Summary: | We proposed to analyze samples for ice nucleating particles (INPs) and microbial composition through a land-based field study, and to eventually simulate observations in an Earth System model. Our overarching hypothesis is that INPs released from thawing permafrost—a hitherto overlooked source of INPs—significantly influence cloud radiative properties in the Arctic. The primary field deployment called ARCSPIN (ARCtic Study of Permafrost Ice Nucleation) was conducted from September 1-17, 2021, within and near Utqiaġvik, Alaska. Permafrost, seasonally thawed active layer, ice wedge, vegetation, water, and aerosol samples were collected. Samples targeted downwind of thermokarst lakes, with some days that collected measurements upwind as well. We also include aerosol filters collected at a fixed site at the Department of Energy Atmospheric Radiation Measurement North Slope of Alaska atmospheric observatory (DOE). Here, we provide the INP-temperature spectra along with 95% confidence interval widths, which follow Agresti and Coull (1998). All samples were processed with the Colorado State University (CSU) Ice Spectrometer (IS), most recently described in Creamean et al. (2022). Agresti, A. and Coull, B. A. (1998). Approximate is better than “exact” for interval estimation of binomial proportions. The American Statistician, 52, 119–126. https://doi.org/10.2307/2685469 Creamean, J.M., Hill, T.C.J., and Hume, C. (2022). Ice Nucleation Spectrometer (INS) Instrument Handbook(DOE/SC-ARM-TR-278, 1846263; p. DOE/SC-ARM-TR-278, 1846263), OSTI.GOV, https://doi.org/10.2172/1846263
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