Diverse springtime variability in ice nucleating particle properties and sources in an Alaskan Arctic oil-field location

The rapid warming of the Arctic has notable implications for the earth's radiative budget, ecological cycle, and mid-latitude weather patterns. Although the Arctic is warming at a faster rate than most regions on earth, key processes that contribute to this warming are not well quantified. Among these processes include the implications of Arctic aerosols, which have the ability to modulate cloud microphysics and subsequent cloud radiative properties through their role as cloud condensation nuclei or ice nucleating particles (INPs). Specifically, the role of INPs is one of the least understood with regard to Arctic aerosol-cloud interactions. The ability of aerosols to serve as INPs is dependent on their size, composition, and number concentration, which varies largely depending on their sources. Previous studies have suggested that combustion-derived particles from the Prudhoe Bay oil-fields in Northern Alaska play an important role in modulating cloud microphysics in the region, thus having air quality and climatic implications. Daily aerosol samples were collected from 11 Mar to 31 May 2017 at Oliktok Point, a coastal site in Northern Alaska in the Prudhoe Bay oil-fields, using a four-stage time- and size-resolved impactor during a study called INPOP (Ice Nucleating Particles at Oliktok Point). The size-resolved sampling allowed a wide range of aerosols to be evaluated. Preliminary results suggest that March, April, and May were each exposed to variable INP populations due to influences from industrial, marine, and terrestrial sources. Changes in INP concentrations and freezing temperatures can be explained by local and regional meteorology and air mass transport from such sources. Results such as these can be used to improve model simulations of aerosol-cloud interactions in the Arctic in mixed-source locations such as Prudhoe Bay.