Tyndall Wave Climate Modelling

Wave Modelling for the Tyndall Coastal Simulator Project

A key goal of the Coastal Research Programme of Phase 2 of the Tyndall Centre for Climate Change Research is the development of accessible and useful integrated assessment methodologies for coastal areas, which is termed 'The Coastal Simulator'. In addition to advancing the state-of-the-art in integrated assessment, an explicit goal is to support the development of Shoreline Management Plans (SMPs) in the UK involving stakeholders such as the Environment Agency and their partners. SMPs are currently at a key stage with most now being updated for the first time. These SMPs need to be technically robust, integrating flood risk and coastal erosion in the context of climate change, spatial planning, habitat protection and the need for stakeholder engagement. The coastal simulator is designed to address these complex questions and provides information on the possible future states of the coast under a range of climate and socio-economic futures and shoreline management options. Currently, it is mainly focused on cell 3 (East Anglia) and sub-cell 3b, in particular, but the method is designed to be generic both in the UK, and more widely.

Wave climate modelling is being carried out by POL within the Coastal Simulator Project, funded by the Tyndall Centre for Climate Change Research. The wave model which has been used is the ProWAM model, a modified version of the WAM cycle 4 3rd generation wave model. This model includes wave generation by wind, nonlinear wave-wave interactions and dissipation processes including white-capping and bottom friction. The shallow water version is being applied over the NW European continental shelf on a 1/6° longitude by 1/9° latitude (~12km) grid, driven by winds from the Hadley Centre regional atmospheric model. This model is referred to as CS3. The boundary conditions for the model are taken from a 1° by 1° deep-water wave model of the whole Atlantic, using the same model code, forced by global coupled climate model winds. This allows even occasional swell events generated in the Southern Ocean during the northern hemisphere summer to propagate onto the continental shelf. Although swell from the North Atlantic does not have much effect on North Sea coasts, this could be important for applications in SW England, for example. Three scenarios from UKCIP02 (present-day, A2 and B2) and three from UKCIP08 (selected from a 17-member ensemble) are being modelled, generating 30-year time-slices in each case to provide wave climatologies under a range of climate change scenarios. Output from the CS3 model is generated at various locations including the area which provides boundary conditions for the coastal simulator prototype for cell 3b.

First results from the Atlantic model are being assessed for statistical agreement with the present-day wave climate, developing appropriate methodologies for statistical comparisons.