Collaborative Research: Multiphase Halogen Chemistry in the Atlantic Marine Boundary Layer

该合作项目旨在重新回顾先前启动的现场实验，以进一步表征某些（Cl, Br）卤素物种和自由基在大小分离气溶胶和海洋边界层（MBL）平衡气流中的化学浓度和转化。这些大气化学研究将在全球大西洋样带（不来梅港-开普敦）上由德国科考船R/V Polarstern与一组德国和英国调查人员合作进行，他们参与了一套辅助气相（光谱，气相色谱等）和气溶胶表征测量。这些测量将与多相光化学模拟工作相辅相成。本研究的科学目标是描述和解释沿全球经向巡航样带的多相卤素循环，将提供并通过更广泛的一系列测量来了解卤素激活，卤素物种diel循环，卤素气相气溶胶分配，气溶胶pH变化以及对对流层臭氧和硫（IV）物种的寿命和循环的影响的相关推断。目前对MBL中多相卤素转化反应的作用及其对全球海洋大气非均质大气化学过程的潜在影响的理解，由于缺乏可靠的关键卤素物种的现场浓度测量而受到阻碍。该项目将增强我们对自然卤素循环化学与人为干扰的重要性的理解。该项目将加强机构间和国际层面的研究和教育伙伴关系。

This collaborative project seeks to revisit previously initiated field experiments in order to further characterize the chemical concentrations and transformations of certain (Cl, Br) halogen species and radicals in both size segregated aerosols and equilibrated gas streams of the marine boundary layer (MBL). These atmospheric chemical studies will be carried out on a global Atlantic Ocean transect (Bremerhaven - Capetown) aboard the German research vessel R/V Polarstern, conjointly with a team of German and British investigators engaged making a suite of ancillary gas-phase (spectroscopic, GC etc), and aerosol characterization measurements. These measurements will be complemented with multiphase photochemical modeling efforts. The scientific goal of this study, to characterize and interpret multiphase halogen cycling along a global meridional cruise transect, will provide and be informed by the broader suite of measurements enabling insight into halogen activation, halogen species diel cycling, halogen gas-phase aerosol partitioning, aerosol pH variability together with related inferences on the impacts on lifetimes and cycling of tropospheric ozone and sulfur (IV) species. Current understanding of the role of multiphasic halogen transformation reactions in the MBL and their potential impact on heterogeneous atmospheric chemical processes in the global marine atmosphere is hampered by a lack of reliable field concentration measurements of key halogen species. The project will enhance our understanding of the importance of natural halogen cycle chemistry in relation to anthropogenic perturbation. The project will enhance research and education partnerships at both inter-institutional and international levels.