Effects of Vegetation and Topography on the Boundary Layer Structure above the Amazon Forest
Effects of Vegetation and Topography on the Boundary Layer Structure above the Amazon Forest
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DOI：
10.1175/jas-d-20-0063.1
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发表时间：
2020-08-01
影响因子：
3.1
通讯作者：
de Araujo, Alessandro C.
中科院分区：
文献类型：
--
作者：
Chamecki, Marcelo;Freire, Livia S.;de Araujo, Alessandro C.
从两个实地活动在亚马逊森林的观测数据被用来研究森林上方的湍流的垂直结构。使用减少的湍流动能（TKE）预算及其相关的二维相空间进行分析。结果表明，存在两个区域内的粗糙子层中的TKE预算不能解释的典型的平坦地形TKE预算在树冠粗糙子层或在对流ABL的下部。数据分析还表明，偏离水平均匀性有很大的贡献TKE预算。LES的模型冠层在理想化的地形的结果呈现出类似的功能，导致的结论是，地形引起的流畸变是负责观察到的功能在theTKE预算。这些结果支持了亚马逊森林上方的边界层受到下方平缓地形的强烈影响的结论。
Observational data from two field campaigns in the Amazon forest were used to study the vertical structure of turbulence above the forest. The analysis was performed using the reduced turbulent kinetic energy (TKE) budget and its associated two-dimensional phase space. Results revealed the existence of two regions within the roughness sublayer in which the TKE budget cannot be explained by the canonical flat-terrain TKE budgets in the canopy roughness sublayer or in the lower portion of the convective ABL. Data analysis also suggested that deviations from horizontal homogeneity have a large contribution to the TKE budget. Results from LES of a model canopy over idealized topography presented similar features, leading to the conclusion that flow distortions caused by topography are responsible for the observed features in theTKEbudget. These results support the conclusion that the boundary layer above the Amazon forest is strongly impacted by the gentle topography underneath.