U.S.-Sweden Cooperative Research: Pollutant Dry Deposition to Snow and Vegetation

9300627 Davidson这个为期三年的奖项支持卡内基-梅隆大学的克里夫·I·戴维森和查尔默斯理工大学的Mats Oblad之间的美国-瑞典合作研究。这项研究的目的是：(1)作为一项大型国际分水岭研究的一部分，对瑞典中部加德斯琼湖森林冠层中大气酸和微量元素的干沉积进行测量和模拟；(2)建立关于北极地区干沉积的模型和解释数据。研究人员将研究已知会破坏生态系统的硫酸盐和硝酸盐酸性化合物，以及已知可中和酸的某些微量元素。拟议的工作将侧重于干法沉积过程的现场测量和计算机模拟。大气中的酸通过湿沉积和干沉积输送到表面。干沉降是从大气中去除酸性化合物的一个重要机制；然而，它的过程还不是很清楚。森林沉积工作和北极地区的工作将更好地估计和了解大气颗粒与植被和雪面相互作用的物理和化学过程。卡内基梅隆大学的研究人员已经开发出独特的、对称的翼型设备来测量干沉积。这些将被设置在加德斯琼湖的森林树冠上。北冰洋干沉积模型也是由卡内基-梅隆小组开发的，将利用查尔默斯大学提供的新数据集进行测试。拟议的合作利用了瑞典在建模方法方面的专业知识和在监测森林树冠中酸性化合物沉积方面的经验。它还可以将美国网站的结果与瑞典网站的结果进行比较。***

9300627 Davidson This three-year award supports U.S.-Sweden cooperative research between Cliff I. Davidson, of Carnegie-Mellon University and Mats Oblad of the Chalmers University of Technology. The objectives of the research are (1) to measure and model dry deposition of atmospheric acids and trace elements in the Gardsjon Lake forest canopy in central Sweden as part of a large international watershed study; and (2) to develop models and interpret data on dry deposition in the Artic region. The investigators will study sulfate and nitrate acidic compounds known to cause ecosystem damage, and certain trace elements that are known to neutralize acids. The proposed work will focus on field measurements and computer modeling of dry deposition processes. Atmospheric acids are transported to surfaces by wet and dry deposition. Dry deposition is an important mechanism of removal of acidic compounds from the atmosphere; however, its processes are not well understood. The forest deposition work and the work in the Artic will provide better estimates and understanding of the physical and chemical processes by which atmospheric particles interact with vegetated and snow surfaces. The researchers at Carnegie Mellon have developed unique, symmetric airfoil devices for measuring dry deposition. These will be set up in the forest canopy at Gardsjon Lake. The models on dry deposition in the Artic, also developed by the Carnegie-Mellon group, will be tested utilizing new datasets available at Chalmers University. The proposed collaboration takes advantage of Swedish expertise in modeling methods and experience in monitoring the deposition of acidic compounds in a forest canopy. It also allows comparision of results at American sites with those from Swedish sites. ***