Reactive iodine plays a key role in determining the oxidation capacity, or cleansing capacity, of the atmosphere in addition to being implicated in the formation of new particles in the marine boundary layer. The postulation that heterogeneous cycling of reactive iodine on aerosols may significantly influence the lifetime of ozone in the troposphere not only remains poorly understood but also heretofore has never been observed or quantified in the field. Here, we report direct ambient observations of hypoiodous acid (HOI) and heterogeneous recycling of interhalogen product species (i.e., iodine monochloride [ICl] and iodine monobromide [IBr]) in a midlatitude coastal environment. Significant levels of ICl and IBr with mean daily maxima of 4.3 and 3.0 parts per trillion by volume (1-min average), respectively, have been observed throughout the campaign. We show that the heterogeneous reaction of HOI on marine aerosol and subsequent production of iodine interhalogens are much faster than previously thought. These results indicate that the fast formation of iodine interhalogens, together with their rapid photolysis, results in more efficient recycling of atomic iodine than currently considered in models. Photolysis of the observed ICl and IBr leads to a 32% increase in the daytime average of atomic iodine production rate, thereby enhancing the average daytime iodine-catalyzed ozone loss rate by 10 to 20%. Our findings provide direct field evidence that the autocatalytic mechanism of iodine release from marine aerosol is important in the atmosphere and can have significant impacts on atmospheric oxidation capacity.

除了与海洋边界层中新颗粒的形成有关外，活性碘在确定大气的氧化能力或净化能力方面也起着关键作用。气溶胶上活性碘的异质循环可能会显着影响对流层中臭氧的寿命的假设不仅仍然知之甚少，而且迄今为止从未在该领域观察或量化。在这里，我们报告了在中纬度沿海环境中对次碘酸 (HOI) 和卤间产物物种（即一氯化碘 [ICl] 和一溴化碘 [IBr]）的异质循环的直接环境观察。ICl 和 IBr 的显着水平，按体积计算，平均每日最大值分别为 4.3 和 3.0 ppm（1 分钟平均值），在整个竞选过程中都观察到了。我们表明，HOI 对海洋气溶胶的非均相反应以及随后产生的碘间卤素比以前认为的要快得多。这些结果表明，碘间卤素的快速形成以及它们的快速光解作用导致原子碘的回收比目前模型中考虑的更有效。观察到的 ICl 和 IBr 的光解导致日间平均原子碘生成率增加 32%，从而将日间碘催化臭氧平均损失率提高 10% 至 20%。我们的研究结果提供了直接的现场证据，表明海洋气溶胶释放碘的自催化机制在大气中很重要，并且可能对大气氧化能力产生重大影响。我们表明，HOI 对海洋气溶胶的非均相反应以及随后产生的碘间卤素比以前认为的要快得多。这些结果表明，碘间卤素的快速形成以及它们的快速光解作用导致原子碘的回收比目前模型中考虑的更有效。观察到的 ICl 和 IBr 的光解导致日间平均原子碘生成率增加 32%，从而将日间碘催化臭氧平均损失率提高 10% 至 20%。我们的研究结果提供了直接的现场证据，表明海洋气溶胶释放碘的自催化机制在大气中很重要，并且可能对大气氧化能力产生重大影响。我们表明，HOI 对海洋气溶胶的非均相反应以及随后产生的碘间卤素比以前认为的要快得多。这些结果表明，碘间卤素的快速形成以及它们的快速光解作用导致原子碘的回收比目前模型中考虑的更有效。观察到的 ICl 和 IBr 的光解导致日间平均原子碘生成率增加 32%，从而将日间碘催化臭氧平均损失率提高 10% 至 20%。我们的研究结果提供了直接的现场证据，表明海洋气溶胶释放碘的自催化机制在大气中很重要，并且可能对大气氧化能力产生重大影响。