<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 Chengyan,<div><br></div><div>If you want to recreate atmospheric forcing for LLC4320, the atmospheric pressure plus tidal forcing is available here:</div><div><a href="https://ecco.jpl.nasa.gov/drive/files/ECCO2/atmos/ECMWF_operational">https://ecco.jpl.nasa.gov/drive/files/ECCO2/atmos/ECMWF_operational</a></div><div><br></div><div>However, since the LLC4320 simulation was carried out, better ways to include tides in MITgcm have been implemented:</div><div><br></div><div>1. Jean-Michel Campin added the capability to prescribe tidal forcing separately from atmospheric pressure forcing. Search for “tidePot” in <a href="https://github.com/MITgcm/MITgcm/tree/master/pkg/exf">https://github.com/MITgcm/MITgcm/tree/master/pkg/exf</a></div><div><br></div><div>2. Oliver Jahn integrated the JPL SPICE library in MITgcm, see: <a href="http://mailman.mitgcm.org/pipermail/mitgcm-support/2023-May/013438.html">http://mailman.mitgcm.org/pipermail/mitgcm-support/2023-May/013438.html</a></div><div><br></div><div>If you carry out a regional simulation in. A large domain, you will need to apply both tidal currents at the lateral boundary conditions as well as tidal potential using one of the two methods above.</div><div><br></div><div>Dimitris</div><div><br id="lineBreakAtBeginningOfMessage"><div><br><blockquote type="cite"><div>On Nov 28, 2024, at 7:08 PM, whale <250107302@qq.com> wrote:</div><br class="Apple-interchange-newline"><div><meta http-equiv="Content-Type" content="text/html; charset=GB18030"><div><div>Dear MITgcm users</div><div><br></div><div>I am trying to configure a regional model with tides included. The usual way is to prescribe the barotropic tidal forcing at the open boundaries of a regional model, and I can do it with this method in my regional model.</div><div><br></div><div>However, if the model domain is relatively larger, it would be better to prescribe the tidal potential at each bin than the tidal forcing on open boundaries. It seems that the well-known LLC4320 experiment successfully added tides by using tidal potential at every grid.</div><div><br></div><div>The tidal forcing of LLC4320 is documented by Rocha et al. (2016) as follows:</div><div><br></div><div>'The model also includes tidal forcing for the 16 most significant components that are applied as additional atmospheric pressure forcing (A. Chaudhuri 2014, personal communication).'</div><div><br></div><div>Rocha, C. B., Chereskin, T. K., Gille, S. T., & Menemenlis, D. (2016). Mesoscale to Submesoscale Wavenumber Spectra in Drake Passage. Journal of Physical Oceanography. 46(2), 601-620. https://doi.org/https://doi.org/10.1175/JPO-D-15-0087.1</div><div><br></div><div>Then, I read the 'data.exf' of LLC4320 at http://mitgcm.org/viewvc/MITgcm/MITgcm_contrib/llc_hires.</div><div><br></div><div>The 'data.exf' of LLC4320 shows some information as follows:</div><div><br></div><div>‘apressurefile = 'EOG_pres_tide',’</div><div><br></div><div>It looks like the tides are prescribed by the atmospheric pressure forcing files of 'EOG_pres_tide'.</div><div><br></div><div>I have not found more documentation of the tidal forcing descriptions of LLC4320 from http://mitgcm.org/viewvc/MITgcm/MITgcm_contrib/llc_hires</div><div><br></div><div>So, I have the following question.</div><div><br></div><div>1) Where can I get the tidal forcing data like‘EOG_pres_tide’used in LLC4320?</div><div><br></div><div>2) If I have the atmospheric pressure forcing fields with tidal forcing, can the tidal forcing be included by directly applying the atmospheric pressure forcing to the model with the 'data.exf'?</div><div><br></div><div>3) Is there anything else I should care about when I use the atmospheric pressure forcing to included tides?</div><div><br></div><div>Any comments or suggestions are warmly appreciated.</div><div><br></div><div>Cheers</div><div><br></div><div>Chengyan</div></div><div></div>_______________________________________________<br>MITgcm-support mailing list<br>MITgcm-support@mitgcm.org<br>http://mailman.mitgcm.org/mailman/listinfo/mitgcm-support<br></div></blockquote></div><br></div></body></html>