Preimesberger et al. (2026) C3S SM PASSIVE Daily Gap-filled Root-Zone Soil Moisture from merged multi-satellite observations

Identification

• Journal: TU Wien Research Data
• Year: 2026
• Date: 2026-01-30
• Authors: W. Preimesberger, Johanna Lems, Martin Hirschi, Wouter Arnoud Dorigo
• DOI: 10.48436/9j8ad-z2q11

Research Groups

• TU Wien
• ETH Zurich

Short Summary

This dataset provides global daily gap-filled root-zone soil moisture estimates at 0.25° resolution for 1991-2025, derived from merged passive microwave satellite observations and processed using univariate interpolation and an exponential filter method.

Objective

• To generate a consistent, global, daily, and gap-free long-term climate data record of root-zone soil moisture at multiple depths using merged passive microwave satellite observations.

Study Configuration

• Spatial Scale: Global coverage, 0.25° (~25 km) horizontal grid resolution.
• Temporal Scale: Daily estimates from January 1991 to October 2025.

Methodology and Data

• Models used: Univariate interpolation algorithm (for gap-filling surface observations), exponential filter-based method (for assessing root-zone soil moisture).
• Data sources: Merged observations from 14 passive microwave satellite sensors (C3S PASSIVE record), Copernicus Climate Change Service (C3S) Satellite Soil Moisture product, ESA CCI Soil Moisture method.

Main Results

• The dataset provides global daily root-zone soil moisture (RZSM) estimates in volumetric units (m³/m³) for four depth layers: 0-0.1 m, 0.1-0.4 m, 0.4-1.0 m, and 1.0-2.0 m.
• Each RZSM estimate is accompanied by corresponding uncertainty estimates (m³/m³).
• The data is gap-free and covers a period of 35 years.

Contributions

• This dataset offers a unique, long-term (35-year), global, daily, and gap-free record of root-zone soil moisture, crucial for climate variability and change studies, hydrological modeling, and drought applications.
• It builds upon and extends existing C3S and ESA CCI Soil Moisture products with enhanced gap-filling techniques and a robust exponential filter method for root-zone estimation, providing data at multiple depths with uncertainty quantification.

Funding

• Copernicus Climate Change Service (C3S)
• ESA Climate Change Initiative (CCI) Soil Moisture program

Citation

@article{Preimesberger2026C3S,
  author = {Preimesberger, W. and Lems, Johanna and Hirschi, Martin and Dorigo, Wouter Arnoud},
  title = {C3S SM PASSIVE Daily Gap-filled Root-Zone Soil Moisture from merged multi-satellite observations},
  journal = {TU Wien Research Data},
  year = {2026},
  doi = {10.48436/9j8ad-z2q11},
  url = {https://doi.org/10.48436/9j8ad-z2q11}
}