Desert aerosol aging in polluted environments and impact on its optical properties

沙漠气溶胶在污染环境中的老化及其光学特性的影响

• 批准号: 378741973
• 负责人: Professor Dr. Konrad Kandler
• 金额: --
• 依托单位: Fachgebiet Atmosphärisches Aerosol
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/378741973?language=en
• 关键词: Desert; aerosol; aging; polluted; environments

Atmospheric aerosol absorption is one of the major effects influencing the solar energy balance in terms of direct aerosol climate effect. Absorption is mainly driven by three major compounds, soot, mineral dust, and brown carbon. The relative quantities, in which these anthropogenic and natural compounds become effective, are, however, now well known. The present proposal aims therefore at a quantification of the absorbing effects of soot, organic carbon and mineral dust based on the quantification of the chemical composition and structure of many single particles by electron microscopy. As region of interest, the Eastern Mediterranean was selected because there in spring a most complex mixture of biomass burning aerosol, anthropogenic emissions, marine aerosol, and African and Asian mineral prevails. The proposed work will be performed in connection with a third-party-funded aircraft and ground-based measurement campaign, which offers the unique opportunity to obtain samples in and over the region of interest in connection with a wealth of atmospheric, aerosol and cloud measurement from third parties. Major goals of the proposed project are: A) General characterization of aerosol composition: Aerosol particle types will be identified by chemical properties and quantified. Size distributions of chemical composition will be estimated from relative chemical composition and separate size distribution measurements for sub 2.5-µm aerosol particles, as well as from a dedicated large particle collection technique directly. B) Partitioning into volatile / refractory components: Based on electron microscopy, volatile and refractory components will be identified and quantified inside single particles. Types of refractory materials will be identified. C) Assessment of dust / soot absorption partitioning based on single particles: The absorbing fraction of aged aerosol particles will be identified by their chemical and morphological properties. The volume contribution of the absorbing components will be determined by image analysis and element mapping. The according number abundance of absorbing particles will be used to determine the contribution of dust and soot. Soot particle microstructure and chemical composition will be used to determine the contribution of major soot sources. D) Exploring potential links between dust source and dust absorption: Absorption modeled through dust chemical composition will be related to dust source, based on a year-long time series of aerosol composition to allow for capturing seasonal cycles. Summarizing, the proposed project will yield new and detailed insights in absorption partitioning, potential dust contribution to radiative forcing in a polluted / mixed environment, possible connections with dust sources and soot source apportionment.

从气溶胶直接气候效应的角度来看，大气气溶胶吸收是影响太阳能平衡的主要效应之一。吸收主要由三种主要化合物驱动，烟灰，矿物粉尘和棕色碳。然而，这些人为和天然化合物的相对量现在已经众所周知。因此，本提案旨在通过电子显微镜对许多单个颗粒的化学成分和结构进行量化，从而对烟尘、有机碳和矿物粉尘的吸收效果进行量化。选择东地中海作为感兴趣的区域，是因为春季生物质燃烧气溶胶、人为排放、海洋气溶胶以及非洲和亚洲矿物的最复杂混合物占主导地位。拟议的工作将结合第三方资助的飞机和地面测量活动进行，这提供了一个独特的机会，可以在感兴趣的区域内和上空获取与第三方提供的大量大气、气溶胶和云测量有关的样本。拟议项目的主要目标是：A）气溶胶组成的一般特性：气溶胶粒子类型将通过化学特性确定并量化。化学成分的粒度分布将通过相对化学成分和亚2.5微米气溶胶颗粒的单独粒度分布测量以及直接通过专用的大颗粒收集技术来估计。B）分配成挥发性/难熔组分：基于电子显微镜，将在单个颗粒内鉴定和定量挥发性和难熔组分。将确定耐火材料的类型。C）基于单个颗粒的灰尘/烟尘吸收划分评估：老化气溶胶颗粒的吸收分数将通过其化学和形态特性来确定。吸收组分的体积贡献将通过图像分析和元素映射来确定。相应的吸收颗粒的数量丰度将用于确定灰尘和烟灰的贡献。烟尘颗粒微观结构和化学成分将用于确定主要烟尘源的贡献。D）探索粉尘源和粉尘吸收之间的潜在联系：通过粉尘化学成分模拟的吸收将与粉尘源相关，基于长达一年的气溶胶成分时间序列，以捕获季节性周期。总之，拟议的项目将产生新的和详细的见解，吸收分区，潜在的灰尘在污染/混合环境中的辐射强迫的贡献，可能的连接与灰尘源和烟尘源分配。