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

基本信息

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

项目摘要

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.

包括黑色和棕色碳在内的碳质大气气溶胶通过改变大气的光学特性，并以众所周知的方式经历了进一步的光化学氧化来影响气候。反过来，这可能会改变自己的光学特性。这项工作的总体目标是改善定量建模有机气溶胶辐射效应的科学基础。该结果在遥感数据检索算法中应用，提高了气溶胶和气候强迫计算的辐射转移模型的可靠性，并且更好地理解了棕色碳（BRC）气溶胶对大气化学和气候的影响。在以前的工作中，爱荷华大学的研究人员开发了专业的实验室光学能力，以测量UV-VIS-IR光谱上的灰尘气溶胶光学特性，并探讨了气溶胶的物理化学处理如何改变这些特性。在这里，他们将通过高度敏感的技术，腔环向下激光光谱（CRDS）进一步扩展实验能力。这将用于精确测量在可见的和中红外光谱范围内的环境和实验室模仿的棕色碳（BRC）的光学特性。将进一步研究由于紫外光化学处理而导致的这些特性如何变化。