Aerodynamic resistance changes in the atmospheric surface layers (ASLs), such as coastal zones and rural–urban interface, complicate the transport processes. Their effect on ASL flows is investigated by the large-eddy simulation (LES) with the one-equation subgrid-scale model. The roughness elements at the bottom are explicitly resolved by sinusoidal wavy surfaces to examine the coupling between roughness sublayers (RSLs) and inertial sublayers (ISLs). In view of the increasing (decreasing) aerodynamics resistance after an abrupt surface transition, the flows decelerate (accelerate) and the momentum flux increases (decreases). The adjustments initiate at the RSLs during the development of the internal boundary layer (IBL) so the flows hardly establish self-similarity immediately after surface transitions. The evolving IBL illustrates the flow adaptation to the downstream (new) surface. Unlike those analytical solutions, the current LES unveils a slower IBL growth in the streamwise direction, demonstrating the importance of resolving RSLs explicitly. Besides, augmented turbulent diffusion is observed over the rougher surface. The gradual adjustment of higher-order moments along with developing IBL confirms that IBL is a physically significant length scale. The spatial behaviours of skewness and kurtosis, which suggest coherent events, are visualized across the surface discontinuity. The wall-normal distributions of energy spectra show that the energy-carrying turbulence shifts to higher frequency over the rougher surface. Small-scale turbulence motions are adjusted in ISL. Moreover, the shift is completed substantially on large-scale RSL turbulence, demonstrating the significance of RSLs.

大气表面层 (ASL) 中的空气动力阻力变化，例如沿海地区和城乡界面，使运输过程复杂化。它们对 ASL 流动的影响通过大涡模拟 (LES) 与一方程子网格尺度模型进行了研究。底部的粗糙度元素通过正弦波表面明确解析，以检查粗糙度子层 (RSL) 和惯性子层 (ISL) 之间的耦合。鉴于表面突然过渡后增加（减少）的空气动力学阻力，流动减速（加速）并且动量通量增加（减少）。在内部边界层 (IBL) 的发展过程中，在 RSL 处开始调整，因此在表面转变后，流动很难立即建立自相似性。不断发展的 IBL 说明了对下游（新）表面的流动适应。与那些解析解不同，当前的 LES 揭示了流向方向上较慢的 IBL 增长，证明了明确解析 RSL 的重要性。此外，在较粗糙的表面上观察到增强的湍流扩散。随着 IBL 的发展，高阶矩的逐渐调整证实了 IBL 是一个具有物理意义的长度尺度。偏度和峰度的空间行为表明相干事件，在整个表面不连续性上可视化。能谱的壁面正态分布表明，携带能量的湍流在较粗糙的表面上转移到更高的频率。在 ISL 中调整小尺度湍流运动。此外，在大规模 RSL 湍流上基本上完成了转变，