Item: INVESTIGATING THE RELATIONSHIP BETWEEN ICE PARTICLES IN CLOUDS AND PRECIPITATION PARTICLES DURING SNOWFALL EVENTS: A CASE STUDY AT SONNBlick OBSERVATORY, AUSTRIA
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Title: INVESTIGATING THE RELATIONSHIP BETWEEN ICE PARTICLES IN CLOUDS AND PRECIPITATION PARTICLES DURING SNOWFALL EVENTS: A CASE STUDY AT SONNBlick OBSERVATORY, AUSTRIA
Proceedings: Proceedings, International Snow Science Workshop, Whistler, BC, Canada, 2026
Authors:
- Veronika Krieger [ GeoSphere Austria – Avalanche Warning Service Salzburg, Salzburg, Austria ]
- Julia Burkart [ GeoSphere Austria – Sonnblick Observatory, Salzburg, Austria ]
- Christian Maier [ GeoSphere Austria – Sonnblick Observatory, Salzburg, Austria ]
- Thomas Bachleitner [ GeoSphere Austria – Sonnblick Observatory, Salzburg, Austria ]
- Gerhard Schauer [ GeoSphere Austria – Sonnblick Observatory, Salzburg, Austria ]
Date: 2026-09-28
Abstract: The Sonnblick Observatory - located at 3,116 m above sea level in the Austrian Alps - provides a unique environment for studying cloud microphysics under in-situ conditions. Operated by the national meteorological service GeoSphere Austria, the observatory is equipped with a wide range of instruments, related to the atmosphere, biosphere and cryosphere. The site combines continuous environmental measurements with year-round human observations of snowfall and snowpack properties. This combination gives us the opportunity to analyze the transformation of ice crystals from their formation through to snowfall. Snow crystals exhibit a wide range of morphologies depending on temperature and supersaturation. Based on these parameters, the Nakaya diagram offers a long-established classification system of crystal shapes. However, as snow and ice are sensitive to changes in temperature, humidity, evaporation and wind, the structure of the precipitation particles is expected to evolve within the cloud, during their descent through the atmosphere, and after deposition on the snow surface. Because of this complexity, the relationship between ice crystals forming within clouds and snowflakes reaching the surface remains insufficiently understood. At Sonnblick Observatory small ice crystals (0.5-200μm) within clouds are documented using a measurement device that takes holographic images (SwisensPoleno Jupiter). Meteorological conditions at the observatory are constantly monitored by standardized instruments (WMO Standard). In addition, the shape of the fallen snowflakes is determined and classified through human observation using a snow grid card. As part of this study, an automatic image classification system was implemented and tested on the holographic images. This made it possible to analyze data across various meteorological conditions and to investigate both how these conditions influence snow crystal shape and how crystals evolve between their formation in clouds and their deposition as snow flake to the surface. Improved understanding of snow crystal evolution can further help us to better comprehend the effects on snowpack formation and its subsequent transformation.
Object ID: ISSW2026_P4.40.pdf
DOI: https://doi.org/10.15788/1790099355
Language of Article: English
Presenter(s): Veronika Krieger
Keywords: ice crystal formation, crystal growth, holographic imaging, Nakaya diagram, in-cloud particles
Page Number(s): 1761 - 1768
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