Articles | Volume 16, issue 20
Atmos. Chem. Phys., 16, 13231–13249, 2016
Atmos. Chem. Phys., 16, 13231–13249, 2016

Research article 27 Oct 2016

Research article | 27 Oct 2016

Estimating N2O5 uptake coefficients using ambient measurements of NO3, N2O5, ClNO2 and particle-phase nitrate

Gavin J. Phillips1, Jim Thieser1, Mingjin Tang1, Nicolas Sobanski1, Gerhard Schuster1, Johannes Fachinger2, Frank Drewnick2, Stephan Borrmann2, Heinz Bingemer3, Jos Lelieveld1, and John N. Crowley1 Gavin J. Phillips et al.
  • 1Department of Atmospheric Chemistry, Max Planck Institute for Chemistry, Mainz, Germany
  • 2Particle Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
  • 3Institute for Atmospheric and Environmental Sciences, Goethe University, Frankfurt, Germany

Abstract. We present an estimation of the uptake coefficient (γ) and yield of nitryl chloride (ClNO2) (f) for the heterogeneous processing of dinitrogen pentoxide (N2O5) using simultaneous measurements of particle and trace gas composition at a semi-rural, non-coastal, mountain site in the summer of 2011. The yield of ClNO2 varied between (0.035 ± 0.027) and (1.38 ± 0.60) with a campaign average of (0.49 ± 0.35). The large variability in f reflects the highly variable chloride content of particles at the site. Uptake coefficients were also highly variable with minimum, maximum and average γ values of 0.004, 0.11 and 0.028 ± 0.029, respectively, with no significant correlation with particle composition, but a weak dependence on relative humidity. The uptake coefficients obtained are compared to existing parameterizations based on laboratory datasets and with other values obtained by analysis of field data.

Short summary
We use trace gas measurements (N2O5, ClNO2, NO3) and particle properties (surface area, nitrate content etc.) to derive uptake coefficients (the probability of removal from the gas-phase on a per-collision basis) for the interaction of N2O5 with ambient aerosol and also the efficiency of formation of ClNO2. The uptake coefficients show high variability but are reasonably well captured by parameterisations based on laboratory measurements.
Final-revised paper