USAP-DC

The coupled air-sea dynamics of the Southern Ocean play a critical role in the ocean?s transport and storage of heat and carbon dioxide and the response of these processes to climate change. This project advances our capability to observe air-sea dynamics under winds through a 6-month deployment of a wave glider. The wave glider has been adequately demonstrated as a robust high-endurance platform for open-ocean work and has begun to demonstrate its capability for research-quality measurements. This project will advance that capability by increasing our understanding of vehicle and sensor performance and suitability for measuring air?sea fluxes of momentum, moisture, and heat. Simultaneously, the vehicle will be used to study critical scientific questions on air-sea interactions. The project will include graduate and undergraduate student training and outreach activities through local schools, the Seattle Aquarium, and the Pacific Science Center. The main research topics addressed in this project are the spatial structure of winds and surface properties in the Southern Ocean, the influence of surface wave Stokes drift on Ekman transport in the upper ocean, wave modulation of wind stress, near-inertial wind energy input into the ocean, and the coupling between winds and sea surface temperature. The observations will be taken by a Liquid Robotics Wave Glider SV3 autonomous surface vehicle instrumented for measurements of surface waves, temperature and salinity, upper-ocean currents, barometric pressure, and winds. Deployment and recovery will exploit planned cruises maintaining the Ocean Observatories Initiative Southern Ocean array and re-supplying the US Antarctic Program's Palmer Station. The sampling plan consists of (1) three months near the Ocean Observatories Initiative air-sea interactions buoy to study spatial structure and allow cross-calibration of the various sensors and their responses to vehicle heading and wind and wave conditions; (2) two months conducting a downstream grid survey across the Antarctic Circumpolar Current towards Drake Passage; and (3) a month-long timeseries in southern Drake Passage in the weak-current region between the Polar Front and the Southern ACC Front before recovery from the R/V Laurence M. Gould.