<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "https://jats.nlm.nih.gov/nlm-dtd/publishing/3.0/journalpublishing3.dtd">
<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" article-type="data-paper" specific-use="SMUR" dtd-version="3.0" xml:lang="en">
<front>
<journal-meta>
<journal-id journal-id-type="publisher">ESSDD</journal-id>
<journal-title-group>
<journal-title>Earth System Science Data Discussions</journal-title>
<abbrev-journal-title abbrev-type="publisher">ESSDD</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">Earth Syst. Sci. Data Discuss.</abbrev-journal-title>
</journal-title-group>
<publisher><publisher-name></publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/essd-2026-554</article-id>
<title-group>
<article-title>A global, temporally continuous, hourly CO&lt;sub&gt;2&lt;/sub&gt; concentration dataset at GAW monitoring stations for 2000&amp;ndash;2024: Enabling fine-scale carbon dynamics analysis</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Mi</surname>
<given-names>Tan</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>Pu</surname>
<given-names>Xueting</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>Zheng</surname>
<given-names>Xi</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>Nie</surname>
<given-names>Guangcheng</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>Liu</surname>
<given-names>Xinyi</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Zhang</surname>
<given-names>Han</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>Grieneisen</surname>
<given-names>Michael L.</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>Zhan</surname>
<given-names>Yu</given-names>
<ext-link>https://orcid.org/0000-0002-8473-2799</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>Wang</surname>
<given-names>Maohua</given-names>
</name>
<xref ref-type="aff" rid="aff6">
<sup>6</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Yang</surname>
<given-names>Fumo</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>College of Carbon Neutrality Future Technology, Sichuan University, Chengdu, Sichuan  610065, China</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Department of Civil and Environmental Engineering, The Pennsylvania State University,  University Park, PA 16803, United States</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Department of Environmental Science and Engineering, Sichuan University, Chengdu, Sichuan  610065, China</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>State Grid Sichuan Electric Power Research Institute, Chengdu, Sichuan, 610041, China</addr-line>
</aff>
<aff id="aff5">
<label>5</label>
<addr-line>Department of Land, Air, and Water Resources, University of California, Davis, CA 95616,  United States</addr-line>
</aff>
<aff id="aff6">
<label>6</label>
<addr-line>Institute for Disaster Management and Reconstruction, Sichuan University-The Hong Kong  Polytechnic University, Chengdu 610207, China</addr-line>
</aff>
<pub-date pub-type="epub">
<day>06</day>
<month>10</month>
<year>2026</year>
</pub-date>
<volume>2026</volume>
<fpage>1</fpage>
<lpage>41</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2026 Tan Mi 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://essd.copernicus.org/preprints/essd-2026-554/">This article is available from https://essd.copernicus.org/preprints/essd-2026-554/</self-uri>
<self-uri xlink:href="https://essd.copernicus.org/preprints/essd-2026-554/essd-2026-554.pdf">The full text article is available as a PDF file from https://essd.copernicus.org/preprints/essd-2026-554/essd-2026-554.pdf</self-uri>
<abstract>
<p>Global Atmosphere Watch (GAW) carbon dioxide (CO&lt;sub&gt;2&lt;/sub&gt;) observations provide high-precision constraints on surface CO&lt;sub&gt;2&lt;/sub&gt; variability, but many station records remain temporally incomplete because of flask sampling, instrument interruptions, and quality-control exclusions. Such gaps can limit the representation of diurnal variability, bias daily, monthly, and annual mean CO&lt;sub&gt;2&lt;/sub&gt; estimates, and reduce the ability to detect short-lived events. Here, we present a global, temporally continuous hourly reconstruction dataset of GAW station CO&lt;sub&gt;2&lt;/sub&gt; concentrations for 2000&amp;ndash;2024. The dataset was generated using a two-stage reconstruction framework that integrates GAW observations with Carbon Tracker (CT) and Copernicus Atmosphere Monitoring Service (CAMS) CO&lt;sub&gt;2&lt;/sub&gt; fields, together with anthropogenic, vegetation, meteorological, and spatiotemporal predictors. In the intra-day gap filling stage, missing hours on days with at least one valid observation were reconstructed using hour-pair models to produce complete daily profiles. In the full-sequence reconstruction stage, the remaining periods with no valid observations were reconstructed using a globally trained initial prediction model followed by station-specific post-correction. The framework showed robust validation performance at the hourly scale, with &lt;em&gt;R&lt;/em&gt;&lt;sup&gt;2&lt;/sup&gt; = 0.96 and RMSE = 3.65 ppm for intra-day gap filling and &lt;em&gt;R&lt;/em&gt;&lt;sup&gt;2&lt;/sup&gt; = 0.93 and RMSE = 4.76 ppm for full-sequence reconstruction. Across all stations, the mean filling rate was 68.9 %, and the mean reconstruction uncertainty was 2.80 ppm. Applying the World Data Centre for Greenhouse Gases (WDCGG) global analysis framework showed that reconstructed global monthly mean CO&lt;sub&gt;2&lt;/sub&gt; concentrations were, on average, 0.54 &amp;plusmn; 0.21 ppm higher than those derived from the original GAW records, indicating that incomplete temporal coverage can measurably affect global monthly estimates. Compared with grid-cell CT and CAMS simulations, the reconstructed dataset retained stronger station-scale diurnal variability and captured CO&lt;sub&gt;2&lt;/sub&gt; enhancements during the 2023 Canadian wildfire period. This dataset can support long-term assessments of global and regional surface CO&lt;sub&gt;2&lt;/sub&gt; changes, fine-scale analyses of CO&lt;sub&gt;2&lt;/sub&gt; variability, and regional carbon emission inversion and evaluation. The dataset is available at &lt;a href=&quot;https://doi.org/10.5281/zenodo.21306261&quot; target=&quot;_blank&quot; rel=&quot;noopener&quot;&gt;https://doi.org/10.5281/zenodo.21306261&lt;/a&gt; (Mi et al., 2026).</p>
</abstract>
<counts><page-count count="41"/></counts>
</article-meta>
</front>
<body/>
<back>
</back>
</article>