Local and long-range transported sources of natural aerosols in southern Greenlandic fjord systems

The Arctic is warming up to four times faster than the global average with fragile fjord ecosystems in the relatively warm Southern Greenland being especially sensitive to changes across various facets of the environment. With longer and warmer summer melt periods leading to increased glacial melt with marine and land-terminating glaciers slowly receding, the potential of sediments from newly exposed glacial outwash plains to be aerosolized increases. At the same time biological productivity in the ocean is changing. Hence, the composition and sources of atmospheric aerosols responsible for the formation of clouds in this region are evolving and we expect this to influence both the cloud condensation nuclei (CCN) and Ice Nucleating Particle (INP) populations. Given the complex terrain and mixture of ice, ocean and land in fjord systems, the dispersion of aerosols and gases originating at the surface is subject to lower atmosphere stability and dynamics before they can reach cloud level. In this presentation, we will show results from a comprehensive and extensive field campaign in the Kullajeq province of Southern Greenland in June-August 2023. We will present vertical aerosol size distributions, particle number concentrations and absorption measurements taken using a tethered balloon in addition to complementary ground based online aerosol measurements. Two key sources of aerosols will be discussed: near-daily local new particle formation (NPF), and long-range transported Canadian wildfire plumes. We will explore the following questions: Are aerosols from fjords and increased biological productivity the source of the frequent NPF observed in Narsaq, and how do aerosols from distant sources such as Canadian biomass burning effect the aerosol population in Southern Greenland?