Vertical coordinate nomenclature

[Diego_Pereiro]

Dear users,

Could you please let me know what's the difference between "S-coordinate" and "σ-coordinate"? It looks to me that both terms are used rather interchangeably in the literature. Perhaps they are used to highlight the difference between rigid-lid and free-surface ocean models, aren't they?

Could you please clarify this point?

Thank you in advance

Best regards

[jcwarner]

https://www.myroms.org/wiki/Vertical_S-coordinate