Abstract View
Mixing State of Secondary Species in Alaskan Arctic Aerosol Using Single-Particle Mass Spectrometry
JUDY WU, Jun Liu, Jamy Lee, Lucia Upchurch, Patricia Quinn, Kerri Pratt, University of Michigan
Abstract Number: 477
Working Group: Remote and Regional Atmospheric Aerosol
Abstract
Atmospheric aerosol particles are complex chemical mixtures that play a significant role in impacting climate and the environment. The distribution of chemical species across the aerosol population (i.e. chemical mixing state) impacts particle properties, including the ability to take up water and to scatter or absorb light. Few measurements exist of the mixing states of aerosol particles in the Arctic, particularly in the fall and winter. To better understand atmospheric processes in the Arctic, the APUN (Aerosols during the Polar Utqiaġvik Night) field campaign during November to December 2018 included deployment of an aerosol time-of-flight mass spectrometer (ATOFMS) to measure the chemical composition of individual particles in Utqiaġvik, AK. These measurements provide information about the sources of aerosol particles and the chemical processes they have undergone in the atmosphere. Based on the presence of specific marker ions, which act as a chemical fingerprint, the particle mass spectra were sorted into groups, including sea spray aerosol (both aged and fresh), organic carbon, biomass burning, and other minor types. For each of these aerosol particle categories, the presence or absence of certain species can shed light on how the aerosol particles were impacted by atmospheric processes such as chemical aging and long-range transport. For instance, numerous aerosol particle spectra contained sulfate or nitrate species, which indicated that chemical aging of the particles occurred. By combining bulk aerosol chemical composition data obtained by the National Oceanic and Atmospheric Administration and single-particle ATOFMS data at Utqiaġvik, the distribution of chemical species measured by the long-term monitoring site across individual particles can be identified and thereby improve the understanding of the atmospheric processes in the Arctic.