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: 1321987
• 负责人: Frank Keutsch
• 金额: $ 37.49万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-12-15 至 2016-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1321987&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.

该项目的重点是提高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生物挥发性有机化合物（BVOC）的地区，并调查人类活动对这些过程的影响。这些目标将通过在两个密集运行期（2014年2月/3月和8月/10月）期间在巴西工业城市马瑙斯（人口200万）的亚马逊河中部下风处进行实地研究来实现。亚马逊是这项工作的好地点，因为强烈的阳光，异戊二烯占主导地位的高BVOC排放，以及持续的高OH浓度导致快速的光化学处理和二次有机气溶胶（SOA）的形成。BVOC氧化产物的原位测量，如乙二醛，甲基乙二醛和甲醛，具有不同的OH依赖的形成或损失途径，将被用于沿着氧化产物的比例和建模工作，以确定在潮湿和干燥的季节BVOC氧化的关键化学机制。在雨季，预计现场的测量将提供与“清洁”条件有关的数据，而在旱季，来自马瑙斯的污染羽流预计将影响现场，提供关于人为影响（特别是氮氧化物）对BVOC氧化的信息。更好地理解这些机制将澄清羟基自由基在热带森林中与BVOC反应后再循环的程度。这项研究将有助于改善全球/区域对温室气体寿命和前体排放对气候、空气质量、公共卫生和环境的气溶胶影响的预测。这是对美国能源部和巴西政府支持的更大的GoAmazon-2014运动的重要贡献，该运动旨在研究大气-云-陆地耦合热带系统。