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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"></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-2026-2044</article-id>
<title-group>
<article-title>Hyperparameter-Optimized Inversion Modeling Framework for Urban CO&lt;sub&gt;2&lt;/sub&gt; Emission Estimation and Uncertainty Evaluation</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Xu</surname>
<given-names>Wei</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Ren</surname>
<given-names>Ge</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Du</surname>
<given-names>Kailun</given-names>
<ext-link>https://orcid.org/0000-0002-3608-4846</ext-link>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Liu</surname>
<given-names>Gege</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Zhao</surname>
<given-names>Shiqi</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>Wang</surname>
<given-names>Xiaoning</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>Han</surname>
<given-names>Mengjuan</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>Lin</surname>
<given-names>Hong</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Whetstone</surname>
<given-names>James</given-names>
<ext-link>https://orcid.org/0000-0002-5139-9176</ext-link>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Division of Thermophysics Metrology, National Institute of Metrology, Beijing 100029, China</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Zhengzhou Institute of Metrology, Zhengzhou 450001, China</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA</addr-line>
</aff>
<pub-date pub-type="epub">
<day>23</day>
<month>06</month>
<year>2026</year>
</pub-date>
<volume>2026</volume>
<fpage>1</fpage>
<lpage>33</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2026 Wei Xu et al.</copyright-statement>
<copyright-year>2026</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/2026/egusphere-2026-2044/">This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-2044/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2026/egusphere-2026-2044/egusphere-2026-2044.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-2044/egusphere-2026-2044.pdf</self-uri>
<abstract>
<p>Urban areas, occupying only 3% of the global land surface yet generating approximately 70% of anthropogenic carbon emissions, are critical targets for climate change mitigation. Accurate emission quantification remains challenging, as most atmospheric inversion studies neglect spatiotemporal correlations in prior fluxes and observation errors, inflating uncertainties in both the spatial distribution and magnitude of greenhouse gases. This study introduces an inversion framework integrating explicit correlation functions, hierarchical Bayesian modeling, and maximum-likelihood estimation, thereby removing reliance on empirical parameterization in error covariance matrices. Application to the urban core of Zhengzhou demonstrated superior performance over conventional approaches. In controlled experiments, the framework achieved superior precision in localizing high-emission sources, reducing root-mean-square error by 21.4% between posterior estimates and assumed true fluxes across multiple emission scenarios. Real-world validation at the two monitoring towers further confirmed the improvements under the EDGAR-based prior, with lower RMSE values (10.31 and 10.05 ppm) and higher correlation coefficients (0.91 and 0.81) than conventional benchmarks. Additionally, the relative uncertainty of posterior emissions declined by approximately 46.4% compared to the traditional method, reflecting the enhanced precision of the approach. Crucially, analysis indicated that the reduction in posterior uncertainty resulted from systematic examination of inter-grid correlations, demonstrating that spatial correlations are essential for rigorous uncertainty quantification.</p>
</abstract>
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