Aerosol particles that can aid the formation of ice crystals in clouds are known as ice nucleating particles (INPs). These particles play a critical role in Arctic cloud formation and regional climate. However, it remains challenging for global climate models (GCMs) to well represent Arctic INPs. To understand the biases in the GCMs, we compare simulated results from a GCM with long-term meteorological, aerosol, and INP measurements at one surface station in Ny-Ålesund, Svalbard. We find that the simulated aerosol properties are biased from the observations within one order of magnitude, due to uncertainties in modeling physical and chemical aerosol processes. Using soil samples collected from Ny-Ålesund, we derived a new fit that relates local HLD with INP concentrations. This fit shows strong ice nucleating ability at warm temperatures, indicating the presence of organic matter in local HLD. Incorporating the new fit for local HLD INPs along with parameterizations representing INPs from other terrestrial and marine sources, our model reproduces measured INP concentrations reasonably well. Our comparison highlights the importance of local HLD to the Arctic INP population. Our findings emphasize the need for long-term Arctic measurements and better representation of HLD in GCMs to improve the understanding in Arctic INP properties and their role in Arctic cloud formation.
