Volatile organic compound ratios as probes of halogen atom chemistry in the Arctic

[摘要] Volatile organic compound concentration ratios can be used as indicators ofhalogen chemistry that occurs during ozone depletion events in the Arcticduring spring. Here we use a combination of modeling and measurements of[acetone]/[propanal] as an indicator of bromine chemistry, and[isobutane]/[n-butane] and [methyl ethyl ketone]/[n-butane] are used tostudy the extent of chlorine chemistry during four ozone depletion eventsduring the Polar Sunrise Experiment of 1995. Using a 0-D photochemistrymodel in which the input of halogen atoms is controlled and varied, theapproximate ratio of [Br]/[Cl] can be estimated for each ozone depletionevent. It is concluded that there must be an additional source of propanal(likely from the snowpack) to correctly simulate the VOC chemistry of theArctic, and further evidence that the ratio of Br atoms to Cl atoms can vary greatly duringozone depletion events is presented.

[学科分类] 大气科学