h-NUMO: A high-performance discontinuous-Galerkin code for hydrostatic ocean modelling

h-NUMO is an isopycnal ocean circulation model that uses barotropic–baroclinic splitting to separate fast and slow motions into coupled subsystems. h-NUMO is implemented in the Galerkin Numerical Modeling Environment (GNUME) framework, which supports arbitrary-order polynomial bases and both continuous and discontinuous Galerkin methods. The model's accuracy and performance are assessed through a series of numerical experiments, including a double-gyre circulation test case, with results benchmarked against those from the HYCOM model. A detailed description of the model and its numerical discretization, as well as model performance, is provided in Gahounzo et al. (2026).