Our everyday lives are shaped by the ever-shifting turbulent winds of the atmospheric surface layer (ASL), the lowest ~100 m of the atmosphere. Step outside on a windy day and you will immediately feel the variability of wind gusts, some of which may dissipate in a few seconds while others might persist for several minutes. These time-varying flows strongly influence engineering systems and infrastructure in the ASL, including wind farms, drones, and cities, in ways that many existing steady-state models cannot predict. In this talk, I will describe several approaches for capturing the effects of unsteady flows on systems and technologies operating in the atmospheric surface layer. First, I will

present theoretical models and experimental measurements that demonstrate how wind turbines and wind farms can leverage streamwise unsteady flows to generate more power than their counterparts in steady flow. Then, I will discuss my lab’s ongoing efforts to develop cost-effective, field-deployable methods for uncovering unsteady dynamics in real-world ASL turbulence, including large-scale 3D Lagrangian particle tracking and low-cost sensor networks for measuring wind variations at city-block to neighborhood scales. This collection of measurement and modeling methods highlights the central role that unsteady flows can play in addressing societal challenges at the intersection of energy, climate, and human flourishing.