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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-2025-351</article-id>
<title-group>
<article-title>Contribution of gravity waves to shear in the extratropical lowermost stratosphere: insights from idealized baroclinic life cycle experiments</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Umbarkar</surname>
<given-names>Madhuri</given-names>
<ext-link>https://orcid.org/0009-0009-9485-0762</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>Kunkel</surname>
<given-names>Daniel</given-names>
<ext-link>https://orcid.org/0000-0002-9652-0099</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Institute for Atmospheric Physics, Johannes Gutenberg University Mainz, Germany</addr-line>
</aff>
<pub-date pub-type="epub">
<day>28</day>
<month>02</month>
<year>2025</year>
</pub-date>
<volume>2025</volume>
<fpage>1</fpage>
<lpage>33</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2025 Madhuri Umbarkar</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-2025-351/">This article is available from https://egusphere.copernicus.org/preprints/2025/egusphere-2025-351/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2025/egusphere-2025-351/egusphere-2025-351.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2025/egusphere-2025-351/egusphere-2025-351.pdf</self-uri>
<abstract>
<p>Mixing significantly influences the redistribution of trace species in the lower stratosphere, potentially being the dominant factor in forming the extratropical transition layer (ExTL). However, the role of small-scale processes contributing to mixing is poorly characterized. In the extratropics, mixing processes are often linked to stratosphere-troposphere exchange (STE), which occurs frequently during baroclinic life cycles, e.g., near tropopause folds, cut-off lows, or stratospheric streamers. Gravity waves (GWs), a dynamical feature of these life cycles, can potentially contribute to STE and mixing in the lower stratosphere. We present a series of baroclinic life cycle experiments with the ICOsahedral Nonhydrostatic (ICON) model to study the impact of GWs on the occurrence of vertical wind shear and consequent potential turbulence, an indicator for mixing in the lowermost stratosphere (LMS). Dry adiabatic simulations with varying spatial resolution reveal that the spatiotemporal occurrence of GWs depends on model grid spacing and is closely linked to shear and turbulence generation. Further process understanding is gained from experiments incorporating physical processes like latent heating, (vertical) turbulence, and cloud microphysics. Introducing moist processes amplifies GW activity and turbulence potential, mainly driven by latent heat release and stronger baroclinic wave evolution with vigorous vertical motions. Turbulence parameterization has a lesser effect on the overall evolution without moisture, while it dampens the effect of latent heat release in moist simulations. Altogether, GWs substantially enhance vertical shear and potential turbulence occurrence in the LMS and thus can play a significant role in tracer mixing and, consequently, in the ExTL formation.</p>
</abstract>
<counts><page-count count="33"/></counts>
<funding-group>
<award-group id="gs1">
<funding-source>Deutsche Forschungsgemeinschaft</funding-source>
<award-id>TRR 301 – Project-ID 428312742, TPChange</award-id>
</award-group>
</funding-group>
</article-meta>
</front>
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