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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-2026-4830</article-id>
<title-group>
<article-title>Uncertainty in an Adapted Analytic CO&lt;sub&gt;2&lt;/sub&gt; Flux Inversion Model (AACO&lt;sub&gt;2&lt;/sub&gt;FIM) under different spatiotemporal coverages</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Rong</surname>
<given-names>Pingping</given-names>
<ext-link>https://orcid.org/0000-0002-9923-0652</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>Su</surname>
<given-names>Hui</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>State Key Laboratory of Climate Resilience for Coastal Cities, Department of Civil and Environmental Engineering, the   Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR, China</addr-line>
</aff>
<pub-date pub-type="epub">
<day>20</day>
<month>08</month>
<year>2026</year>
</pub-date>
<volume>2026</volume>
<fpage>1</fpage>
<lpage>34</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2026 Pingping Rong</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-2026-4830/">This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-4830/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2026/egusphere-2026-4830/egusphere-2026-4830.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-4830/egusphere-2026-4830.pdf</self-uri>
<abstract>
<p>We developed an Adapted Analytic CO₂ Flux Inversion Model (AACO₂FIM) by adapting the Integrated Methane Inversion system for CO₂ applications. We applied AACO₂FIM to examine how closely the regulated solution aligns with predefined emission variability patterns described by target scaling factors (SFs) used to generate pseudo-observations, thereby isolating uncertainty arising solely from cost-function minimization under the quasi-linear assumption. To concurrently assess spatiotemporal coverage impacts, we revised the inversion package to incorporate two different coverage configurations: Orbiting Carbon Observatory-2 (OCO-2) tracks (oco2Trks) and an hourly global grid (FullC).&lt;/p&gt;
&lt;p&gt;Inversion performance was quantified by the convergence of inverted SFs toward target SFs under varying prior-target mismatches and observational coverages over an 8-day window following a one-month spinup. The ensemble-mean posterior SFs reproduced the target patterns, with convergence controlled by forward-model sensitivity and observational coverage. Baseline cases showed near-exact convergence, whereas larger prior-target differences led to poorer convergence. The oco2Trks inversions produced a shrunk but highly correlated valid inversion domain relative to FullC, and both configurations showed the largest posterior variability coinciding with the highest forward-model sensitivity. Under oco2Trks (&amp;lt;10 % coverage of FullC), the observation-related cost function term required a weight two orders of magnitude larger than that of FullC to achieve the best fit quality. When OCO-2 observations were used as a constraint, the inverted SF variability generally matched the bias patterns between forward-modeled concentrations and OCO-2 measurements.</p>
</abstract>
<counts><page-count count="34"/></counts>
<funding-group>
<award-group id="gs1">
<funding-source>Hong Kong Jockey Club</funding-source>
<award-id>ITS/003/24SC (P0491)</award-id>
<award-id>ITC-SKLCRCC26EG01</award-id>
</award-group>
</funding-group>
</article-meta>
</front>
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