Vertical structure of conventionally neutral atmospheric boundary layers

Conventionally neutral atmospheric boundary layers (ABLs) are frequently encountered in nature, and their flow dynamics affect the transfer of momentum, heat, and humidity in the atmosphere. Therefore, insight into the flow structure in conventionally neutral ABLs is necessary to further improvemodels for long-term weather and climate forecast, while it provides further insight for atmospheric applications like the wind industry. The structure of conventionally neutral ABLs is complicated due to the coexistence of shear- and buoyancy-generated turbulence, and therefore analytical descriptions have been limited to the mean wind speed. Here we introduce an innovative model based on the Ekman equations and the basis function of the universal potential temperature flux profile that allows one to describe the vertical profiles of the horizontal components of wind and shear stress and hence capture features like the wind veer profile. Our formulation in terms of departure from the geostrophic wind allows us to describe the profiles as a function of one control parameter, although the description of wind speed profile still needs two. We find excellent agreement between analytical predictions, high-fidelity simulations, and fieldmeasurement campaigns. These findings advance the fundamental understanding of the ABL structures and atmospheric turbulence.

Automated summary

Studying the flow structure in conventionally neutral atmospheric boundary layers is important for improving weather and climate forecast models, as well as for applications in the wind industry. This research introduces an innovative model based on the Ekman equations and the universal potential temperature flux profile, which accurately describes the vertical profiles of wind speed and shear stress, capturing features like wind veer profiles.