Ocean Shelf-Edge Exchange
The edge of the coastal shelf represents a major boundary within the ocean system. The topography of the shelf edge constrains large scale ocean currents from crossing the shelf boundary and limits the connections between the two systems.
In the absence of exchanges associated with large scale currents, shelf ocean exchanges are driven by a variety of small scale physical processes that are profoundly influenced by topography around the boundary and meteorological forcing. These processes include internal tides, upwelling, sinking via cascading to deep water, eddies, filaments and storms.
The observation and modelling of these small scale net exchanges within a highly dynamic system represent a major challenge. We cannot currently describe the processes involved in these exchanges, how they interact and what controls them. Hence these processes are currently inadequately parameterised within ocean models.
Exchange of water between the oceans and the shelf seas has a considerable impact on the shelf seas and societal use of these seas, as well as impacting the open ocean. These exchanges affect:
- the export of carbon and contaminants to the deep seas;
- nutrient exchanges across the shelf break which fuel much of the productivity of shelf seas overall, and the high productivity and associated fisheries around the shelf edge;
- the regional climate via heat exchange; and
- large scale oceanographic processes via the exchange of freshwater.
Climate change has the potential to significantly change all of these processes.
The UK is surrounded by one of the world's major continental shelves which provide a series of key environmental services for the UK ranging from waste disposal, through renewable and non-renewable resources to recreation. Shelf edge exchange processes underpin the productivity of coastal seas on which we depend for most of our marine fisheries.
The shelf seas represent the Earth's second most valuable ecosystem and the most valuable marine ecosystem, hence more effective management of the coastal seas in the face of climate change is the key economic benefit of this research programme.
This programme will contribute to delivering NERC strategy and underpin much other current and planned future research on the shelf seas. It will contribute directly to delivering the climate system, Earth system science and technologies themes.
In addition, it will indirectly support the sustainable use of natural resources and biodiversity themes. This work will also help support other NERC research programmes including the Ice Sheet Stability and Arctic research programmes.
This research programme will also contribute to maintaining world leading UK research expertise in this area, and to building links to other research efforts developed by other agencies (Western Shelf Observatory) which will contribute to several Living With Environmental Change objectives.
The research will inform the development of several NERC themes and more widely to international programmes such as IMBER and LOICZ.
The overarching objective of the Ocean Shelf-Edge Exchange research programme is:
"To improve our fundamental understanding of shelf edge processes which influence the environmental conditions of coastal seas."
To deliver this objective, this programme will examine the fundamental physical processes of exchanges between the edge of the coastal shelf and the open ocean, and will improve understanding of shelf edge exchange processes in different shelf environments in order to allow these processes to be better incorporated into models.