FOXSTORM · Feedbacks On eXtreme STorms by Ocean tuRbulent Mixing

I propose to use autonomous underwater ocean glider vehicles with a newly developed airborne deployment system to measure ocean turbulence in extreme storms, such as hurricanes, typhoons, and tropical storms. These will be the first vertically resolved measurements of ocean turbulence in extreme storms, and will lead to a new understanding and improved estimates of the oceanmixing that is responsible for setting upper ocean temperatures - a crucial and poorly constrained feedback on storm intensity.By combining the observations with turbulence-resolving large eddy simulations, performed on high performance computational clusters, a new observationally-constrained model of the ocean-storm mixing feedback will be constructed that fills a much needed gap in the coupling of extreme storms to the ocean. This is crucial since extreme storms are increasing in strength and frequency through climate change, and are leading to record damages and loss of life in coastal communities. Such measurements are only now possible, since my research team has played a major role in pioneering the use of microstructure turbulence measurements from autonomous underwater gliders, particularly in stormy conditions. The final outcomes of the project will consist of (i) an airborne deployment system for the study of extreme events using autonomous vehicles, (ii) the first observations of upper ocean turbulence and mixing in extreme storms, (iii) a sequence of turbulence-resolving numerical simulations that, together with the observations, will identify and quantify processes responsible for setting upper ocean heat fluxes and turbulent structure in extreme storms, and (iv) a new parameterisation for ocean mixing in extreme storms that quanties the ocean-storm feedback, and its implementation inthe forecasting model of the European Centre for Medium-range Weather Forecasts (ECMWF).