Tracing the Origin and Measuring the Deposition of Aerosols Over the North Atlantic Ocean Through the Use of 210 Pb and 7Be (AEROCE)

使用 210 Pb 和 7Be 追踪源头并测量北大西洋上空气溶胶的沉积 (AEROCE)

• 批准号: 8701292
• 负责人: Karl Turekian
• 金额: $ 33.8万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-09-15 至 1991-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8701292&HistoricalAwards=false
• 关键词: Tracing; Origin; Measuring; Deposition; Aerosols

Over the past 10-15 years atmospheric chemistry has evolved from a young research discipline devoted primarily to local problems of urban pollution and air quality to a mature science concerned with the hemispheric to global scale cycling of a wide variety of chemical species. To a large extent this change has resulted from an increasing realization that human activities can cause chemical disturbances to the natural troposphere on scales far beyond local concerns. Well-known examples include changes in the regional-to-global concentrations of certain nitrogen compounds, lead and other heavy metals, artificial radionuclides, a number of synthetic organic substances, certain acid-forming species, carbon dioxide and methane. These chemical changes in the atmosphere can often extend to the earth's soils, oceans, and biota far from the original source region. They can result in alterations in the earth's climate, changes in vital nutrient cycles, and impact significantly on the public health and quality of life on earth. The Atmosphere/Ocean Chemistry Experiment (AEROCE) will be a coordinated multi-institutional atmospheric and marine chemistry research project centered in the North Atlantic region. The ultimate goal of the AEROCE project will be the development of a predictive capability for the continentally derived species observed in the marine troposphere over the North Atlantic. The selection of sites and the measurement protocol in AEROCE has been developed jointly by modelers and field experimentalists. This element of the AEROCE research project is designed to measure: (1) the concentration of 210Pb and 7Be in all aerosol samples collected as part of the standard AEROCE protocol at all sites, (2) the monthly deposition flux of 210Pb and 7Be to all sites and (3) the long term mean deposition rates of 137Cs and 210Pb to soils at a majority of the sites. These nuclides have well known sources and do not undergo chemical transformations. This research seeks to achieve 5 objectives: (1) The observed concentrations and deposition of these nuclides will be used to test and refine both event-oriented and climatological numerical models of atmospheric transport. (2) The correlations between the radionuclides and other species will be used to infer the sources of the other species and of seasonal changes in source or transport. (3) The ratio of deposition rate to surface air concentration will be used to quantify the efficiency of transfer of aerosols to the surface. (4) The 7Be/210Pb ratio will be developed as a measure of vertical mixing in the troposphere. (5) Comparison of 7Be/210Pb in air and deposition will help quantify both the absolute value and the vertical variation of these elements.

在过去的10-15年里，大气化学已经从一门主要致力于城市污染和空气质量局部问题的年轻研究学科发展成为一门关注从半球到全球范围内各种化学物种的循环的成熟科学。在很大程度上，这一变化是因为人们日益认识到，人类活动可能对自然对流层造成化学干扰，其规模远远超出了当地的关切。众所周知的例子包括某些氮化合物、铅和其他重金属、人造放射性核素、一些合成有机物质、某些产酸物种、二氧化碳和甲烷的区域对全球浓度的变化。大气中的这些化学变化通常会延伸到地球的土壤、海洋和远离原始来源地区的生物群。它们可能导致地球气候的变化，改变重要的营养循环，并对地球上的公众健康和生活质量产生重大影响。大气/海洋化学实验(AEROCE)将是一个以北大西洋区域为中心的协调的多机构大气和海洋化学研究项目。AEROCE项目的最终目标将是发展对北大西洋上空海洋对流层观察到的大陆衍生物种的预测能力。AEROCE的场地选择和测量方案是由模型师和现场实验者共同开发的。AEROCE研究项目的这一部分旨在测量：(1)作为标准AEROCE协议的一部分在所有站点收集的所有气溶胶样本中的210Pb和7Be浓度，(2)所有站点每月210Pb和7Be的沉积通量，以及(3)大部分站点土壤中137Cs和210Pb的长期平均沉积速率。这些核素具有众所周知的来源，不会发生化学转化。这项研究试图实现五个目标：(1)这些核素的观测浓度和沉积将用于检验和改进大气输送的事件导向型和气候学数值模式。(2)放射性核素与其他物种之间的相关性将被用来推断其他物种的来源以及来源或运输的季节性变化。(3)用沉降率与地面空气浓度之比来量化气溶胶向地面输送的效率。(4)7Be/210Pb值将被开发为对流层垂直混合的量度。(5)大气和沉积物中7Be/210Pb值的对比有助于量化这些元素的绝对值和垂直变化。