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Wednesday, October 27, 2021. 3:00 PM. Webinar: Long term trends in aerosol chemical and optical properties measured at the Barrow Atmospheric Baseline Observatory northeast of Utqiaġvik. Trish Quinn, NOAA; Allison Moon and Lucia Upchurch, University of Washington. Sponsored by NOAA. More information here. Register here.

Abstract: Measurements of aerosol chemical composition at the Barrow Atmospheric Baseline Observatory northeast of Utqiavik, Alaska have been conducted since 1997 to assess the impacts of the transport of pollutants from lower latitudes on Arctic atmospheric chemistry and climate. These measurements have been conducted alongside NOAA GML's observations of aerosol optical properties. Here we report on trends in Arctic haze aerosols in terms of composition, optical properties, and transport pathways. Between 1998 and 2013, haze season submicron non-sea salt sulfate and nitrate decreased by 2 and 1% per year, respectively. Supermicron nitrate decreased by 3% per year. Between 1998 and 2020, haze season submicron aerosol light scattering decreased by 1.6% per year and total scattering (particles less than 10 microns in diameter) decreased by 1.1% per year. Aerosol light absorption has also decreased during the haze season. Based on trajectories calculated with HYSPLIT, these decreasing trends appear to be due, at least in part, to a decrease in transport from the European sector to the Arctic. Summertime trends will also be discussed.

Bio(s): TrishQuinn (This email address is being protected from spambots. You need JavaScript enabled to view it.) is the Atmospheric ChemistryGroup (ACG) Lead at NOAA PMEL. The Atmospheric Chemistry Group has been makingshipboard measurements of aerosol chemical, microphysical, optical, andcloud-nucleating properties for over 30 years. The resulting global ocean database can be found at https://saga.pmel.noaa.gov/data/. ACG has also made long-termmeasurements of aerosol composition at NOAA's northern hemisphere monitoringsites including Barrow. These data can be found at https://saga.pmel.noaa.gov/data/stations/