Naturally produced organohalogens; Atmospheric simulation experiments on halogen activation in aerosol smog chamber facilities with sea salt and secondary organic aerosol (HALOSOA)

Zusammenfassung(Deutsch)大陆和海洋气团的混合导致了活化的卤素与来自土壤和类腐殖质的腐殖质化合物(HULIS)的相互作用，HULIS是最近才被发现的一种普遍存在的气溶胶成分--众所周知的主要由天然碳氢化合物气态转化为颗粒的次生有机气溶胶(SOA)。海雾中的卤化物通过光化学作用，包括臭氧、OH自由基和其他光氧化剂被氧化成卤化化合物，其中氮(NO、NO2、N3、N2O5)和酸的活性氧化物起着决定性的作用。得到的活化卤素(X、X2、XY、XO、HOX、XNO、XNO2、XONO2和卤素X、Y=氯、溴和碘)可以形成有机卤素化合物，其中一些是气态的，一些留在颗粒中。本研究的目的是在气溶胶烟雾室实验中模拟这种环境状况(从盐湖和火山羽流通过海洋边界层到北极条件)，并采用多种技术进行研究，通过特定指示剂的时间分布和直接、微分光学和腔增强吸收光谱(DOAS和CEAS)通过自由基时钟观察活化的卤素，并通过特定技术检测气相和颗粒相中的卤化有机物，如GC-ECD、GC-HID、GC-MS、TPP-MS、直接气溶胶-MS、离子色谱和高效液相-DAD(包括ICR-FTMS、来自外部合作者和活动嘉宾的AM和CIM)。氯、溴和碘对这些地球化学循环的贡献是通过各种支持实验来确定的，更不用说要外推到对流层边界层的室内实验中观测的强制性模型计算了。

Zusammenfassung (deutsch)Mixing of continental and marine air masses causes an interaction of activated halogens with humic compounds from soil and humic-like substances (HULIS), detected only recently as an ubiquitous aerosol constituent – the well-known secondary organic aerosol (SOA) from gas-to-particle conversion of mainly natural hydrocarbons. The halides from sea-spray are oxidized to halogenating compounds by photochemical, heterogeneous interactions involving ozone, OH radicals and other photooxidants, where reactive oxides of nitrogen (NO, NO2, NO3, N2O5) and acids play a decisive role. The resulting activated halogens (X, X2, XY, XO, HOX, XNO, XNO2 XONO2 with halogens X, Y = Cl, Br and I) may form organohalogen compounds, some of which are gaseous and some of which remain in the particles. The goal of the present study is to simulate this environmental situation (covering the full range from salt lakes and volcanic plumes via marine boundary layer to arctic conditions) in aerosol smog chamber experiments and to investigate it by a large variety of techniques, observing the activated halogens by the radical clock from time profiles of specific indicators and by direct, differential optical and cavity enhanced absorption spectroscopy (DOAS and CEAS), and detecting halogenated organics in gas and particle phase by specific techniques, such as GC-ECD, GC-HID, GC-MS, TPP-MS, direct aerosol-MS, ion chromatography and HPLC-DAD (including ICR-FTMS, AMS and CIMS from external collaborators and guests in campaigns). The contributions of Cl, Br and I to these geochemical cycles are settled by various supporting experiments, not to mention mandatory model calculations of the observations in the chamber experiments to be extrapolated to the boundary layer of the troposphere.