UAS and Distributed Temperature Sensing Reveal Previously Unseen Atmospheric Processes

Abstract:

The frontier of atmospheric boundary layer research lies in times and places of complexity. Transitions between atmospheric states, buoyant flows over complex terrain, and times with only weak forcing mechanisms all have rich physical expressions of atmospheric flow that are not fully understood. These motions often span a large range of scales and are nonstationary. Traditional atmospheric measurement approaches are inadequate in these situations as they do not have the data density or the physical extent to capture the full range of motions. An unmanned aerial system (UAS) is used to lift distributed temperature sensing (DTS) technologies to observe the early morning transition from stable to unstably stratified conditions. The UAS/DTS combination yielded observations of temperature and humidity in the lower atmosphere with never-seen-before resolution and extent. The data reveal a complex interplay of motions that occur during the morning transition that ultimately results in the propagation and growth of unstable wave modes. The observations have given new insight into the appropriate scaling variables for the morning transition time.