Inverse Energy Cascades in the Boundary Layer During Strong Winds Based on Doppler Lidar

Abstract

Inverse energy cascade (IEC), where energy moves from small to large eddies, has been debated, with limited observational evidence. This study used 19 months of Doppler Lidar data from Qingdao, China, to examine IEC associated with gusts. We found IECs occurred 15% of the time at 50 m height. When near-surface wind speeds exceeded 11 m·s⁻¹, IEC frequency and intensity increased, indicating that strong winds are a critical driver of IEC. This study suggests that the reduction in the drag coefficient under high wind conditions may generate IEC and gusts, consequently influencing energy transfer throughout the boundary layer and lower troposphere. Analysis using the four-quadrant model revealed IECs are linked to changes in momentum from ejections and inward interactions, even in weak background fields. The study supports that IECs are more prevalent and highlights their role in the lower atmosphere, contributing to an improved understanding of land-atmosphere coupling.