The Rough Ocean

Albert Einstein said "everything should be made as simple as possible, but no simpler". This applies well to many theories underpinning physical oceanography, the study of the ocean dynamics. People have assumed, for example, that the ocean has a constant density, is forced by constant winds and has a flat bottom. These assumptions have been revisited in turn, leading to alterations in our understanding. Arguably though, the flat bottom concept remains lodged in our perception. We use flat bottom functions to describe the vertical structure of currents, discuss the depth-averaged response, and compare satellite observations with flat bottom wave modes. But nowhere is the bottom flat, and there is mounting evidence that bottom topography affects currents all the way to the surface. In The Rough Ocean, physical oceanographers and marine geologists will work together to study specific flow-topography interactions. These include how topography affects the Gulf Stream and "planetary waves", with scales of hundreds to thousands of kilometers, but also submarine topographic waves, which are often invisible at the surface but may contribute significantly to the oceanic energy balance. The results will improve our future analyses, but also how we represent topography in climate models, which cannot resolve topographic interactions at small scales.

Many theories of ocean circulation neglect bottom topography. Recent observational and theoretical evidence suggests to the contrary that topography exerts a dominating influence on the vertical structure of time-varying oceanic flows. The proposed work seeks to bridge the gap between oceanographic theory, observations and full complexity numerical models by examining interactions between specific flows and topography, both idealized and realistic. The project also aims to strengthen interactions between physical oceanography and marine geology, two disciplines which often have been independent. Results from The Rough Ocean project will help improve the use of satellite-derived ocean data, aid the interpretation and running of climate models, improve ocean prediction and open possibilities for future inter-disciplinary work.