Unique Atmospheric Boundary Layer Structures Driven by Lake Effects

Lakes are an integral part of regional energy and water cycling regime. They influence the structure of the Atmospheric Boundary Layer (ABL), where most of land-atmosphere interactions take place, through regional heat exchange, wind patterns and moisture transport. As a key indicator of the ABL structural variations, its height (ABLH) can intuitively show lake effects on the atmosphere. Despite several regional evidence, global impact of lakes on ABLH remains insufficiently understood. Here, we investigate the impact of large inland lakes (lake area > 500 km ² ) on the ABLH across different climatic zones. Our findings show clear spatial effects with lakes elevating the ABLH in adjacent regions (0-25km) through lake-land breezes, and moisture-driven instability. These effects are strongest in summer and autumn, which are the focus periods of this study. Above lake surfaces, the atmosphere tends to be more stratified due to strong thermal inertia that suppresses turbulent mixing. These effects weaken beyond 25km, where large-scale atmospheric processes dominate. In lake regions, temperature difference and sensible heat flux are the dominant positive drivers of ABLH, while relative humidity and surface pressure act to suppress it. During summer, thermal forcing is particularly strong, whereas in autumn, increasing influence from humidity and pressure contributes to enhanced atmospheric stability. In addition, these lake effects vary with latitude, elevation, and lake size. Thermal processes dominate at low latitudes and over large lakes, while dynamic and moisture processes become more important at higher latitudes and elevations. Better representation of lake-boundary layer coupling in models could improve weather and climate forecasts in lake-rich regions. Our results provide the first global perspective on how large lakes regulate ABLH and underscore the critical role of lake-atmosphere interactions in shaping regional weather patterns.