Collaborative Research: Dispersion of Particles Within and Above Plant Canopies

支持的研究将确定近地面气流与植物冠层相互作用所特有的大气湍流特征，并进而确定控制小颗粒释放和运输的机制（例如，花粉粒、孢子、种子等）在这样的树冠中。 动态相互作用将通过现场观测、实验室水槽实验和高分辨率数值模拟相结合来表示，从而推动对边界层中颗粒输送的预测，使其超越目前的模型，这些模型通过稳定、均匀的扩散系数来表示湍流输送。 通过这种方式，将定量地确定单个相干流结构在释放、捕获和输送颗粒中的作用。 本研究将联合收割机水槽试验与人工冠层控制实验室条件下，在实际作物的背景下进行田间试验相结合（由宾夕法尼亚州立大学的罗克斯普林斯农场研究设施提供便利），和大涡模拟（LES）模式的数值试验。这项工作的智力价值来自于对植被的更好理解-大气相互作用涉及美国中西部典型的农作物产生的湍流过程，其与大气行为和植物冠层内的生物过程都相关。 这项研究的更广泛的影响将集中在改进的表示和预测模式的大气湍流内和上方的植物冠层，并将涉及强烈的跨学科工作在大气和生物科学的接口。 各种各样的研究生和本科生教育机会将在不同的现场实验，实验室和数值分析设置提供，并将包括学生参与将在PSU现场研究设施进行的航空生物学现场课程。

The supported research will determine characteristics of atmospheric turbulence unique to near-surface airflow interaction with plant canopies, and in-turn identify mechanisms controlling the release and transport of small particles (e.g., pollen grains, spores, seeds, etc.) within such canopies. Dynamic interactions will be represented by a combination of field-observations, laboratory water-channel experiments and high-resolution numerical simulations advance the prediction of particle transport in boundary layers beyond current models, which represent turbulent transport via steady, homogenous diffusion coefficients. In this way, the role of individual coherent flow structures in releasing, capturing and transporting particles will be quantitatively determined. This research will combine flume experiments with artificial canopies under controlled laboratory conditions, field experiments in the context of actual crops (as facilitated by Pennsylvania State University's Rock Springs Farm research facility), and numerical experiments using large-eddy simulation (LES) models.The Intellectual Merit of this effort derives from improved understanding of vegetation-atmosphere interactions involving turbulent processes generated by agricultural crops typical of those across the Midwestern U.S., which has relevance both to atmospheric behavior and biological processes within plant canopies. Broader impacts of this research will center on improved representation and prediction of modes of atmospheric turbulence generated within and above plant canopies, and will involve strongly interdisciplinary work at the interface of the atmospheric and biological sciences. A variety of graduate and undergraduate educational opportunities will be provided within diverse field-experiment, laboratory and numerical analysis settings, and will include student participation in an Aerobiology Field Course to be conducted at the PSU field research facility.