Upper panel: m∕z spectrum up to m∕z 50. The names of the main ions as predicted by the photochemical model, and their relative abundance is symbolized by the blue dots. Lower panel: m∕z spectrum from m∕z 50 to m∕z 100. Thenames of the main ions as predicted by the photochemical model, and their relative abundance is symbolized by the blue dots. Experimental and numerical data are scaled to m/z 29. The uncertainties on both experimental and numerical predictions are given as boxplots at a 2σ confidence interval.