<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;">Hi Jodi, perhaps a good place to start would be to understand cause of the larger oscillations in MEDSEA and ROMS, which might then help you diagnose what is missing in your MITgcm configuration. For example, if the ~10-day oscillation in MEDSEA and ROMS is primarily caused by transport through Gibraltar Strait, then you could look at MITgcm’s transport through Gibraltar Strait to see whether it has been correctly prescribed.<div><br></div><div>D.<br id="lineBreakAtBeginningOfMessage"><div><br><blockquote type="cite"><div>On Jul 8, 2025, at 6:13 AM, Jordi Iglesias <jiglesias@icm.csic.es> wrote:</div><br class="Apple-interchange-newline"><div>
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<div style="padding-bottom: 1px;"><p>Dear MITgcm community,<br>
<br>
Over the past few months, I’ve been struggling to achieve
realistic sea surface height ("Eta") results in my MITgcm
simulations. I’ve tried several configurations,including
non-hydrostatic, quasi-non-hydrostatic, and nonlinear free surface
options, but the SSH output often differs significantly from the
parent model (the Copernicus Mediterranean analysis, MEDSEA). I’ve
attached an example and also shared a link to illustrate the
issue. I have tides configured, and the ssh is initialized from
MEDSEA data. However, when I compare the SSH output with the
parent model (or with a ROMS simulation, for example), it appears
to oscillate around a constant value that doesn’t evolve much over
time, or changes are very small.<br>
<br>
A summary of my configuration: Horizontal resolution: 1.6 km, NW
Mediterranean Sea, Atmospheric forcing: ECMWF, initial ssh set
with pSurfInitFile, SphericalPolarGrid, quasiHydrostatic = .TRUE.,
nonlinFreeSurf = 3, rigidLid = .FALSE., implicitFreeSurface =
.TRUE., <br>
</p><p>If any additional parameters would help diagnose the issue, I’d
be happy to provide them.<br>
<br>
The temperature, salinity, and velocity fields are generally in
good agreement with ROMS and MEDSEA, but I’d really like to
improve the SSH performance. Has anyone encountered a similar
issue or found strategies to improve SSH in MITgcm?<br>
<br>
Thanks in advance for your help!<br>
<br>
Best regards,<br>
Jordi<br>
<br>
<a class="moz-txt-link-freetext" href="https://saco.csic.es/s/c2fSgN5RWPRcDSQ">https://saco.csic.es/s/c2fSgN5RWPRcDSQ</a><br>
</p><p><br>
</p>
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