Number concentration of ice nucleating particles N(INP) in the Arctic were derived from filter samples collected at Villum Research Station (VRS, Northern Greenland) during the course of two years, from July 2018 to September 2020. Each filter aimed at sampling for 3.5 days, and in total, 181 samples were retrieved for this study. Filter analysis was done with two well proven INP analysis techniques, ultimately resulting in a spectrum of N(INP) for each filter. We also included a heat treatment of the samples (1 hour at 90°C, or at 85°C for a few exceptions, due to instrumental issues). With this, one can determine the fraction of proteinaceous INP, which are of biological origin. For each filter sample, we here provide the temperature dependent measured frozen fractions (f_ice) of each filter from both instruments LINA (Leipzig Ice Nucleation Array) and INDA (Ice Nucleation Droplet Array) included in separate files (e.g. INDA2_20180716_1 for INDA; LINA_20190923_1 for LINA). Most filters underwent thermal treatment and therefore the f_ice of the treated samples is also provided in separate files (e.g. INDA2_20200622_heated_90_1h_1). For each filter sample, values of N(INP) spectra from LINA and INDA were interpolated to values at 0.1K intervals, and then the two spectra were merged. Details on this procedure can be found in Sze et al. (2023).
The here presented data includes one spectrum of INP concentrations for each sample (covering the temperature range from -4.5°C down to -30.4°C), merged from a LINA and an INDA measurement. (Hint: Due to the measurement procedure, separate spectra generally are only available over a more narrow temperature range, so empty fields are left blank by intention.) Also, additional details for each sample are available, such as start and end date of the sampling and the sampled air volume. For the basic f_ice data, refer to the related data (doi:10.1594/PANGAEA.953839).