Organized Turbulence over Forested Landscapes: Theoretical Basis for a Low-Dimensional Transport Model

0208258艾伯森了解森林景观与能量、水和碳的湍流通量之间的耦合的需要已经成为国家的优先事项，正如USGCRP的水和碳循环科学计划所证明的那样。 在这里，提出了一个概念模型来描述湍流输送的质量和能量之间的森林冠层和大气中的两个端元流类型：混合层（在茂密的植被）和粗糙壁边界层。 具有不同程度稀疏植被的区域被表示为两个端员制度的叠加。 首要目标是开发一个相似理论的树冠层（CSL）的运输，垂直运输现象的描述耦合高分辨率的表面功能（很容易观察到远程）和粗分辨率的大气场（观察和模拟）。 该项目的结构，以测试三个假设的基础上的概念模型。 重点是冠层形态和有组织的湍流运输之间的相互作用。 现场数据分析与大涡模拟（LES）相结合-数据提供现场条件的观察结果，LES提供受控边界条件下湍流演变结构的完整视图。 LES的结果将被用来确定基本的动力学和制定签名的相干结构，将用于指导随后的分析现场数据集。 湍流场的多尺度分解将与非线性时间序列分析工具配合使用，以便开始低维模型的开发。 这种方法将为研究生和博士后提供独特的培训经验。 PI将继续招聘/培训代表性不足的候选人。

0208258AlbertsonThe need to understand the coupling between forested landscapes and turbulent fluxes of energy, water, and carbon has become a national priority, as evidenced by both theUSGCRP's Water and Carbon Cycle Science Plans. Here, a conceptual model is proposed to describe turbulent transport of mass and energy between forest canopies and the atmosphere in terms of two end-member flow types: mixing layer (over dense vegetation) and rough walled boundary layer. Regions with varying degrees of sparse vegetation are represented as a superposition of the two end member regimes. The overarching goal is the development of a similarity theory for canopy sublayer (CSL) transport, where vertical transport phenomena are described by coupling high resolution surface features (that are readily observed remotely) and coarse resolution atmospheric fields (as both observed and modeled). The project is structured to test three hypotheses regarding the underpinnings of the conceptual model. The focus is on the interplay between canopy morphology and organized turbulent transport. Analysis of Field data is combined with Large, Eddy Simulation (LES) - with the data providing observations of field conditions and the LES providing a full view of the evolving structure of turbulence under controlled boundary conditions. The LES results will be used to identify the essential dynamics and to formulate signatures of the coherent structures that will be used to guide subsequent analysis of the field data sets. Multi-scale decompositions of the turbulence fields are to be used in concert with nonlinear time series analysis tools to begin the development of the low-dimensional model. This approach will provide a unique training experience for a graduate student and post-doc. The PI's will continue recruiting/training under-represented candidates.