EC-01. Retrieval of perchlorate and other new aerosol species from mass spectra measured by Aerodyne aerosol mass spectrometers (AMS) during previous aircraft missions around the globe
In order to better understand the role of aerosols in the atmosphere, existing 3D chemical transport models (CTMs) need to be constantly evaluated with new observations. To that end, measurements of aerosol chemical composition with broad spatial coverage are required. Online measurements of aerosol physical properties are more common, but measurements of chemical composition outside of the Northern Hemisphere boundary layer are rare, which leads to large uncertainties in modeling and interpretation of satellite aerosol observations. For species that are not observable from satellites, data from either ground platforms or fast-response instruments onboard aircraft platforms are required for model evaluation. In this work, we revisit the aerosol mass spectrometer (AMS) datasets acquired from previous aircraft field campaigns (e.g., ATom and KORUS-AQ), for quantification of aerosol species that are newly retrievable by these instruments. These aerosol species include perchlorate, iodine/bromine species, methanesulfonic acid (MSA), and isoprene-epoxydiols-drived secondary organic aerosol (IEPOX-SOA). Exposure to perchlorate affects human’s endocrine system. While the atmospheric sources of perchlorate are highly uncertain, snow and ice core records suggest that chlorofluorocarbons (CFCs) might be important precursors for the photochemical production of perchlorate in the stratosphere. In addition, each of these other new species play an important role in the atmospheric process of halogen, sulfur, nitrogen, and isoprene, (respectively) thus our new dataset puts important constraints on the budgets, cycling and gas-particle partitioning of these species. We are currently working on the retrieval, the analysis of the spatiotemporal distribution of these species, and the comparison to current CTM simulations (i.e., perchlorate in the lower stratosphere).