Ken Melville: The Use of Quantitative Imaging and Optical Techniques in Air-Sea Interaction: In situ and Airborne Experiments

Air-sea interaction plays a vital role in modulating weather and climate from global scales down to scales of the smallest surface waves. Ultimately, the bulk parameterization of air-sea fluxes in coupled atmosphere-ocean models depends on small scale processes. In this talk I will present results of ongoing air-sea interaction research at Scripps that uses both traditional atmospheric measurements of heat flux along with infrared imaging of the sea surface to study wave-modulated heat flux and surface turbulence. These measurements were made off the Scripps Pier and from R/P FLIP off the coast of California. A second set of experiments was undertaken in the Gulf of Tehuantepec, on the Pacific coast of Mexico, which is well known for the regular occurrence of high winds in winter which blow through the mountain gap at the head of the gulf out over the Pacific. In February 2004, we conducted a 4-week campaign of airborne measurements of the development of the wave field and wind field with fetch out to approximately 500 km offshore. The primary aim of the experiment was to measure the coupled development of the wave field and wind field, including the statistics of surface wave breaking for an improved understanding of the dissipation of surface waves and their role in air-sea fluxes. We used the NSF/NCAR C130 with its standard suite of meteorological measurements, GPS dropsondes and AXBTs, along with the NASA Airborne Terrain Mapper (ATM) used as a scanning LIDAR for surface wave measurement, and a video imaging package for measuring whitecaps. I will present an overview of the experiment and the results so far pertaining to the evolution of the surface wave field, wave breaking and extreme wave statistics.

Ken Melville is professor at the Scripps Institution of Oceanography, University of California and is an international expert on air-sea interaction.