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

University Of Virginia Main Campus, Charlottesville VA

Investigators

Abstract

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.