In the climatic wind tunnel in Telč, an experiment was conducted in February 2025 to help improve our understanding of rime formation in mountain areas. Due to its properties, rime contains higher concentrations of sulfates, nitrates, and, for example, ammonium ions. For this reason, it can have a significant impact on the eutrophication and acidification of mountain ecosystems. However, rime is currently a neglected component of atmospheric deposition. Previous research has differed in the methodology for quantifying rime, which makes their results difficult to compare.

The experiment conducted in the climatic section of the tunnel aimed not only to compare these different approaches under laboratory conditions, but also to test how accurate these methods are. A new approach to quantifying rime, expected to offer greater accuracy than those used so far, was also tested in the tunnel. During the experiment, suitable conditions for rime formation in mountain areas were successfully simulated in the tunnel. This can be used not only in meteorological research, but also in various engineering fields.

The results of this measurement will assist in the research of the hydrological contribution of rime during the winter period. The preparation, execution, and evaluation of the measurements were carried out by members of the Department of Dynamics and Aerodynamics of the Institute of Theoretical and Applied Mechanics of the Czech Academy of Sciences, in cooperation with employees of the Czech Hydrometeorological Institute and students of the Faculty of Science at Charles University.