Currently, there is a critical deficiency in Arctic field data regarding the abundance and composition of atmospheric ice-nucleating particles (INP) at temperatures above -15 °C. This project will fill this gap by experimentally elucidating sources, abundance, and physicochemical properties of INP. State-of-the-art representations of high-temperature INPs from the Atlantic sector of the Arctic will advance the atmospheric modeling knowledge of the ice nucleation processes and its role in the Earth’s energy balance. The project also aims to provide robust and well-characterized INP measurements. The measurements from this project, in collaboration with the existing transnational Arctic research community knowledge, will improve the understanding of the nature of aerosols, dramatically improving the understanding of ice formation processes currently very poorly represented in climate models.