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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-2026-1683</article-id>
<title-group>
<article-title>Near-Real-Time Assimilation of Satellite-Derived Ocean Surface Currents Using a Multi-Model Ensemble Kalman Filter</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Baig</surname>
<given-names>Shahbaz</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>Qazi</surname>
<given-names>Waqas A.</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>Mumtaz</surname>
<given-names>Rafia</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>School of Engineering and Computer Science, National University of Sciences and Technology, H-12, Islamabad, 44000, ICT, Pakistan</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>MetOcean, 26 Nikou Pattichi Street, 3071, O. M. Offshore Monitoring Ltd., Limassol, 4102, Cyprus</addr-line>
</aff>
<pub-date pub-type="epub">
<day>07</day>
<month>04</month>
<year>2026</year>
</pub-date>
<volume>2026</volume>
<fpage>1</fpage>
<lpage>45</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2026 Shahbaz Baig 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-2026-1683/">This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-1683/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2026/egusphere-2026-1683/egusphere-2026-1683.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-1683/egusphere-2026-1683.pdf</self-uri>
<abstract>
<p>Accurate near-real-time (NRT) estimation of ocean surface currents remains challenging due to sparse in-situ observations and structural model uncertainties. Most operational systems primarily assimilate altimeter-derived geostrophic currents, which omit ageostrophic contributions from wind forcing, coastal processes, and transient mesoscale dynamics. Direct assimilation of satellite-derived ocean surface currents therefore provides a pathway to improve the dynamical consistency of NRT surface current estimates, particularly in regions of highly variable circulation where accurate knowledge of the evolving ocean state is critical for marine operations. We present an end-to-end framework for direct assimilation of high-resolution satellite-derived surface current fields into a Multi-model Ensemble Kalman Filter (MEnKF). Surface currents are retrieved using an adaptive, constrained Maximum Cross-Correlation (MCC) algorithm applied to sequential AVHRR thermal imagery. The Earth Observation (EO)-derived currents are then integrated into a heterogeneous ensemble of global and regional forecasts to explicitly account for structural model uncertainty. Evaluation against coastal HF-Radar observations and regional reanalysis confirms statistically significant improvements over background forecasts. Under optimal observational conditions, the lowest RMSE (0.18 m/s) occurs when 9&amp;ndash;12 EO-derived surface current products contribute to each assimilation cycle, accompanied by improved directional consistency relative to reanalysis data. Sensitivity analysis reveals that performance is driven by observational density and spatial representativeness, with maximum skill achieved at intermediate densities of 8&lt;span&gt;&amp;ndash;&lt;/span&gt;12 images per assimilation cycle. This framework provides a scalable, physically consistent pathway for improving NRT predictions in data-sparse regions.</p>
</abstract>
<counts><page-count count="45"/></counts>
<funding-group>
<award-group id="gs1">
<funding-source>European Commission</funding-source>
<award-id>820593</award-id>
</award-group>
<award-group id="gs2">
<funding-source>European Commission</funding-source>
<award-id>101077026</award-id>
</award-group>
</funding-group>
</article-meta>
</front>
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