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<p class="MsoNormal">Hi Elian,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I would look at your tracer fields. Is that maybe just (poorly resolved) convection?
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Cheers, Jody<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b><span lang="NL" style="font-size:12.0pt;font-family:"Calibri",sans-serif;color:black;mso-ligatures:none">From:
</span></b><span lang="NL" style="font-size:12.0pt;font-family:"Calibri",sans-serif;color:black;mso-ligatures:none">MITgcm-support <mitgcm-support-bounces@mitgcm.org> on behalf of "Vanderborght, E.Y.P. (Elian)" <e.y.p.vanderborght@uu.nl><br>
<b>Reply-To: </b>"mitgcm-support@mitgcm.org" <MITgcm-support@mitgcm.org><br>
<b>Date: </b>Thursday, April 3, 2025 at 8:25 AM<br>
<b>To: </b>MITgcm Support <MITgcm-support@mitgcm.org><br>
<b>Subject: </b>[MITgcm-support] Irregular Velocity Fields Near Basin Boundaries in MITgcm<o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="NL" style="font-size:12.0pt;mso-ligatures:none"><o:p> </o:p></span></p>
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<span style="font-size:9.0pt;font-family:"Segoe UI",sans-serif;color:#212121;mso-ligatures:none">You don't often get email from e.y.p.vanderborght@uu.nl.
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<o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US">Dear MITgcm community,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">I am running MITgcm in a rectangular basin with a single-hemisphere setup. However, I am encountering irregularities in both vertical and horizontal velocity fields near the basin boundaries (see attached figure).<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Initially, I suspected insufficient horizontal viscosity. While increasing it to unrealistically high values reduced the issue, it did not resolve it entirely.
</span><span lang="NL">I have also tested the following:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<ul style="margin-top:0cm" type="disc">
<li class="MsoListParagraph" style="margin-left:0cm;mso-list:l1 level1 lfo3"><span lang="EN-US">Decreasing time-step,<o:p></o:p></span></li><li class="MsoListParagraph" style="margin-left:0cm;mso-list:l1 level1 lfo3"><span lang="EN-US">Using different advection schemes,<o:p></o:p></span></li><li class="MsoListParagraph" style="margin-left:0cm;mso-list:l1 level1 lfo3"><span lang="EN-US">Increasing horizontal diffusion,<o:p></o:p></span></li><li class="MsoListParagraph" style="margin-left:0cm;mso-list:l1 level1 lfo3"><span lang="EN-US">Increasing vertical viscosity.<o:p></o:p></span></li></ul>
<p class="MsoListParagraph"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">None of these approaches have fully addressed the problem. I have also reviewed studies using similar setups, but they do not report encountering this issue. Does anyone have insights into what might be causing this or
suggestions for a fix? I have attached my data file and SIZE.h for reference.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Any help would be greatly appreciated.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Best regards,<br>
Elian<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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