Atmospheric aerosol sources and composition during summer at two Alaskan Arctic coastal sites

Description

To investigate natural versus anthropogenic and local versus distal contributions to atmospheric aerosol in the summertime Arctic, field campaigns are ongoing at two Department of Energy Atmospheric Radiation Measurement climate research facilities since 2015. Barrow, AK, is located on the northern most point of the United States; the site is 7.4 km north of the village of Barrow (population 4,581). Oliktok Point, AK, is 300 km south east of Barrow in a region of intense petroleum development. The proximity of the two sites allows for a finer spatial analysis of Arctic aerosol composition, size and source contributions with contrasting local sources. Total suspended particulate (TSP) and fine particulate samples were collected and filters were analyzed for inorganic ions, organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), and radiocarbon (14C) abundance. Preliminary results indicate a potential connection between temperature and carbon concentration/biogenic sources in the summer. Summer results will be discussed in context of historical inorganic and BC trends on the NSA. This work builds on a previous 2012-13 ARM campaign that focused on annual trends in sources of EC at Barrow, but also included OC and WSOC measurements. In addition, single-particle chemical composition (by electron microscopy and single-particle mass spectrometry) is used to characterize the local combustion plumes as well as the regional background aerosol.