The numerics of hydrostatic structured-grid coastal ocean models: State of the art and future perspectives. (May 2018)

• Record Type: Journal Article
• Authors: Klingbeil, Knut; Lemarié, Florian; Debreu, Laurent; Burchard, Hans
• Is Part Of: Ocean modelling. Volume 125(2018)
• Page Start: 80
• Page End: 105
• Publication Date: 2018-05
• Subjects: Coastal ocean models -- Hydrostatic models -- Adaptive coordinates -- Mode-splitting -- Drying & flooding -- Two-way nesting; Oceanography -- Periodicals; Océanographie -- Périodiques; Oceanography; Periodicals; 551.46
• DOI: 10.1016/j.ocemod.2018.01.007
• Languages: English
• ISSNs: 1463-5003

Abstract

Highlights: Numerical methods of coastal ocean models differ from large scale models. Characteristics of coastal ocean dynamics determine specific model features. Review of state of the art numerical techniques of coastal ocean models. Overview over most relevant existing structured-grid coastal ocean models. Abstract: The state of the art of the numerics of hydrostatic structured-grid coastal ocean models is reviewed here. First, some fundamental differences in the hydrodynamics of the coastal ocean, such as the large surface elevation variation compared to the mean water depth, are contrasted against large scale ocean dynamics. Then the hydrodynamic equations as they are used in coastal ocean models as well as in large scale ocean models are presented, including parameterisations for turbulent transports. As steps towards discretisation, coordinate transformations and spatial discretisations based on a finite-volume approach are discussed with focus on the specific requirements for coastal ocean models. As in large scale ocean models, splitting of internal and external modes is essential also for coastal ocean models, but specific care is needed when drying & flooding of intertidal flats is included. As one obvious characteristic of coastal ocean models, open boundaries occur and need to be treated in a way that correct model forcing from outside is transmitted to the model domain without reflecting waves from the inside. Here, also new developments in two-way nesting are presented. Single processes such as internal inertia-gravity waves, advection and turbulence closure models are discussed with focus on the coastal scales. Some overview on existing hydrostatic structured-grid coastal ocean models is given, including their extensions towards non-hydrostatic models. Finally, an outlook on future perspectives is made.