This application covers the needs for computational geophysical fluid dynamics and ocean modelling at the coastal oceanography group at Department of Marine Sciences at University of Gothenburg. Physical oceanography is a discipline that is a traditional user of supercomputing resources, as it involves solving large partial differential equation systems. This application is a direct continuation of several SNIC/NAISS projects. The project will include several oceanographic applications ranging from 10 m scales to 100 km scales. Thus, different models will be used for different projects, and will be described in this application. All applications are based on well-developed codes with a large international user groups, all applications are already installed and run on the supercomputer Tetralith. All applications have been developed with HPC resources in mind. More specific we consider investigations on: • Tidal energy is an emerging sustainable power source. In order to increase the extractable amount the power plants need to be arranged in farms as for wind power (PhD work). Here the turbulence in a tidal current and how it impact on Deep Green, which is a tidal energy extracting device developed by Swedish company Minesto. The wake and turbulence generated by Deep Green is a vital part of the project, and outstanding question is how dense packed farms of Deep Green that is optimal. Extractable power for different farm configurations will also be studied. This is a continuation on a previous large-scale project. • Regional oceanography on the Swedish west coast and how particles such as plastic and plankton are transported by currents. The transport of harmful substances by shipping is also investigated. • The dispersion of Methane is investigated using a high-resolution setup (450 m resolution) for the Baltic Sea. The model is forced by perturbations in wind speed to get a model ensemble to quantify uncertainties in dispersion fields. • Resources will also be allocated depending on the needs to Master students (2 students) that would carry out a short internship or thesis during the project period. Total request: 30TB storage and allowance for 2,500,000 files.