Such discrepancies have likely consequences for predictions of NOx availability and ozone production, and the sensitivity of these quantities to aerosol particle loadings. Citation: Bertram, T. H., J. A. Thornton, T. P. Riedel, A. M. Middlebrook, R. Bahreini, T. S. Bates, P. K. Quinn, and D. J. Coffman (2009), Direct observations of N2O5 reactivity on ambient aerosol particles, Geophys.