[MITgcm-support] How to include tides by the atmospheric pressure like the tidal forcing in LLC4320

[whale]

Dear MITgcm users


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.


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.


The tidal forcing of LLC4320 is documented by Rocha et al. (2016) as follows:


'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).'


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


Then, I read the 'data.exf' of LLC4320 at http://mitgcm.org/viewvc/MITgcm/MITgcm_contrib/llc_hires.


The 'data.exf' of LLC4320 shows some information as follows:


‘apressurefile     = 'EOG_pres_tide',’


It looks like the tides are prescribed by the atmospheric pressure forcing files of 'EOG_pres_tide'.


I have not found more documentation of the tidal forcing descriptions of LLC4320 from http://mitgcm.org/viewvc/MITgcm/MITgcm_contrib/llc_hires


So, I have the following question.


1) Where can I get the tidal forcing data like‘EOG_pres_tide’used in LLC4320?


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'?


3) Is there anything else I should care about when I use the atmospheric pressure forcing to included tides?


Any comments or suggestions are warmly appreciated.


Cheers


Chengyan
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.mitgcm.org/pipermail/mitgcm-support/attachments/20241129/adeaf126/attachment.html>