Stormy Atmospheres over Quiescent Waters: Dynamical Implications of Fine-scale Air-Sea Interaction

forthcoming

The atmosphere and ocean exhibit natural fluctuations at many scales. Compellingly, their responses to each other’s cues, felt through fluxes at the interface, may be taking place at much finer scales. At the air-sea interaction (ASI) submesoscale, ranging from about 200 m to 200 km, both air and water are filled with beautiful heterogeneous structure. Unraveling how such fine-scale structure drives air-sea exchange, leading to different dynamics in both fluids, is an emerging challenge for climate science. My ambition is to expose dynamical impacts and primary mechanisms of submesoscale interaction between atmospheric moist convection and tropical quiescent waters. With QUASI, I will use Earth’s stormiest and largest tropical lake as an ocean mixed-layer analog, avoiding the complexity of a deep wavy ocean. Lake Victoria offers the ideal field lab to study sensitive waters and strong atmospheric signals in the form of near-daily convective storms triggered by warm waters and mesoscale circulations. QUASI will realize a multi-sensor multi-buoy network on the lake to measure spatial, cross-interface, high-resolution observations of the near-surface atmosphere and water for over a year. The observations force ocean mixed-layer models to uncover important variability and inspire and inform advanced atmospheric large-eddy and storm-resolving simulations in uncoupled and coupled configurations. QUASI will identify key atmospheric drivers and scales of heterogeneity in air-sea fluxes, expose responses of surface water temperature and mixing, infer dynamical implications of treating water as a static homogeneous surface, and study the impact of submesoscale ASI on regional weather patterns and extremes. While inherently challenging, QUASI delivers rare cross-disciplinary evidence critical for advancing a new era of coupled high-resolution models needed to unravel surprising energy pathways in our climate system.