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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-2025-778</article-id>
<title-group>
<article-title>Seasonal isoprene emission estimates over tropical South America inferred from satellite observations of isoprene</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Sun</surname>
<given-names>Shihan</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>Palmer</surname>
<given-names>Paul I.</given-names>
<ext-link>https://orcid.org/0000-0002-1487-0969</ext-link>
</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>Siddans</surname>
<given-names>Richard</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Kerridge</surname>
<given-names>Brian J.</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Ventress</surname>
<given-names>Lucy</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Edtbauer</surname>
<given-names>Achim</given-names>
<ext-link>https://orcid.org/0000-0001-8824-2132</ext-link>
</name>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Ringsdorf</surname>
<given-names>Akima</given-names>
<ext-link>https://orcid.org/0000-0002-1764-6516</ext-link>
</name>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Pfannerstill</surname>
<given-names>Eva Y.</given-names>
<ext-link>https://orcid.org/0000-0001-7715-1200</ext-link>
</name>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Williams</surname>
<given-names>Jonathan</given-names>
<ext-link>https://orcid.org/0000-0001-9421-1703</ext-link>
</name>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
<xref ref-type="aff" rid="aff6">
<sup>6</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>National Centre for Earth Observation, University of Edinburgh, Edinburgh, EH9 3FF, UK</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>School of GeoSciences, University of Edinburgh, Edinburgh, EH9 3FF, UK</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Remote Sensing Group, STFC Rutherford Appleton Laboratory, Chilton, Oxfordshire, OX11 0QX, UK</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>National Centre for Earth Observation, STFC Rutherford Appleton Laboratory, Chilton, Oxfordshire, OX11 0QX, UK</addr-line>
</aff>
<aff id="aff5">
<label>5</label>
<addr-line>Max Planck Institute for Chemistry, Atmospheric chemistry department, Mainz, Germany</addr-line>
</aff>
<aff id="aff6">
<label>6</label>
<addr-line>Climate and Atmosphere Research Center (CARE-C), The Cyprus Institute, 1070 Nicosia, Cyprus</addr-line>
</aff>
<pub-date pub-type="epub">
<day>26</day>
<month>02</month>
<year>2025</year>
</pub-date>
<volume>2025</volume>
<fpage>1</fpage>
<lpage>28</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2025 Shihan Sun 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-2025-778/">This article is available from https://egusphere.copernicus.org/preprints/2025/egusphere-2025-778/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2025/egusphere-2025-778/egusphere-2025-778.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2025/egusphere-2025-778/egusphere-2025-778.pdf</self-uri>
<abstract>
<p>Isoprene, a volatile organic compound (VOC) emitted by plants, plays a significant role in atmospheric chemistry and climate. The Amazon rainforest is a globally-relevant source of atmospheric isoprene, influencing regional and global atmospheric composition. We report isoprene emissions for 2019 inferred from the Cross-track Infrared Sounder (CrIS) and the local sensitivities between isoprene emissions and isoprene columns determined by the GEOS-Chem chemical transport model. Compared with the MEGAN bottom-up inventory of isoprene emissions, the isoprene emission estimates inferred from CrIS have different spatial and seasonal distributions with generally lower emission rates but with higher emission rates over the north of Amazon basin and southeast of Brazil. Isoprene mole fraction data collected at the Amazon Tall Tower Observatory (ATTO) are invaluable for evaluating isoprene emission estimates. The observed mean isoprene concentration at ATTO, March&amp;mdash;December 2019, is 3.0 &amp;plusmn; 2.2 ppbv, which is reproduced better by the GEOS-Chem model driven by isoprene emissions inferred from CrIS (2.8 &amp;plusmn; 1.4 ppbv) than by the MEGAN inventory (4.1&amp;plusmn;1.3 ppbv). GEOS-Chem model formaldehyde (HCHO) columns, corresponding to isoprene emissions inferred from CrIS, are generally more consistent with TROPOMI data (normalized mean error, NME = 43 %) than the HCHO columns corresponding to MEGAN isoprene emissions (NME = 50 %), as expected. They also improve the model agreement with regional TROPOMI HCHO:NO&lt;sub&gt;2&lt;/sub&gt; column ratios that are indicative of changes in photochemical regime. Our results provide confidence that we can use CrIS data to examine future impacts of anthropogenic activities on isoprene emissions from the Amazon.</p>
</abstract>
<counts><page-count count="28"/></counts>
<funding-group>
<award-group id="gs1">
<funding-source>National Centre for Earth Observation</funding-source>
<award-id>NE/R016518/1</award-id>
</award-group>
</funding-group>
</article-meta>
</front>
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