Abstract View
Analysis of Wintertime Alaskan Sea Spray Aerosol Using Single-Particle Mass Spectrometry
JUDY WU, Jun Liu, Jamy Lee, Lucia Upchurch, Patricia Quinn, Son Nghiem, Kerri Pratt, University of Michigan
Abstract Number: 630
Working Group: Remote and Regional Atmospheric Aerosol
Abstract
The Arctic has warmed more rapidly than the global average, and as a result, reduced summertime sea ice is delaying fall sea ice freeze-up in the Arctic and altering the region during the fall-winter transition. Atmospheric aerosol particles can affect climate because 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. Due to logistical challenges in the remote Arctic wilderness, few aerosol measurements have been made during the cold and dark winter, limiting our understanding of aerosol-climate interactions in this season. To better understand Arctic atmospheric processes and to bridge the current seasonal aerosol observation gap, an aerosol time-of-flight mass spectrometer (ATOFMS) was deployed in the November – December 2018 Aerosols during the Polar Utqiaġvik Night (APUN) field campaign near Utqiaġvik, AK to provide real-time size-resolved individual particle chemical composition. Collected during the APUN campaign, the ATOFMS single-particle mass spectra serve as chemical fingerprints to reveal information about particle sources and atmospheric chemical processes. Based on the presence of specific marker ions, sea spray aerosol (SSA) was found to account for a significant fraction of the ~800,000 individual particles chemically analyzed in the study. Both fresh (nascent), non-chloride-depleted SSA particles and partially aged (chloride-depleted and nitrate- and sulfate-enriched) SSA particles were observed. Offline ion chromatography shows agreement with the ATOFMS SSA mass concentrations. We examine the abundance of the nascent SSA in the context of the local open water using satellite-based data. The abundance of fresh SSA particles in this study shows that SSA production continues to be an important local source even during the sea ice freeze up period, which is important to consider as the Arctic is transitioning to larger areas of open ocean in a changing climate.