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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-2026-5386</article-id>
<title-group>
<article-title>From profiles to swaths: First estimates of Arctic sea ice freeboard and thickness from SWOT (2023&amp;ndash;2025)</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Kacimi</surname>
<given-names>Sahra</given-names>
<ext-link>https://orcid.org/0000-0003-0884-6038</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>Jaruwatanadilok</surname>
<given-names>Sermsak</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>Kwok</surname>
<given-names>Ron</given-names>
<ext-link>https://orcid.org/0000-0003-4051-5896</ext-link>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA</addr-line>
</aff>
<pub-date pub-type="epub">
<day>10</day>
<month>09</month>
<year>2026</year>
</pub-date>
<volume>2026</volume>
<fpage>1</fpage>
<lpage>29</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2026 Sahra Kacimi 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-2026-5386/">This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-5386/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2026/egusphere-2026-5386/egusphere-2026-5386.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-5386/egusphere-2026-5386.pdf</self-uri>
<abstract>
<p>We present our first estimates of Arctic sea ice freeboard, sea surface height (SSH) from leads, and sea ice thickness from SWOT wide-swath altimetry, which span two growth seasons between October 2023 and April 2025. An incidence-angle-dependent classification scheme separates returns from leads and ice floes for freeboard retrievals. Open water leads, for freeboard calculations, are characterized by high radar backscatter, and low surface heights. Separation of returns from ice floes and leads yields, as expected, spatially decoupled fields of sea surface height and freeboard. Comparisons of area-averaged ICESat-2 and SWOT estimates of lead SSH anomalies over two Arctic growth seasons show strong agreement (&lt;em&gt;R&lt;/em&gt;&lt;sup&gt;2&lt;/sup&gt; = 0.95, slope = 0.91), with mean differences ranging between &amp;minus;8.33 &amp;plusmn; 8.0 cm and 2.62 &amp;plusmn; 10.1 cm. The area-averaged freeboard estimates from ICESat-2 are consistently higher than those from SWOT, with differences that trend from a low of &amp;minus;0.78 &amp;plusmn; 4.22 cm in early fall, to a high of 11.3 &amp;plusmn; 5.79 cm in early spring. Regression analysis of the two freeboard records shows consistent seasonal variability, explained largely by the expected growth of the sea ice cover (&lt;em&gt;R&lt;/em&gt;&lt;sup&gt;2 &lt;/sup&gt;= 0.96). This seasonal behavior of ICESat-2 and SWOT freeboard differences strongly mirrors altimeter-derived snow depths (&lt;em&gt;R&lt;/em&gt; = 0.99 and 0.97 for the 2023&amp;ndash;2024 and 2024&amp;ndash;2025 seasons), suggesting a time-invariant &lt;em&gt;Ka&lt;/em&gt;-band penetration depth into the snow cover. Comparisons between ICESat-2 and SWOT sea ice thicknesses&amp;mdash;using SWOT total freeboard&amp;mdash;reveal close overall agreement, with a mean difference of 0.02 &amp;plusmn; 0.17 m for the two seasons.</p>
</abstract>
<counts><page-count count="29"/></counts>
<funding-group>
<award-group id="gs1">
<funding-source>National Aeronautics and Space Administration</funding-source>
<award-id>80NM0018D0004</award-id>
</award-group>
</funding-group>
</article-meta>
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