This study examines the geometric organization of near-wall turbulence structures in the Atmospheric Surface Layer (ASL) based on high-resolution, synchronized multipoint measurements from the Surface Layer Turbulence and Environmental Science Test (SLTEST) field campaign. Focusing on Reynolds shear stress and turbulent heat flux, we extract wall-normal length scales and inclination angles from two-point velocity–temperature correlations under a wide range of Monin–Obukhov stability conditions. Results show that, under unstable stratification, both the vertical extent and inclination of coherent structures increase systematically with decreasing atmospheric stability. These variations are well-described by distinct empirical logarithmic relations, reflecting the influence of buoyancy-driven turbulence production. In contrast, under weakly stable conditions, coherent structures are substantially suppressed and lose directional organization. Under neutral conditions, baseline length scales of the turbulent structures are recovered, in agreement with canonical ASL scaling. The observed dependence of structure geometry on stability underscores the critical role of thermal forcing in modulating momentum and scalar transport, and highlights the need to parameterize coherent structural features explicitly in surface-layer models.
Zhu et al. (Mon,) studied this question.