Surface sensitive studies on the heterogeneous photochemistry of multicomponent aerosols relevant to atmospheric environments

与大气环境相关的多组分气溶胶异质光化学的表面敏感研究

• 批准号: 327088-2011
• 负责人: AlAbadleh, HindA
• 金额: $ 2.55万
• 依托单位: Wilfrid Laurier University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=571920
• 关键词: Surface; sensitive; studies; heterogeneous; photochemistry

The lower atmosphere, or troposphere, comprises a large concentration of minute airborne particles known as aerosols. Atmospheric aerosols are emitted from natural sources (e.g. dust, sea salt), and from human activities (e.g. soot). They have complex chemical composition and they impact the global climate by influencing the amount of sunlight reaching the Earth's surface. Computer simulations of the climate give us the capability of quantifying the magnitude of aerosols' contribution to climate change. Yet aerosols' representation in these simulations is still inadequate, mainly because aerosols are complicated in nature and their reactivity and properties change with time. Thus, it is imperative to address scientific questions related to the chemistry of aerosols through experimental studies. The funding requested in this proposal will be used to tackle an important scientific problem, which is the role of solar radiation and metals in transforming organic matter in aerosols. The organic content of aerosols originates from pollution stemming from human activity, natural sources (emissions from trees and animals), and biomass burning. We will work with mimics of multicomponent aerosols composed of photoreactive chemicals and metals, and ubiquitous humic-like substances and amino acids. We will use experimental techniques that allow monitoring reactions on the surfaces of these materials under controlled environments, mimicking atmospheric conditions, so that results may be extrapolated to the "real world" system. Results obtained from these studies will increase our understanding of the role of photochemistry in modifying the chemical and physical properties of atmospheric particulate matter and its impact on gas phase species.

较低的大气层或对流层由大量被称为气溶胶的微小空气悬浮粒子组成。大气气溶胶来自自然来源(如粉尘、海盐)和人类活动(如烟尘)。它们具有复杂的化学成分，它们通过影响到达地球表面的太阳光的量来影响全球气候。对气候的计算机模拟使我们能够量化气溶胶对气候变化的贡献程度。然而，气溶胶在这些模拟中的表现仍然不够充分，主要是因为气溶胶的性质复杂，其反应性和性质随着时间的推移而变化。因此，必须通过实验研究来解决与气溶胶化学有关的科学问题。 这项提案中要求的资金将用于解决一个重要的科学问题，即太阳辐射和金属在气溶胶中转化有机物质中的作用。气溶胶的有机含量来自人类活动、自然来源(树木和动物排放)和生物质燃烧产生的污染。我们将使用由光反应化学品和金属组成的多组分气溶胶的模拟物，以及普遍存在的类似腐殖质的物质和氨基酸。我们将使用实验技术，允许在受控环境下监测这些材料表面的反应，模拟大气条件，以便结果可以外推到“真实世界”系统。这些研究的结果将加深我们对光化学在改变大气颗粒物的化学和物理性质及其对气相物种的影响方面的作用的理解。