Investigating the light-absorbing carbonaceous aerosol lineage: The brown carbon - black carbon continuum

在过去的二十年里，人们已经确定，黑碳（BC），也被称为煤烟，是一种重要的光吸收剂，对气候变暖的影响可能仅次于二氧化碳。然而，BC的气候强迫效应具有较大的不确定性，分辨率对于限制燃烧碳的气候敏感性至关重要。造成这种不确定性的主要原因之一是对BrC的光吸收的了解有限，BrC通常与BC共发射，从而耦合了两者的影响。该项目将通过构成博士论文的主要组成部分并使本科生参与该项目来促进研究生和本科生的研究。第三，该项目将通过参与由UGA教育学院领导的研讨会来开展外展活动，旨在为双语（西班牙语）初高中学生、他们的父母和老师以及研究人员创造空间，让他们参与科学学习（STEM）活动。BrC的光吸收特性（与气候计算最相关的特性）没有得到很好的约束，报告的值变化超过两个数量级。这种变率的来源在很大程度上是未知的，这对在气候模式中表示BrC构成了重大挑战。这项工作将建立在燃烧科学领域BC形成研究的进展和PI最近的发现基础上，以了解BrC的影响。该项目的主要假设是，BrC的主要部分是由BC的有机前体组成的，并且BrC表现出连续的光吸收特性，可以与分子质量和挥发性相关。

Over the past two decades, it has been established that black carbon (BC), also known as soot, is a significant light absorber with a climate-warming effect potentially second only to carbon dioxide. However, the climate forcing effect of BC is subject to large uncertainties, and resolution is crucial for constraining the climate sensitivity of combustion carbon. One of the major contributors to this uncertainty is the limited understanding of light absorption by BrC, which is often co-emitted with BC, thus coupling the effects of the two. This project will promote graduate and undergraduate research by constituting a major component of a PhD dissertation and involving undergraduate students in the project. Third, the project will involve an outreach component through the involvement in workshops led by the UGA College of Education aiming at creating spaces where bilingual (Hispanic) middle- and high-school students, their parents and teachers, and researchers can engage in science-learning (STEM) activities. BrC light-absorption properties (the most relevant properties for climate calculations) are poorly constrained, with reported values varying over two orders of magnitude. The source of this variability is largely unknown, posing major challenges to representing BrC in climate models. This work will build on advances in BC formation research in the field of combustion science and recent findings by the PI to understand the effects of BrC. The main hypothesis of the project is that a major fraction of BrC is comprised of organic precursors of BC, and that BrC exhibits a continuum of light-absorption properties that can be correlated with molecular mass and volatility.