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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-2026-2925</article-id>
<title-group>
<article-title>Thermospheric shock waves and lensing of light in the Barium Release, Optical and Radio rocket experiment</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Leyser</surname>
<given-names>Thomas B.</given-names>
<ext-link>https://orcid.org/0000-0001-9694-197X</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>Sergienko</surname>
<given-names>Tima</given-names>
<ext-link>https://orcid.org/0000-0003-4515-2174</ext-link>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Yokoyama</surname>
<given-names>Yoshihiro</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>Taki</surname>
<given-names>Tomoe</given-names>
<ext-link>https://orcid.org/0000-0003-0193-0966</ext-link>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Brändström</surname>
<given-names>Urban</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Swedish Institute of Space Physics, Uppsala, Sweden</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Swedish Institute of Space Physics, Kiruna, Sweden</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Department of Physics and Technology, UiT The Arctic University of Norway, Tromsø, Norway</addr-line>
</aff>
<pub-date pub-type="epub">
<day>30</day>
<month>06</month>
<year>2026</year>
</pub-date>
<volume>2026</volume>
<fpage>1</fpage>
<lpage>21</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2026 Thomas B. Leyser 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-2026-2925/">This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-2925/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2026/egusphere-2026-2925/egusphere-2026-2925.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-2925/egusphere-2026-2925.pdf</self-uri>
<abstract>
<p>The Barium Release, Optical and Radio (BROR) rocket experiment, launched from Esrange near Kiruna, Sweden, involved eight releases of barium at different altitudes in the thermosphere to study electric fields near small scale auroral structures. The barium was ejected into the thermosphere by the explosion-like combustion of ignited copper oxide thermite. Shock waves could be observed optically from the ground to follow the barium ejections when the rocket speed was supersonic, but not when it was subsonic. The shock waves are attributed to copper droplets that resulted from the thermite combustion and other particulate matter in the ejecta that traveled at supersonic speed. The observed deceleration of the shock waves can be explained by frictional drag together with gravity on copper droplets having a mean radius of about 1 mm. The actual observation of the shock waves from the ground is attributed to scattering of sunlight on the particulate matter in the ejecta. Also, following the ejections at the highest speeds, optical lensing of sunlight reflected from the rocket itself was observed, in that the rocket appeared brighter just after the barium release than before the release.</p>
</abstract>
<counts><page-count count="21"/></counts>
<funding-group>
<award-group id="gs1">
<funding-source>Swedish National Space Agency</funding-source>
<award-id>2024-00232</award-id>
</award-group>
</funding-group>
</article-meta>
</front>
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