Chemistry of Sulfur Dioxide and Dimethyl Sulfide in the Tropical Marine Boundary Layer

Drexel University, Philadelphia PA

Investigators

Abstract

There is currently major uncertainty regarding the oxidation pathways of dimethyl sulfide (DMS) within the tropical marine boundary layer and in the relative strength of biogenic sources to the global sulfur budget. The investigators extend upon their previous work on the atmospheric chemistry of atmospheric sulfur compounds by developing state-of-the-art fast-response Atmospheric Pressure Ionization Mass Spectrometer (APIMS) instruments to experimentally determine all the terms in the chemical budgets of DMS and sulfur dioxide (SO2). Important DMS oxidative loss pathways produce dimethyl sulfoxide (DMSO) and dimethyl sulfone (DMSO2). The investigators will use APIMS technology to measure these species, modifying additional APIMS instruments to this purpose and evaluating them through laboratory studies. The measurements these instruments will ultimately provide ambient atmospheric data valuable for chemical model development and verification, as well as producing a more observationally constrained budget for climate-relevant sulfur gases in the marine boundary layer. Broader impacts of the research include new tools to characterize atmospheric sulfur cycling and through support for a postdoctoral scholar, research training experience for an early-career geoscientist. With support from this award the investigators will assemble a research team through external investigator collaborations to plan and execute a comprehensive tropical marine boundary layer sulfur biogeochemical cycling experiment to take place in the near future.