Understanding the processes that govern the mixing and transport of scalars within and above the Amazon Forest is of great importance for many environmental applications. The impact of atmospheric stability on the roughness sublayer (RSL) as well as the influence on it by the processes in the overlying atmosphere are investigated using measurements collected at the Atmospheric Tall Tower Observatory. Five different stabilities are defined according to the turbulent fluxes’ behaviour. Ejections dominate the transport in the RSL. In near neutral and unstable conditions coherent structures propagate up to 2–3 times the canopy height (h) and intermittently penetrate in the lowest part of the forest where sweeps drive the transport processes. In the unstable regime a weakening of the wind inflection at the canopy top and a transition to a convective regime above z = 2 h are observed. In stable conditions three regimes were defined characterised by a progressive lowering of the RSL and the weakening of the mixing-layer type coherent structures. In the ‘weakly stable’ regime the intense momentum and scalar fluxes appear driven by the coherent structures being able to penetrate inside the canopy intermittently coupling the flow above and within the forest. The ‘very stable’ regime is characterized by weak winds, a weakening of coherent structures and a decrease of the turbulent fluxes inhibited by buoyancy. The definition of a ‘super stable’ regime allowed the identification of a peculiar condition characterized by low-wind and weak coherent structures confined close to the canopy top and producing negligible transport. Submeso motions dominate the flow dynamics in this regime both above and inside the RSL. Multiresolution analysis highlights the ability of submeso motions to propagate inside the canopy and to modulate the exchange, particularly of scalars, fully driving the large positive CO₂ flux observed inside the forest in the super stable regime.

了解控制亚马逊森林内外标量混合和传输的过程对于许多环境应用非常重要。使用在大气高塔天文台收集的测量数据，研究了大气稳定性对粗糙度亚层 (RSL) 的影响以及上覆大气中的过程对其的影响。根据湍流的行为定义了五种不同的稳定性。弹射在 RSL 中占主导地位。在近中性和不稳定条件下，相干结构的传播高达冠层高度的 2-3 倍（h) 并间歇性地渗透到森林的最低部分，那里的清扫推动了运输过程。在不稳定状态下，树冠顶部的风转折减弱，并过渡到z以上的对流状态 = 2 小时观察到。在稳定条件下，定义了三种状态，其特征是 RSL 的逐渐降低和混合层型相干结构的减弱。在“弱稳定”状态下，强烈的动量和标量通量似乎是由能够穿透树冠内部的连贯结构驱动的，这些结构间歇性地耦合森林上方和内部的流动。“非常稳定”的状态的特点是风弱，连贯结构减弱和受浮力抑制的湍流减少。“超级稳定”状态的定义允许识别以低风和弱相干结构为特征的特殊条件，这些结构限制在树冠顶部附近并且产生可忽略不计的传输。Submeso 运动在 RSL 上方和内部都主导着该区域的流动动力学。₂在超稳定状态下在森林内观察到通量。