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Abstract Advances in uncrewed surface vehicles enable expanded observations in the critically undersampled Southern Ocean—a region vital for global heat uptake. Using data from three Saildrone missions that sampled the Pacific sector of the Southern Ocean in both summer and winter, we evaluate processes and spatiotemporal scales of decorrelation that drive sensible heat fluxes. Enhanced heat flux variability is primarily linked to synoptic‐scale southwesterly winds, with decorrelation scales of 50 km and 10 hr, consistent across seasons. These scales are influenced by both atmospheric forcing and oceanic variability, with sharp sea surface temperature changes occasionally driving pronounced shifts in sensible heat flux. Our results extend the observed relationship between wind direction and heat loss across the entire Pacific sector of the Southern Ocean, previously limited to three locations. Our data sets reveal over 8,000 temperature fronts ranging from <1 km to >20 km in width. These fine‐scale ocean processes contribute to the heat flux variability 35% of the time. While wind‐related variability dominates sensible heat flux changes across the smallest fronts, the ocean's role becomes increasingly significant with wider ocean fronts, particularly those over 4 km in width. However, due to their larger abundance, the total change of sensible heat flux over smaller (1 km) fronts is an order of magnitude greater than larger fronts (>4 km). These results highlight the role of fine‐scale atmosphere‐ocean interactions relating to heat flux variability in the Southern Ocean, offering valuable insights for enhancing flux estimates in this critical region. 

Abstract Two decades of high-resolution satellite observations and climate modeling studies have indicated strong ocean–atmosphere coupled feedback mediated by ocean mesoscale processes, including semipermanent and meandrous SST fronts, mesoscale eddies, and filaments. The air–sea exchanges in latent heat, sensible heat, momentum, and carbon dioxide associated with this so-called mesoscale air–sea interaction are robust near the major western boundary currents, Southern Ocean fronts, and equatorial and coastal upwelling zones, but they are also ubiquitous over the global oceans wherever ocean mesoscale processes are active. Current theories, informed by rapidly advancing observational and modeling capabilities, have established the importance of mesoscale and frontal-scale air–sea interaction processes for understanding large-scale ocean circulation, biogeochemistry, and weather and climate variability. However, numerous challenges remain to accurately diagnose, observe, and simulate mesoscale air–sea interaction to quantify its impacts on large-scale processes. This article provides a comprehensive review of key aspects pertinent to mesoscale air–sea interaction, synthesizes current understanding with remaining gaps and uncertainties, and provides recommendations on theoretical, observational, and modeling strategies for future air–sea interaction research. Significance StatementRecent high-resolution satellite observations and climate models have shown a significant impact of coupled ocean–atmosphere interactions mediated by small-scale (mesoscale) ocean processes, including ocean eddies and fronts, on Earth’s climate. Ocean mesoscale-induced spatial temperature and current variability modulate the air–sea exchanges in heat, momentum, and mass (e.g., gases such as water vapor and carbon dioxide), altering coupled boundary layer processes. Studies suggest that skillful simulations and predictions of ocean circulation, biogeochemistry, and weather events and climate variability depend on accurate representation of the eddy-mediated air–sea interaction. However, numerous challenges remain in accurately diagnosing, observing, and simulating mesoscale air–sea interaction to quantify its large-scale impacts. This article synthesizes the latest understanding of mesoscale air–sea interaction, identifies remaining gaps and uncertainties, and provides recommendations on strategies for future ocean–weather–climate research.