SWOT-UK: The UK contribution to validating SWOT in the Bristol Channel and River Severn, with application to coastal and river management

The Surface Water and Ocean Topography (SWOT) mission will provide for the first time from space two-dimensional high-resolution maps of surface water levels
globally over ocean and inland waters. If SWOT meets its performance targets, it will represent a major milestone in our ability to observe, study and understand the nature and evolution of the Earth’s marine and land surface water systems, globally. The UK Space Agency invested in SWOT jointly with the US NASA, French CNES and Canadian Space Agency to enable the implementation and launch of this mission. The SWOT-UK project proposes a comprehensive programme of campaigns and multidisciplinary research centred on the Bristol Channel and River Severn region as the UK contribution to the international SWOT Science Team validation efforts. In accordance with the requirements of the NERC/UKSA SWOT CalVal call, SWOT-UK takes an open and inclusive approach, putting special emphasis on disseminating value-added SWOT validation datasets and engaging with the wider UK science and stakeholder communities to raise awareness of the SWOT capabilities. Accordingly, the objectives of SWOT-UK are:

• To assemble a large dataset of quality-controlled ground-truth and satellite data of water level, slope and river discharge over the Bristol Channel/River Severn region.
•  To carry out a targeted campaign of airborne and shipborne surveys during the SWOT 90-days daily repeat cal-val mission phase to complement existing observations.
• To investigate critical aspects of SWOT instrument and mission performance using pre-launch and campaign data to determine the quality of SWOT data in coastal and estuarine settings.
• To use SWOT data for novel validation of 2D ocean, wave and hydrodynamic models, and their ability to resolve marine-fluvial interactions and water level spatial variability.
• To represent the UK within the international SWOT Science Team, interact with SWOT and the UKSA, and engage with key flood forecasting and coastal management stakeholders and the wider UK community to disseminate findings and quality-controlled datasets.