Spectral Analysis of Brown Carbon Secondary Organic Aerosol from the IR to the UV

棕碳二次有机气溶胶从红外到紫外的光谱分析

• 批准号: 1439045
• 负责人: Paul Kleiber
• 金额: $ 41.1万
• 依托单位: University of Iowa
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1439045&HistoricalAwards=false
• 关键词: Spectral; Analysis; Brown; Carbon; Secondary

Carbonaceous atmospheric aerosols, including black and brown carbon, impact climate through altering the optical properties of the atmosphere, and also by themselves undergoing further photochemical oxidation, in a poorly understood manner. This in turn may alter their own optical properties. The overall goal of this work is to improve the scientific basis for quantitatively modeling organic aerosol radiative effects. The results have application in remote sensing data retrieval algorithms, improving the reliability of radiative transfer models for aerosol and climate forcing calculations, and better understanding the impact of brown carbon (BrC) aerosol may have on atmospheric chemistry and climate. In previous work, University of Iowa researchers developed specialized laboratory optical capabilities to measure dust aerosol optical properties over the UV-Vis-IR spectrum, and have explored how physicochemical processing of aerosols alters those properties. Here they will further extend their experimental capabilities with a highly sensitive technique, cavity ring down laser spectroscopy (CRDS). This will be used to precisely measure the optical properties of the brown carbon (BrC) fraction of ambient and laboratory mimics of organic aerosols, across the visible and the mid-IR spectral range. How those properties may change as a result of UV photochemical processing will be further studied.

碳质大气气溶胶，包括黑色和棕色碳，通过改变大气的光学性质影响气候，本身也以一种鲜为人知的方式进行进一步的光化学氧化。这反过来可能会改变它们自己的光学性质。这项工作的总体目标是改善定量模拟有机气溶胶辐射效应的科学基础。这些结果在遥感数据反演算法中有应用，提高了用于气溶胶和气候强迫计算的辐射传输模式的可靠性，并更好地理解了棕色碳(BRC)气溶胶可能对大气化学和气候产生的影响。在之前的工作中，爱荷华大学的研究人员开发了专门的实验室光学功能，以测量UV-VIS-IR光谱上的尘埃气溶胶光学特性，并探索了气溶胶的物理化学处理如何改变这些特性。在这里，他们将进一步扩展他们的实验能力，使用一种高灵敏度的技术--腔衰荡激光光谱学(CRDS)。这将用于在可见光和中红外光谱范围内精确测量环境和实验室模拟有机气溶胶的棕色碳(BRC)部分的光学性质。这些特性将如何由于紫外光化学处理而改变将被进一步研究。