Hirschi et al. (2026) Recent summer soil moisture drying in Switzerland based on measurements from the SwissSMEX network

Identification

• Journal: Earth system science data
• Year: 2026
• Date: 2026-07-13
• Authors: Martin Hirschi, Dominik Michel, Dominik L. Schumacher, Wolfgang Preimesberger, Sonia Isabelle Seneviratne
• DOI: 10.5194/essd-18-4855-2026

Research Groups

• ETH Zurich, Institute for Atmospheric and Climate Science (IACS)
• TU Wien, Department of Geodesy and Geoinformation

Short Summary

This paper presents a curated set of in situ soil moisture time series from the SwissSMEX network on the Swiss Plateau, covering 2010-2025. The data show a non-significant trend towards drying in summer soil moisture.

Objective

• Investigate the temporal evolution and drying trends in mean summer (June-August) and summer-half-year (April-September) soil moisture anomalies using the SwissSMEX network.

Study Configuration

• Spatial Scale: Local to regional scale, covering the Swiss Plateau.
• Temporal Scale: 2010-2025, with a focus on recent trends.

Methodology and Data

• Models used: ERA5-Land (a land component of the ERA5 reanalysis) and C3S SM PASSIVE (a satellite-based soil moisture product).
• Data sources: In situ measurements from the SwissSMEX network, as well as gridded products from ERA5-Land and C3S SM PASSIVE.

Main Results

• The SwissSMEX data show a non-significant trend towards drying in summer soil moisture, with a Theil-Sen trend slope of -1.4 mm/yr.
• The agreement between the different station combinations regarding the temporal evolution of the Swiss Plateau median soil moisture is evident in the inter-annual variations of the summer and summer-half-year soil moisture anomalies.

Contributions

• This study provides a comprehensive set of in situ soil moisture time series from the SwissSMEX network, which can be used to investigate drying trends on the Swiss Plateau.
• The results show that the recent evolution of SwissSMEX aligns well with the longer-term evolution of soil moisture from ERA5-Land and C3S SM PASSIVE.

Funding

• This research was funded by the ETH Zurich and the TU Wien.

Citation

@article{Hirschi2026Recent,
  author = {Hirschi, Martin and Michel, Dominik and Schumacher, Dominik L. and Preimesberger, Wolfgang and Seneviratne, Sonia Isabelle},
  title = {Recent summer soil moisture drying in Switzerland based on measurements from the SwissSMEX network},
  journal = {Earth system science data},
  year = {2026},
  doi = {10.5194/essd-18-4855-2026},
  url = {https://doi.org/10.5194/essd-18-4855-2026}
}