Observational case study revealing oceanic internal solitary waves modulating air-sea interactions in northern South China sea

Internal solitary waves (ISWs) are extreme oceanic dynamic processes that significantly modulate sea surface currents and roughness, but their roles in air-sea interactions are still poorly understood. Here, synchronous ship-board observations of the ocean interior, sea surface and near-surface air conditions in the northern South China Sea showed that, influenced by one ISW front, skin temperature, air temperature, and wind speed decreased by up to 0.9℃, 0.72℃, and 3.1 m·s^-1, respectively. Surface waves enhanced significantly over the strong convergence zone of the ISW front, which perturbed the sea surface and likely resulted in the decrease of skin temperature to bulk water temperature. Air-sea heat flux was estimated to decrease by up to ~ 50% therein. A satellite image acquired during the experiment period showed that ISW fronts occupied 13.4% of the area around the Dongsha Island. Those results suggest that ISWs could be a potentially relevant modulator of regional air-sea interactions.