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<p class="MsoNormal"><span style="font-size:11.0pt">Hi Sean<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">This is probably outdated, but the writeup and the diagnostic may help you with your problem:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><a href="https://ocean-physics.seos.uvic.ca/~jklymak/MITgcm/">https://ocean-physics.seos.uvic.ca/~jklymak/MITgcm/</a><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">in particular <a href="https://ocean-physics.seos.uvic.ca/~jklymak/MITgcm/energy_diagnostics_fill.F">
https://ocean-physics.seos.uvic.ca/~jklymak/MITgcm/energy_diagnostics_fill.F</a><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">and <o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><a href="https://ocean-physics.seos.uvic.ca/~jklymak/MITgcm/EnergyDiagnostic.pdf">https://ocean-physics.seos.uvic.ca/~jklymak/MITgcm/EnergyDiagnostic.pdf</a><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">This was used extensively in</span>
<span style="font-size:11.0pt"><a href="https://doi.org/10.1175/2010JPO4396.1" target="_blank">10.1175/2010JPO4396.1</a> and 10.1175/JPO-D-16-0061.1<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Hopefully that helps, if not, I can probably provide more guidance.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Cheers Jody<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-family:"Calibri",sans-serif;color:black">From:
</span></b><span style="font-family:"Calibri",sans-serif;color:black">MITgcm-support <mitgcm-support-bounces@mitgcm.org> on behalf of "Shiqiang Hu (ENV - Postgraduate Researcher)" <Shiqiang.Hu@uea.ac.uk><br>
<b>Reply-To: </b>"mitgcm-support@mitgcm.org" <mitgcm-support@mitgcm.org><br>
<b>Date: </b>Friday, July 18, 2025 at 9:58 AM<br>
<b>To: </b>"mitgcm-support@mitgcm.org" <mitgcm-support@mitgcm.org><br>
<b>Subject: </b>[MITgcm-support] Question about internal tide energy flux balance<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<span style="font-size:9.0pt;font-family:"wf_segoe-ui_normal",serif;color:#212121">You don't often get email from shiqiang.hu@uea.ac.uk.
<a href="https://aka.ms/LearnAboutSenderIdentification">Learn why this is important</a>
<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black">Hi MITgcm commuity,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="color:black">Hope you all well.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="color:black">I built an idealized 3D internal tide model based on
<a href="https://github.com/MITgcm/MITgcm/blob/master/verification/internal_wave" title="https://github.com/MITgcm/MITgcm/blob/master/verification/internal_wave">
internal_wave experiment</a> to calculate the energy flux F=<u'p'>(<a href="https://doi.org/10.1175/JTECH1784.1" title="https://doi.org/10.1175/JTECH1784.1">Nash et al., 2005</a>). Periodic 1-mode internal tides propagate to the right and interact with a simple
topography. The model works but I got stuck at the energy flux balance part. Sometimes when I chose a small area within the topography to calculate the net energy flux across its boundary, the result is positive, which means there are rather dissipation but
genaration of enerny. So I wanna ask if someone has experience with this. <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black">Basically, I use <i>RHOAnoma</i>+<i>rhoConst</i> to get original density
<i>rho</i>, cause the paper gets density anomaly from <i><span style="background:white">rho(z,t)-rho_mean(z),
</span></i><span style="background:white">where<i> rho_mean(z) </i>is the time mean vertical density profile (I guess I could also just use the
<i>Rhoref(z) </i>as the reference profile?). The question is the C-grids, should I calculate these values on T-points or U-V points so the energy could be more balenced? Or maybe some other factors I didn't realize? </span><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black;background:white">By the way, the non-hydrostatic pressure is quite small, so I ignored it.</span><span style="color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="color:black;background:white">Thanks for any suggestions.</span><span style="color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black;background:white">Kind regards,</span><span style="color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="color:black;background:white">Sean</span><span style="color:black"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black">University of East Anglia<o:p></o:p></span></p>
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