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<front>
<journal-meta>
<journal-id journal-id-type="publisher">EGUsphere</journal-id>
<journal-title-group>
<journal-title>EGUsphere</journal-title>
<abbrev-journal-title abbrev-type="publisher">EGUsphere</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">EGUsphere</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1991-962X</issn>
<publisher><publisher-name>Copernicus Publications</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/egusphere-2025-713</article-id>
<title-group>
<article-title>Soil Parameterization in Land Surface Models Drives Large Discrepancies in Soil Moisture Predictions Across Hydrologically Complex regions of the Contiguous United States</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Silwimba</surname>
<given-names>Kachinga</given-names>
<ext-link>https://orcid.org/0009-0005-9013-1032</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Flores</surname>
<given-names>Alejandro N.</given-names>
<ext-link>https://orcid.org/0000-0002-7240-9265</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Cionni</surname>
<given-names>Irene</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Billings</surname>
<given-names>Sharon A.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Sullivan</surname>
<given-names>Pamela L.</given-names>
<ext-link>https://orcid.org/0000-0001-8780-8501</ext-link>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Ajami</surname>
<given-names>Hoori</given-names>
</name>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Hirmas</surname>
<given-names>Daniel R.</given-names>
</name>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Li</surname>
<given-names>Li</given-names>
<ext-link>https://orcid.org/0000-0002-1641-3710</ext-link>
</name>
<xref ref-type="aff" rid="aff6">
<sup>6</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Department of Geosciences, Boise State University, Boise, ID, USA</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Department of Ecology and Evolutionary Biology and Kansas Biological Survey &amp; Center for Ecological Research, University of Kansas, Lawrence, KS, USA</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, OR, USA</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>Department of Environmental Sciences, University of California Riverside, Riverside, CA, USA</addr-line>
</aff>
<aff id="aff5">
<label>5</label>
<addr-line>Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, USA</addr-line>
</aff>
<aff id="aff6">
<label>6</label>
<addr-line>Department of Civil and Environmental Engineering, Pennsylvania State University, University Park, PA, USA</addr-line>
</aff>
<pub-date pub-type="epub">
<day>27</day>
<month>02</month>
<year>2025</year>
</pub-date>
<volume>2025</volume>
<fpage>1</fpage>
<lpage>36</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2025 Kachinga Silwimba et al.</copyright-statement>
<copyright-year>2025</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by/4.0/">https://creativecommons.org/licenses/by/4.0/</ext-link></license-p>
</license>
</permissions>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2025/egusphere-2025-713/">This article is available from https://egusphere.copernicus.org/preprints/2025/egusphere-2025-713/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2025/egusphere-2025-713/egusphere-2025-713.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2025/egusphere-2025-713/egusphere-2025-713.pdf</self-uri>
<abstract>
<p>Land surface models (LSMs) are critical components of Earth system models (ESMs), enabling simulations of energy and water fluxes essential for understanding climate systems. Soil hydraulic parameters, derived using pedotransfer functions (PTFs), are key to modeling soil-plant-water interactions but introduce uncertainties in soil moisture predictions. However, a key knowledge gap exists in understanding how specific soil hydraulic properties contribute to these uncertainties and in identifying the regions most affected by them. This study assesses the influence of soil parameter settings on soil moisture variability in the Community Land Model version 5 (CLM5) over the contiguous United States (CONUS) using Empirical Orthogonal Function (EOF) analysis. EOF analysis identified dominant spatial and temporal soil moisture patterns across multiple experimental configurations and highlighted the impact of soil parameter variability on hydrological processes. The results revealed significant discrepancies in soil moisture simulations, particularly in the central Great Plains, potentially due to the combination of arid climate conditions and limitations in modeling saturated hydraulic conductivity and soil water retention curves. Seasonal soil moisture dynamics aligned broadly with observed patterns but showed biases in magnitude and phase, emphasizing the need for refined parameterization, such as improving the representation of infiltration and drainage processes. Comparisons with ERA5-Land reanalysis data revealed improved alignment in regions with consistent climatic gradients but persistent model deficiencies in hydrologically complex areas, particularly under more arid climates such as the Great Plains where hydrological processes are notoriously harder to reproduce. This research highlights the necessity of refining soil parameter representations, utilizing high-resolution datasets, and considering climatic variability to boost the performance of LSMs. Importantly, these findings also open the door to future efforts that incorporate dynamic soil properties into LSMs. Much of this work demonstrates the dynamism of soil properties, and while this study advances modeling by revealing the importance of their inclusion, the next crucial step will be developing approaches that allow these properties to be dynamic within LSMs. This paper serves as a foundational step toward that goal, paving the way for more complex and integrated modeling frameworks that better capture soil-hydrology-climate interactions.</p>
</abstract>
<counts><page-count count="36"/></counts>
<funding-group>
<award-group id="gs1">
<funding-source>National Science Foundation</funding-source>
<award-id>2121760</award-id>
<award-id>2121694</award-id>
<award-id>2121639</award-id>
<award-id>2121621</award-id>
<award-id>2121595</award-id>
<award-id>2034232</award-id>
<award-id>2034214</award-id>
</award-group>
<award-group id="gs2">
<funding-source>National Institute of Food and Agriculture</funding-source>
<award-id>2021-67019-34341</award-id>
<award-id>2021-67019-34338</award-id>
<award-id>2021-67019-34340</award-id>
</award-group>
<award-group id="gs3">
<funding-source>U.S. Department of Agriculture</funding-source>
<award-id>2021-67019-34338</award-id>
</award-group>
</funding-group>
</article-meta>
</front>
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<back>
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