Mesoscale Air-Sea Interactions Observed by Autonomous Platforms During ATOMIC

Abstract:

A fleet of autonomous platforms observed air-sea interaction in the tradewind region of the tropical Atlantic Ocean during the ATOMIC field campaign (Jan-Feb 2020). Distributed measurements from multiple platforms sampled near-surface quantities and waves across mesoscale and submesoscale gradients in both the ocean and atmosphere. Two Wave Glider autonomous surface vehicles made repeated transects across ocean surface gradients, and six SWIFTs drifted on either side of the gradients. Preliminary results focus on two processes: 1) changes in surface wave slope caused by interaction of the tradewinds with mesoscale ocean currents, including increases in atmospheric wind stress when currents oppose waves, and 2) changes in air-sea heat, moisture, and buoyancy fluxes across sea surface temperature fronts, including larger fluxes when air-sea temperature and humidity differences are larger. These processes are evaluated in a series of case studies focusing on specific ocean mesoscale features, as well as over the entire two-month dataset.