A top-down approach for apportioning black carbon aerosols to emission sources in regions with multiple competing contributors

在具有多个竞争贡献者的地区，采用自上而下的方法将黑碳气溶胶分配给排放源

• 批准号: RGPIN-2015-06784
• 负责人: Du, Ke
• 金额: $ 1.46万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=677057
• 关键词: top; down; approach; apportioning; black

Black carbon (BC), generated from incomplete combustion of carbonaceous fuels, is one of the two major airborne pollutants that drive climate change and degrade regional air quality. With a warming potential second to CO2, BC contributes the most uncertainty to climate modeling due to its short retention time in the atmosphere and poorly understood mixing, deposition, and contribution from various emission sources. BC from fossil fuel and biomass burning possesses distinct light absorbing properties and aging processes, and hence differing warming potentials. Therefore, improved source characterization is crucial for determining targets, formulating mitigation strategies, and increasing the accuracy of input anthropogenic aerosols in climate models. However, conventional bottom-up emission inventory (EI) methods have intrinsic limitations such as inaccurate emission factors, incomplete coverage of sources/sinks that cause large uncertainties.*******This research aims to develop an innovative, dual-isotope (14C-13C) based top-down approach to apportion BC to major sources as this approach eliminates the need of measuring emission factors or comprehensive surveying of sources. The near objective is to establish the method by improving the experimental procedures to minimize or quantify the level of interferences through a pilot study in Alberta where 1/3 of Canada BC is emitted from multiple competing sources. Molecular tracer studies combined with remote sensing data and air mass trajectory analysis will serve to validate the results of this method during the wildfire season. A mechanistic study is designed to investigate the removal mechanism of the two types of BC, so as to explain the discrepancy between the bottom-up and top-down approaches. The mid- and long term objectives are to apply this approach for investigating important BC emission regions in Canada to construct a multi-region database containing source-resolved BC emissions, based on which the impact of source-differentiated BC on the regional climate will be assessed.*******The outcome of this research is anticipated to bring immediate benefit to the BC community in that this method, with increased adaptivity, can possibly be adopted by other researches for sourcing BC at other important emission regions in the world. In the mid-long run, the datasets to be collected in this research will enable a better simulation of the Canadian climate system by providing more accurate source parameterization. The simulation results will in turn impact the regulatory sector by providing specific constraints for bottom-up emission inventories, which will assist policymakers to develop regionally tailored mitigation strategies for black carbon by selecting the right sector to target.***

黑碳（BC）是由碳质燃料不完全燃烧产生的，是导致气候变化和降低区域空气质量的两种主要空气污染物之一。碳化碳的升温潜力仅次于二氧化碳，由于其在大气中的保留时间较短，而且人们对碳化物的混合、沉积和各种排放源的贡献知之甚少，因此它对气候模型的不确定性最大。来自化石燃料和生物质燃烧的碳黑具有独特的光吸收特性和老化过程，因此具有不同的变暖潜力。因此，改进源特征对于确定目标、制定缓解策略和提高气候模型中人为气溶胶输入的准确性至关重要。然而，传统的自下而上的排放清单（EI）方法存在固有的局限性，例如排放因子不准确，源/汇覆盖不完整，导致很大的不确定性。 ******本研究旨在开发一种创新的、基于双同位素（14C-13C）的自上而下的方法来将BC分配给主要源，因为这种方法消除了测量排放因子或对源进行全面调查的需要。近期目标是通过在阿尔伯塔省进行试点研究，通过改进实验程序来最小化或量化干扰水平，从而建立该方法，该省 1/3 的加拿大 BC 是由多个竞争源排放的。分子示踪剂研究结合遥感数据和气团轨迹分析将有助于在野火季节验证该方法的结果。机制研究旨在研究两种类型BC的去除机制，以解释自下而上和自上而下方法之间的差异。中长期目标是应用该方法调查加拿大重要的BC排放区域，构建包含源解析BC排放的多区域数据库，在此基础上评估不同来源的BC对区域气候的影响。********这项研究的成果预计将为BC社区带来直接利益，因为该方法具有增强的适应性，可能被其他研究采用 在世界其他重要排放地区采购BC。从中长期来看，本研究收集的数据集将通过提供更准确的源参数化来更好地模拟加拿大气候系统。模拟结果将通过为自下而上的排放清单提供具体约束来反过来影响监管部门，这将有助于政策制定者通过选择正确的目标部门来制定针对黑碳的区域定制缓解策略。***