Collaborative Research: Dispersion of Particles Within and Above Plant Canopies

这项得到支持的研究将确定近地表气流与植物树冠相互作用所特有的大气湍流特征，进而确定控制小颗粒(例如花粉粒、孢子、种子等)释放和运输的机制。在这样的树冠下。动态相互作用将由现场观测、实验室水槽实验和高分辨率数值模拟相结合来表示，从而推动了对边界层中粒子传输的预测，而不是目前的模型，这些模型通过稳定的、均匀的扩散系数来表示湍流传输。这样，单个相干流动结构在释放、捕获和传输颗粒方面的作用将被定量地确定。这项研究将结合受控实验室条件下的人工树冠水槽实验，实际作物的田间实验(由宾夕法尼亚州立大学的岩泉农场研究设施推动)，以及使用大涡模拟(LES)模型的数值实验。这项工作的智力价值来自于更好地理解植被-大气相互作用，涉及美国中西部典型的农业作物产生的湍流过程，这与大气行为和植物冠层内的生物过程都有关联。这项研究的更广泛影响将集中在改进植物冠层内和之上产生的大气湍流模式的表示和预测，并将涉及大气和生物科学交界处的强有力的跨学科工作。将在不同的实地实验、实验室和数值分析环境中提供各种研究生和本科生教育机会，并将包括学生参加将在PSU实地研究设施进行的航空生物学实地课程。

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.