@article{fdi:010077471, title = {{B}rinkman volume penalization for bathymetry in three-dimensional ocean models}, author = {{D}ebreu, {L}. and {K}evlahan, {N}. {K}. {R}. and {M}archesiello, {P}atrick}, editor = {}, language = {{ENG}}, abstract = {{A}ccurate and stable implementation of bathymetry boundary conditions remains a challenging problem. {T}he dynamics of ocean flow often depend sensitively on satisfying bathymetry boundary conditions and correctly representing their complex geometry. {G}eneralized (e.g. sigma) terrain-following coordinates are often used in ocean models, but they require smoothing the bathymetry to reduce pressure gradient errors ({M}ellor a al., 1994). {G}eopotential z-coordinates are a common alternative that avoid pressure gradient and numerical diapycnal diffusion errors, but they generate spurious flow due to their "staircase" geometry. {W}e introduce a new {B}rinkman volume penalization to approximate the no-slip boundary condition and complex geometry of bathymetry in ocean models. {T}his approach corrects the staircase effect of z-coordinates, does not introduce any new stability constraints on the geometry of the bathymetry and is easy to implement in an existing ocean model. {T}he porosity parameter allows modelling subgrid scale details of the geometry. {W}e illustrate the penalization and confirm its accuracy by applying it to three standard test flows: upwelling over a sloping bottom, resting state over a seamount and internal fides over highly peaked bathymetry features. {I}n future work we will explore applying the penalization to more realistic bathymetry configurations, and moving boundaries such as melting/freezing ice shelves.}, keywords = {{A}lgorithms ; {B}athymetry ; {B}ottom topography ; {C}omputation ; {O}cean modelling ; {P}enalization}, booktitle = {}, journal = {{O}cean {M}odelling}, volume = {145}, numero = {}, pages = {101530 [13 ]}, ISSN = {1463-5003}, year = {2020}, DOI = {10.1016/j.ocemod.2019.101530}, URL = {https://www.documentation.ird.fr/hor/fdi:010077471}, }