Soil Moisture Data Subset from the Community Land Model Version 5 (CLM5) for the Soil Parameter Model Intercomparison Project (SP-MIP) over the Continental United States (CONUS), 1980-2010

<h3>Description</h3> <div> <p>This dataset contains a subset of soil moisture data simulated by the Community Land Model Version 5 (CLM5), developed by the National Center for Atmospheric Research (NCAR), as part of the Soil Parameter Model Intercomparison Project (SP-MIP). The data covers the Continental United States (CONUS) region from 1980 to 2010 and is derived from seven experimental runs designed to assess the influence of soil hydraulic parameters on soil moisture variability in land surface models (LSMs). The subset focuses on the root zone soil moisture (0–1 m depth) at a spatial resolution of 0.5° × 0.5°.</p> <p>The dataset originates from the SP-MIP framework, coordinated by Lukas Gudmundsson and Matthias Cuntz, which was established following the GEWEX-SoilWat workshop in Leipzig (Gundmundsson and Cuntz, 2017). SP-MIP aimed to quantify the variability in LSM outputs due to differences in soil parameters and model structures, using the Global Soil Wetness Project Phase 3 (GSWP3) forcing data. This specific subset was extracted and analyzed in the study titled "Soil Parameterization in Land Surface Models Drives Large Discrepancies in Soil Moisture Predictions Across Hydrologically Complex Regions of the Contiguous United States" (Silwimba et al., 2025, preprint available at EGUsphere: <a href="https://doi.org/10.5194/egusphere-2025-713" rel="noopener noreferrer" target="_blank">https://doi.org/10.5194/egusphere-2025-713</a>).</p> <p> </p> </div> <div> <h4>Experimental Design</h4> <p>The dataset includes soil moisture outputs from the following seven SP-MIP experiments:</p> <ol> <li>Experiment 1 (EXP1): Uses standardized global soil hydraulic parameters provided by SP-MIP to establish a baseline for inter-model variability.</li> <li>Experiment 2 (EXP2): Derives soil hydraulic parameters from SP-MIP-provided global soil textural properties using CLM5’s default pedotransfer functions (PTFs).</li> <li>Experiment 3 (EXP3): Employs CLM5’s default soil hydraulic settings, consistent across all soil layers, as a reference run.</li> <li>Experiment 4a (EXP4a): Uses spatially uniform soil parameters for loamy sand.</li> <li>Experiment 4b (EXP4b): Uses spatially uniform soil parameters for loam.</li> <li>Experiment 4c (EXP4c): Uses spatially uniform soil parameters for clay.</li> <li>Experiment 4d (EXP4d): Uses spatially uniform soil parameters for silt.</li> </ol> <div>These experiments isolate the effects of soil parameter variations on soil moisture simulations, as detailed in the SP-MIP protocol (Gudmundsson and Cuntz, 2017).</div> <div> </div> </div> <div> <div> <h4>Data Details</h4> <ul> <li>Variable: Soil moisture content in the root zone (labeled as mrlsl in CLM5 outputs), measured in kg/m².</li> <li>Temporal Coverage: Daily data from January 1, 1980, to December 31, 2010 (30 years).</li> <li>Spatial Coverage: CONUS region, spanning approximately 25°N–50°N latitude and 125°W–66°W longitude.</li> <li>Format: NetCDF files, following the SP-MIP output specification (daily outputs in annual chunks, e.g., CLM5_SPMIP_Exp_.nc, e.g., CLM5_SPMIP_Exp1_1980-2010.nc).</li> <li>Size: 2.5 GB </li> <li>Processing: Subsetted from the global CLM5 SP-MIP dataset to focus on CONUS and the root zone (0–1 m, covering the top layers of the 25-layer CLM5 soil column).</li> </ul> <p> </p> </div> </div> <div> <div> <h4>Access and Reuse</h4> <p>The dataset is provided under an open-access license (e.g., Creative Commons Attribution 4.0 International, CC BY 4.0), allowing for reuse in research, provided proper attribution is given. Users are encouraged to consult the original SP-MIP documentation and the associated publication for context and methodological details.</p> </div> </div><p>Notes:</p><p>The original global CLM5 dataset from the Soil Parameter Model Intercomparison Project (SP-MIP) is accessible via the official SP-MIP data repository (available at: ftp://sp-mip:spmip2017@data.iac.ethz.ch). For further details, users can directly contact the SP-MIP coordinators: Lukas Gudmundsson (<a href="mailto:lukas.gudmundsson@env.ethz.ch">lukas.gudmundsson@env.ethz.ch</a>) or Matthias Cuntz (<a href="mailto:Matthias.Cuntz@inrae.fr">Matthias.Cuntz@inrae.fr</a>). Users should be aware that the Global Soil Wetness Project Phase 3 (GSWP3) forcing data used in SP-MIP contains known instances of negative precipitation values; these were corrected by setting them to zero, as specified in the SP-MIP experimental protocol.</p>