Tides and storm-surge dynamics are important contributions to extreme events and global climate processes, responsible for significant sea surface height fluctuations in nearshore regions as well as mixing processes in deep oceans and coastal estuaries. The action of the tidal cycle and storm-driven surge impacts can combine to generate substantial flooding and inundation in low lying coastal regions, posing significant risk to communities and infrastructure. Using a newly developed barotropic configuration of MPAS-Ocean, in which depth-averaged dynamics are solved using a simplified, single-layer approach, the Integrated Coastal Modeling (ICoM) team are extending E3SM capabilities to capture these extreme events. A range of new model features and configurations have been developed, enabling tidal fluctuations to be modeled throughout the global ocean and coastal zone, storm-surge and inundation effects to be simulated down to sub-kilometer scales, and the efficiency of the model to be improved using newly developed local time-stepping techniques that concentrate computational effort according to the resolution of coastally-refined unstructured meshes.
