Measurements of blowing snow particle size distribution using an open-path optical snow particle counter in Ny-Ålesund during winter 2025

During the Intensive Observation Period for Water in all its phases (IOP4H2O) an open-path optical Snow Particle Counter (SPC, Sato et al. 1993, Ranjithkumar et al. 2025) measured particle size distributions of snow particles close to the snow surface in Ny-Ålesund from 31st January until 3rd March 2025. Due to a freely rotating wind-vane, the SPC detects snow particles that are transported horizontally by the wind, but can also include falling snow crystals. The detected particles, with diameters ranging from 36 to 500 µm, are sorted into 65 size bins. The snow mass flux (given in kg m⁻² s⁻¹) is calculated by assuming spherical particles with an ice density of 917 kg m⁻³ that pass through an observation area of 50 mm². The SPC was co-located with the Video In Situ Snowfall Sensor (VISSS, Maahn et al. 2024) and mounted around 10 cm above the snow surface, to achieve measurements of the saltation layer. The height of the SPC was regularly adjusted to the changing snow depth. During the first three weeks unrealistically low values were measured for individual size bins because of an error of the SPC (marked by the quality flag) that was solved on 19th February. During this period the size distribution and snow mass flux are inaccurate, but still serve as qualitative measures of blowing snow intensity. This data was collected to investigate sublimation of blowing snow in Ny-Ålesund. It might also be relevant for research on snow accumulation and distribution and to evaluate gauges of solid precipitation.