Anthropogenic Influence on Oxidative Capacity and BVOC Oxidation During GoAmazon 2014

GoAmazon 2014 期间人为对氧化能力和 BVOC 氧化的影响

• 批准号: 1628491
• 负责人: Frank Keutsch
• 金额: $ 20.51万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2017-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1628491&HistoricalAwards=false
• 关键词: Anthropogenic; Influence; Oxidative; Capacity; BVOC

This project is focused on improving the mechanistic understanding of processes controlling the oxidative capacity of the atmosphere in the Amazon, a region with high concentrations of biogenic volatile organic compounds (BVOC), and investigating the anthropogenic influences on these processes. These objectives will be pursued through a field study in the central Amazon downwind of the industrial city of Manaus (population 2 million), Brazil, during two intensive operating periods (IOPs) (Feb/Mar and Aug/Oct 2014). The Amazon is a good location for this work since the intense sunlight, high BVOC emissions dominated by isoprene, and sustained high OH concentrations result in rapid photochemical processing and formation of secondary organic aerosol (SOA).In-situ measurements of BVOC oxidation products, such as glyoxal, methylgloxal, and formaldehyde, that have different OH-dependent formation or loss pathways, will be used along oxidation product ratios and modeling efforts to determine the key chemical mechanisms of BVOC oxidation during both the wet and dry seasons. During the wet season, measurements at the site are expected to provide data related to "clean" conditions, while during the dry season the polluted plume from Manaus is expected to impact the site, providing information about the anthropogenic influence (especially that of NOx) on BVOC oxidation. A better understanding of these mechanisms will clarify the extent to which hydroxyl radicals are recycled following reactions with BVOC in tropical forests. This research will to contribute to improved global/regional prediction of greenhouse-gas lifetimes and aerosol effects from precursor emissions on climate, air quality, public health, and the environment. It is an important contribution to the larger GoAmazon-2014 campaign supported by the U.S. Department of Energy and the government of Brazil to look at the coupled atmosphere-cloud-terrestrial tropical systems.

该项目的重点是改善对控制亚马逊大气氧化能力的过程的机械理解，亚马逊是一个具有高浓度的生物挥发性有机化合物（BVOC）的区域，并研究了对这些过程的人为影响。这些目标将通过在两个密集的营业时间（IOPS）（2014年2月和2014年8月/10月）的工业城市Manaus（200万人口）的亚马逊中部的野外研究来实现。亚马逊是这项工作的好地方，因为强烈的阳光，高的BVOC排放量由异戊二烯支配，并且持续的高OH浓度会导致快速的光化学处理和次级有机气溶胶（SOA）的形成。诸如具有不同OH依赖性的形成或损耗途径的乙二醛，甲基氧和甲醛将沿氧化产物比和建模努力来确定湿季期间BVOC氧化的关键化学机制。在潮湿季节，预计该地点的测量值将提供与“干净”条件有关的数据，而在干旱季节，Manaus污染的羽流有望影响该地点，从而提供有关人为影响的信息（尤其是NOX的影响）在BVOC氧化上。更好地理解这些机制将阐明在热带森林中与BVOC反应后，羟基自由基在多大程度上被回收。这项研究将有助于改善对气候，空气质量，公共卫生和环境的前体排放对温室气体寿命和气溶胶影响的全球/区域预测。这是对美国能源部和巴西政府支持的大型果阿森-2014竞选活动的重要贡献，以研究耦合的气氛 - 云云 - 透露的热带系统。