Trends In Arctic Aerosol Sources And Chemical Composition At Utqiagvik (Barrow), Alaska

Abstract:

Arctic haze is the seasonal maximum of atmospheric aerosols in the arctic in the late winter and early spring. Aerosol impacts on clouds, radiative forcing, and the Earth’s energy budget are among the greatest uncertainties in climate sensitivity modeling. Additionally, air pollution from lower latitudes and deposition onto snowpack reduces ice-surface albedo which may contribute to accelerated warming in the arctic in a process known as arctic amplification. Consequently, understanding the sources, transport, and composition of aerosols in the arctic is imperative. NOAA has been measuring atmospheric chemical composition at Barrow, Alaska since 1997, though meteorological research at Barrow spans back to the nineteenth century. Chemical components of arctic haze include particulate matter from air pollution, dust, organic matter, and sea salt. Size-segregated filter samples collect large volumes of air at Barrow which are weighed, extracted, and then characterized via ion chromatography and X-ray fluorescence spectroscopy. The HYSPLIT model was used to evaluate trends in local and long-range transport of aerosols from 1997-2020. Trajectory analysis has revealed changes in short-range and long-range atmospheric transport to Barrow in recent years. This study analyzes the sources and seasonality of aerosols at Barrow and determines their correspondence with processes within and outside the Arctic.