Ground-level ice nucleating particle abundance on the North Slope of Alaska during Fall-Winter 2021

Atmospheric ice-nucleating particles (INPs) are an important subset of aerosol particles that promote the heterogeneous formation of ice crystals under ice supersaturated conditions. In the Arctic, INPs contribute to partitioning between ice and liquid water in mixed-phase clouds, influencing their albedo and climate forcing. Furthermore, because INPs can catalyze precipitation and function as cloud-destroying agents, the increase in INPs may result in accelerated positive radiative feedback. However, the abundance and source of Arctic INPs are not yet well understood. This study examined how profound atmospheric dynamics and extreme meteorological conditions coinciding with low-pressure systems introduce INP anomalies on the North Slope of Alaska (NSA). A Portable Ice Nucleation Experiment (PINE) chamber, which simulates adiabatic expansion cooling, was used to monitor, and measure INP abundance with ≈12-min time resolution at Barrow Atmospheric Baseline Observatory (71.32° N, 156.61° W). The INP abundance is reported as a function of freezing temperature between the approximate -15 °C and -30 °C range and collected in November-December 2021. The offline measurements of the same period are found using the West Texas Cryogenic Refrigerator Applied to Freezing Test (WT-CRAFT) at temperatures between 0 °C and -25 °C. Measured INP concentrations at overlapping temperatures of both instruments are then compared. Besides the discussion of general INP abundance in the NSA region, the influence of atmospheric low-pressure systems, as well as geopotential iii height anomalies, on the ground-based INP abundance (averaged for 6-hour) is discussed in this work. The influence of heating on multi-seasonal INP abundance is also discussed. A potential linkage was observed between INP concentration and the newly developed climate index Aleutian Low Beaufort Sea Anticyclone (ALBSA). Finally, the current international protocols for ambient aerosols, as well as further need in the international legitimate framework for the aerosol-cloud-climate interactions, are investigated and discussed.