Structured-grid ocean models facilitate downscaling in the northeast Pacific, particularly for operational regional modelling and ocean forecasting in coastal British Columbia (BC), Canada. However, the complex oceanography and rugged coastal geography of BC pose well-known challenges for such models. In this study, we apply Adaptive Grid Refinement in Fortran (AGRIF) two-way nesting within the Nucleus for European Modelling o...

An adjoint-free four-dimensional variational (a4dVar) data assimilation (DA) is implemented in an operational ocean forecast system based on an eddy-resolving ocean general circulation model for the Northwestern Pacific. Validation of the system against independent observations demonstrates that fitting the model to time-dependent satellite altimetry during a 10-day DA window leads to substantial skill improvements in the succ...

A regional ocean ensemble simulation with slightly different initial conditions demonstrates that internal variability is formed (not only) in the Bohai and Yellow Sea. In this paper, we analyze the relationship between the internal variability and the baroclinic instability, (represented by the Eady predicted theoretical diffusivity $${K}_{t}$$ K t ; the larger the $${K}_{t}$$ K t , the stronger the baroclinic instability lev...

In July 2020, a stationary atmospheric front over Japan caused persistent, nearly continuous rain for most of the month that resulted in new historical highest rainfall records in several areas and caused serious river floods, landslides, and debris-flow events. An existing hindcast and forecast ocean circulation model that includes climatological discharge information of major rivers failed to represent the extreme river disc...