Collaborative Research: Hygroscopic Properties of Aerosol Organics

合作研究：气溶胶有机物的吸湿特性

• 批准号: 0931505
• 负责人: Lynn Mazzoleni
• 金额: $ 12.54万
• 依托单位: Michigan Technological University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0931505&HistoricalAwards=false
• 关键词: Collaborative; Research; Hygroscopic; Properties; Aerosol

Aerosols contribute to the Earth's radiation balance directly by absorbing and scattering light and indirectly by nucleating cloud droplets which increase planetary albedo. Both effects depend on hygroscopic growth, but the contribution of organics to aerosol hygroscopicity is not well understood--limiting efforts to model those effects. This study will address several important questions regarding aerosol hygroscopicity through field measurements, laboratory experiments, and modeling: (1) What is the contribution of water-soluble organic carbon (WSOC) to hygroscopic growth under sub- and super-saturated conditions?; (2) What are the chemical and physical properties of WSOC?; and (3) How well can Köhler theory and thermodynamic equilibrium modeling account for observed hydroscopic growth and cloud condensation nucleus (CCN) activity of mixed inorganic and organic aerosols? To answer these questions, aerosol samples will be collected at the Desert Research Institute's high-elevation Storm Peak Laboratory (SPL) during summer. Detailed inorganic and organic composition of the samples will be measured with state-of-the-art analytical techniques to identify heretofore unspeciated high molecular weight WSOC. Water extracts of the samples and isolated WSOC will be re-aerosolized to directly measure their contribution to hygroscopic growth and CCN activity. Measured growth factors and CCN activity will be reconciled using Köhler theory and structure-based thermodynamic activity models. The results of this work will improve ability to simulate hygroscopic growth for aerosols of mixed inorganic and organic composition. The explicit treatment of high molecular weight WSOC compounds produced in this project will be incorporated into the on-line version of the E-AIM thermodynamic equilibrium model for use by researchers and students worldwide. Ultimately, the project's results will provide information that can be incorporated into large-scale climate models to better predict direct and indirect aerosol radiative effects, such as hygroscopic-growth curves for water soluble organics and parameterizations of Köhler theory for aerosols of different inorganic and organic composition. The research will be incorporated into student projects as part of the Geoscience Research at Storm Peak (GRASP) activity, which engages students from underrepresented groups. During the winter of 2010, SPL will also host atmospheric science field courses for several universities. The project will allow the students taking these courses to work together with project researchers during the field deployment. Graduate undergraduate students from the involved research groups participate in laboratory experiments, data analysis, and publication of the results.

气溶胶通过增加行星反照率的核云液滴来直接吸收和散射光，从而导致地球的辐射平衡。这两种影响都取决于吸湿性的生长，但是有机物对气溶胶吸湿性的贡献尚不清楚 - 限制了对这些效果进行建模的努力。这项研究将通过现场测量，实验室实验和建模解决有关气溶胶吸湿性的几个重要问题：（1）在亚和超饱和条件下水溶性有机碳（WSOC）对吸湿生长的贡献是什么？ （2）WSOC的化学和物理特性是什么？ （3）Köhler理论和热力学平衡建模如何解释混合无机和有机气溶胶的水平生长和云冷凝核（CCN）活性？为了回答这些问题，夏季将在沙漠研究所的高海拔风暴峰实验室（SPL）中收集气溶胶样品。样品的详细无机和有机成分将通过最先进的分析技术测量，以鉴定迄今未指定的高分子量WSOC。样品和分离的WSOC的水提取物将被重新溶解，以直接衡量其对湿润生长和CCN活性的贡献。测量的生长因子和CCN活性将使用Köhler理论和基于结构的热力学活性模型进行核对。这项工作的结果将提高模拟混合无机和有机成分气溶胶的吸湿生长的能力。该项目中生产的高分子重量WSOC化合物的明确处理将纳入E-AIM热力学平衡模型的在线版本中，以供全球研究人员和学生使用。最终，该项目的结果将提供可以纳入大规模攀岩模型的信息，以更好地预测水固体组织的直接和间接气溶胶辐射效应，例如用于水固体组织的吸湿性增长曲线以及Köhler理论的参数，用于不同无机和有机成分的气溶胶。这项研究将作为Storm Peak（GRASP）活动的地球科学研究的一部分纳入学生项目，该研究吸引了代表性不足的群体的学生。在2010年冬季，SPL还将为几所大学举办大气科学课程。该项目将允许学生在现场部署期间与项目研究人员一起工作。参与实验室实验，数据分析和结果发布的研究小组的研究生本科生。