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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-2025-5396</article-id>
<title-group>
<article-title>High latitude, dayside ULF signals observed from ground in Greenland</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Eldor</surname>
<given-names>Marie Vigger</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>Johnsen</surname>
<given-names>Magnar Gullikstad</given-names>
<ext-link>https://orcid.org/0000-0002-2776-0750</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>Olsen</surname>
<given-names>Nils</given-names>
<ext-link>https://orcid.org/0000-0003-1132-6113</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>Willer</surname>
<given-names>Anna Naemi</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Division of Geomagnetism and Geospace, DTU Space, National Space Institute, Technical University of Denmark, Akademivej 356, 2800 Kgs. Lyngby, Denmark</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Tromsø Geophysical Observatory (TGO), UiT the Arctic University of Norway, 9037 Tromsø, Norway</addr-line>
</aff>
<pub-date pub-type="epub">
<day>14</day>
<month>11</month>
<year>2025</year>
</pub-date>
<volume>2025</volume>
<fpage>1</fpage>
<lpage>17</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2025 Marie Vigger Eldor 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-2025-5396/">This article is available from https://egusphere.copernicus.org/preprints/2025/egusphere-2025-5396/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2025/egusphere-2025-5396/egusphere-2025-5396.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2025/egusphere-2025-5396/egusphere-2025-5396.pdf</self-uri>
<abstract>
<p>&lt;em&gt;Ultra-low frequency&lt;/em&gt; (ULF) waves propagate through the cusp and generate distinct summertime signatures in high latitude ground-based magnetometer measurements. In this study, we apply four years of data from the high time resolution West Greenland magnetometer chain and perform a statistical analysis of ULF signal distribution as a function of season, magnetic latitude, magnetic local time, and interplanetary magnetic field parameters. We find that ULF signals at the highest latitudes, in the cusp and beyond, are sensitive to seasonal change, indicating that the ionospheric currents that generate the signal depend on solar illumination to obtain sufficient conductivities. This effect, in concert with dipole tilt, is investigated, and a clear cusp-related ULF signal population during summer was found. In winter, this population merges with other ULF signals associated with Alfv&amp;eacute;nic interhemispheric bouncing further south and thus disappears. Earlier studies, which have mainly been performed during winter conditions, failed to unambiguously identify cusp ULF signals. Furthermore, we discuss other aspects of our statistical analysis and briefly address implications for other known cusp phenomena.</p>
</abstract>
<counts><page-count count="17"/></counts>
</article-meta>
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