Field Observation Site for Air-Sea Interactions in Tropical Cyclones

Accurate predictions of winds, waves and currents within extreme tropical cyclones are critical for shipping, offshore oil and gas, ports and harbours, coastal erosion, tourism and fishing. The paper will describe a unique field observation programme intended to gather in situ data about air-sea interactions in tropical cyclones. The site has been established on the Woodside-operated North Rankin Complex, an offshore gas production facility located off the north-west coast of Western Australia. The facility is multi-purpose. It will assist Woodside to manage platform operations during the cyclone season and to make advances in the estimate of extreme wave crest heights for platform loading while enabling academic researchers to measure air-sea interactions. Concurrent measurements are conducted in the atmospheric boundary layer, on the ocean surface and below the surface all the way to the bottom at 120 m depth. The measurements include fluxes of momentum and energy across the air-sea interface, spray production, directional wave spectra up to high wavenumbers, and will allow us to close the balance of the air-sea exchanges for the first time in extreme field conditions.