Regional Mountain Conference

The Alpine region plays a central role in the European hydrological cycle, acting not only as a receiver of precipitation but also as an active source of atmospheric moisture through evapotranspiration. The influence of moisture fluxes originating from the Alps extends beyond the supply of precipitation to surrounding lowlands and makes a substantial contribution to local and intra-Alpine precipitation.

While the large-scale origins of precipitation over the Alps have been extensively investigated, particularly through isotopic approaches, this study focuses on resolving the atmospheric connections among different Alpine sub-regions using a moisture-tracking framework. Special attention is given to the spatial distribution of moisture sources and sinks, revealing locally unbalanced water exchanges that give rise to a “moisture-hopping” mechanism and potential pathways for drought propagation. As an illustrative example, we examine the Alpine drought of 2022.

Atmospheric moisture fluxes are quantified using the UTrack atmospheric moisture tracking model, applied both to a climatological mean over the 2008–2017 period and to the 2022 case-study year. Driven by global ERA5 reanalysis, the model allows for a detailed characterization of atmospheric moisture pathways and hydrological interdependencies across the Alpine region.