The interaction of N₂O₅ with mineral dust: aerosol flow tube and Knudsen reactor studies

C. Wagner (1) , F. Hanisch (1) , N. Holmes (1) , H. de Coninck (1) , G. Schuster (1) , J. N. Crowley (1)

1 MPIC - Max-Planck-Institut für Chemie

The interaction of mineral dust with N₂O₅ was investigated using both airborne mineral aerosol (using an aerosol flow reactor with variable relative humidity) and bulk samples (using a Knudsen reactor at zero humidity). Both authentic (Saharan, SDCV) and synthetic dust samples (Arizona test dust, ATD and calcite, CaCO₃) were used to derive reactive uptake coefficients (?). The aerosol experiments (Saharan dust only) indicated efficient uptake, with e.g. a value of ?(SDCV)=(1.3±0.2)×10^?2 obtained at zero relative humidity. The values of ? obtained for bulk substrates in the Knudsen reactor studies are upper limits due to assumptions of available surface area, but were in reasonable agreement with the AFT measurements, with: ?(SDCV)=(3.7±1.2)×10^?2, ?(ATD)=(2.2±0.8)×10^?2 and ?(CaCO₃=(5±2)×10^?2. The errors quoted are statistical only. The results are compared to literature values and assessed in terms of their impact on atmospheric N₂O_5.

Domaines: Océan, Atmosphère

C. Wagner, F. Hanisch, N. Holmes, H. de Coninck, G. Schuster, et al.. The interaction of N₂O₅ with mineral dust: aerosol flow tube and Knudsen reactor studies. Atmospheric Chemistry and Physics, 2008, 8 (1), pp.91-109. ⟨hal-00296409⟩