ROOOH: a missing piece of the puzzle for OH measurements in low-NO environments?

摘要: Abstract. Field campaigns have been carried out with the FAGE (fluorescence assay by gas expansion) technique in remote biogenic environments last decade to quantify situ concentrations of OH, main oxidant the atmosphere. These data revealed OH radicals up to a factor 10 higher than predicted by models, whereby disagreement increases decreasing NO concentration. This was interpreted as a major lack our understanding chemistry VOCs (volatile organic compounds), particularly isoprene, which are dominant pristine conditions. But interferences these measurements unknown origin have also discovered for some instruments: using pre-injector, all ambient is removed fast reaction before entering cell, and any remaining signal can be attributed an interference. is now systematically used measurements, allowing reliable quantification ambient along due to interference OH. However, disagreement between modelled measured high OH earlier field well the now-quantifiable background still not understood. We present this paper compelling idea that this interference, thus disagreement between model measurement campaigns, might at least partially unexpected decomposition new class molecule, ROOOH, within instruments. based on experiments, obtained set-up University Lille, supported a modelling study. Even though occurrence interference will be highly dependent design conditions different FAGE instruments, including ROOOH atmospheric models reflect a missing piece puzzle clean atmospheres.