphere relevant for binary sulfuric acid - water particle formation, including both tropospheric and stratospheric conditions. They are also suitable for describing particle formation in the atmosphere of Venus.

Mots clés: particle formation; atmospheres

Mots clés: Acide sulfurique; Nucleation

Domaines: Astrophysique [astro-ph]; Océan, Atmosphère

Anni Määttänen, Joonas Merikanto, Henning Henschel, Jonathan Duplissy, Risto Makkonen, et al.. New Parameterizations for Neutral and Ion-Induced Sulfuric Acid-Water Particle Formation in Nucleation and Kinetic Regimes. Journal of Geophysical Research: Atmospheres, 2018, 123 (2), pp.1269-1296. ⟨10.1002/2017JD027429⟩. ⟨hal-01710882⟩