Hydrogen Peroxide Fluxes to Forest Canopies: Field & Laboratory Experiments

9508417克莱伯恩大气过氧化氢在对流层光化学和云水中二氧化硫转化为硫酸的过程中发挥重要作用，对植被也可能是有毒的。植物与大气过氧化氢之间的相互作用是大气科学界和植物科学界都感兴趣的问题。虽然量化过氧化氢对植被的干沉积速率对于光化学模型是必要的，但试图测量过氧化氢对植物的沉积的研究很少。在以前的工作中已经证明，在现场和实验室实验中，以足够的精度测量过氧化氢是可能的，以便能够计算通量。在这项工作中，建议采用一种更直接的通量测量方法，即松弛涡旋累积(REA)方法，来测量森林树冠上的过氧化氢通量。然后，在三年的时间里，首席调查员将进行两种类型的实验：1)实地测量过氧化氢对森林树冠的沉积速率，2)对代表森林研究中发现的一些相同物种的单个树苗进行对照室内实验。通过进行这两个实验，既可以量化实验环境条件下对树冠的沉积速率，又可以预测沉积速率如何随着环境条件的变化而变化。该教育计划以三个主要目标为基础。与拟议的研究计划一样，教育计划强调环境研究的跨学科性质。计划开发本科和研究生课程，强调污染物的跨介质行为，并利用包括化学、生物学、大气科学和工程学在内的几门科学。第二个目标是提高工科学生的沟通能力，包括研究生和本科生。第三个目标是改善留住学生，特别是来自代表人数不足的群体的学生。

9508417 Claiborn Atmospheric hydrogen peroxide plays important roles in tropospheric photochemistry and in converting sulfur dioxide to sulfuric acid in cloudwater, and may also be toxic to vegetation. The interactions between plants and atmospheric hydrogen peroxide are of interest to both the atmospheric and plant sciences communities. While quantification of its dry deposition rates to vegetation is necessary for photochemical models, there have been very few studies that have attempted to measure deposition of hydrogen peroxide to plants. In previous work it was demonstrated that it is possible, in both field and laboratory experiments, to measure hydrogen peroxide with adequate precision to enable calculation of fluxes. In this work, it is proposed to adapt a more direct measure of the flux, the relaxed eddy accumulation (REA) method, to measure hydrogen peroxide fluxes over a forest canopy. Then, over a three-year period, the principal investigator will conduct two types of experiments: 1) field measurements of deposition rates of hydrogen peroxide to forest canopies, and 2) controlled chamber experiments on individual saplings representing some of the same species found in the forest studies. By conducting both experiments, it will be possible to both quantify the deposition rate to the canopy under the environmental conditions of the experiment, and to predict how the deposition rate changes with changing environmental conditions. The education plan is based upon three main objectives. Like the proposed research plan, the education plan emphasizes the cross-disciplinary nature of environmental studies. Development of both undergraduate and graduate courses that emphasize the cross-media behavior of pollutants and that draw upon several sciences including chemistry, biology, atmospheric sciences, and engineering, is planned. The second objective is to improve communication skills of engineering students, both at the graduate and undergraduate levels. The third objective is to improve retention of students, particularly from underrepresented groups.