The abundance of ground-level atmospheric ice-nucleating particles and aerosol properties in the North Slope of Alaska

We present one of the first long-duration ambient ice-nucleating particle (INP) data for the Arctic, two years of INP concentrations (nINP) measured continuously at the Barrow Atmospheric Baseline Observatory (BRW) in North Slope of Alaska. The BRW site is located at 71.32° N, 156.61° W and about 6 km northeast of the nearest residential area, Utqiaġvik, AK. The field measurements were initiated in October 2021 and lasted until May 2024 as part of the multi-year remote observation campaign, called the Examining INP at NSA (ExINP-NSA; https://www.arm.gov/research/campaigns/nsa2021exinpnsa last seen on June 16th, 2024). A portable ice nucleation experiment chamber (PINE-03), which simulates adiabatic expansion cooling, was used to directly monitor the ground-level ambient INP abundance with an approximately 12-minute time resolution from October 2021 to December 2023. We report PINE-03-measured nINP data over a wide range of heterogeneous freezing temperatures from -16 °C to -31 °C. Complementary aerosol and meteorological data analyses were performed to assess the correlation between ambient INP propensity, air mass source region, and meteorological variability in NSA.A total of 8 datasets is provided (the metadata and data matrices are separated). An individual method-oriented data abstract is available in metadata for each output sub-folder. All Python codes used for processing input data and generating output data are paired with the readme files and archived in folders. The output data is produced by including all dataset (denoted All) and/or processing a subset of flagged dataset (namely Flagged or Contaminated) and other non-flagged screened dataset (denoted Non-flagged or Screened/Clean). The data flagging algorithm using wind direction at the observatory is a simple yet useful way of identifying contamination from the town. It is worth noting that we also flag the data based on wind speed and number concentration, and data mentor edits. The algorithm we use is described in this paper (Sheridan et al., 2016). This method is consistent across the NOAA observatories and varies only by definition for the clean air sector. NOAA provides flagging information of aerosol data for every minute. NOAA’s aerosol data flagging was synchronized to the PINE-03 data acquisition interval.Reference: Sheridan, P., Andrews, E., Schmeisser, L., Vasel, B., and Ogren, J.: Aerosol Measurements at South Pole: Climatology and Impact of Local Contamination, Aerosol Air Qual. Res., 16, 855–872, https://doi.org/10.4209/aaqr.2015.05.0358, 2016.