Near-surface physics and bio/physics

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The ocean and the atmosphere link together at the water surface. At small scales, winds produce waves, the sun provides heat and light, gases diffuse upwards and downwards, and deeper motions bring water up to and away from the surface. I would like to learn more about what happens in and near this thin skin, and try to use this information to understand other fundamental processes of oceanography. One research direction is based on the observation that to the eye (and in light winds), water often looks different in different places, sometimes smooth and shiny, sometimes dark and rough. These differences are sometimes caused by waves and turbulence internal to the flow (i.e. underneath the surface). Observing the surface and its changes over a period of hours can therefore give clues about what is happening below. These observations can be quantified using digital time-lapse imaging, a technique I have been developing for some time, in combination with more traditional measurements. I would like to further develop the imaging technique and use it to study a variety of nonlinear wave processes. In addition to explaining the visible features of the ocean surface, and advancing a fascinating branch of fluid mechanics, a better understanding of internal waves and stratified flows will be important in improving the capabilities of fine-resolution ocean and atmosphere models. A second research direction involves exploring the possibilities of making complex measurements of surface properties using inline systems mounted on ferries. By measuring one or more dissolved gases as well as standard parameters it may be possible to monitor biological activity in the upper ocean on scales of days to seasons. Understanding the variability of production is important in understanding the air/sea fluxes of CO2 (which in turn govern climate), and developing such applications for ferries may have significant impact as many such systems are currently in operation or proposed. Several possible technologies will be investigated to identify their possibilities.