The dynamics and thermodynamics of the sea surface
Convection at an evaporating surface, as seen in infra-red
The ocean-atmosphere interface is a highly complex and extremely important part of the climate system. The dynamics and thermodynamics of the sea surface govern fluxes of heat, momentum and CO2 between the atmosphere and the ocean. Thus, the properties of the sea surface play a vital role in climate and weather. In this project we use theory, models and laboratory experiments to investigate the dynamics and thermodynamics of the sea surface, including:
The energy balance at the sea surface. Heat fluxes at the surface include incoming longwave (sometimes called infra-red) radiation from the sky, outgoing longwave from the surface, shortwave radiation from the sun, sensible heating from the atmosphere, and latent heating due to evaporation, and heat transfers into the ocean interior via mixing. Combined, these fluxes control the surface temperature of the ocean, which in turn controls the air temperature in coastal areas. Understanding these fluxes and how they may change in a changing climate is thus of great importance.
The dynamics of the surface. This project addresses the question of how stress is transmitted from the air to the ocean below, as winds blow across the ocean surface. We seek to improve the way this interaction is represented in global ocean and climate models through fundamental experiments in the GFD Lab.
The movie below shows the impact of a sudden air gust applied to an evaporating water surface in the GFD Lab (whiter = hotter). The surface is naturally cooler than the interior of the fluid due to evaporative heat loss. The air gust drives upwelling, bringing warmer water to the surface, which then rapidly cools.