基于颗粒物光学检测技术的大气沙尘气溶胶形貌、混合态研究进展

Research progress on atmospheric aerosol morphology and mixing state properties based on particle optical detection technology

大气中的沙尘气溶胶颗粒物会通过与太阳辐射相互作用、参与云的形成过程等,对气候系统产生强烈影响。对流层中的沙尘气溶胶通常是含有各种粒子成分的不均匀混合物,只有通过详细了解单个沙尘粒子的理化特性才能充分认识其对气候的影响效应。基于此,对过去20年基于光学方法对大气沙尘气溶胶观测分析的研究进行了全面的综述。回顾了利用电子显微镜、激光雷达以及单颗粒质谱等光学技术的研究成果,简要介绍了基于扫描电镜和能谱、偏光特性、非对称因子等的观测分析技术,并讨论其优缺点;总结了沙尘气溶胶形貌、混合态特征研究,讨论其参与大气物理化学过程的主要方式;讨论了污染沙尘的光学性质、吸湿特性及成核能力,这些特性都对气候变化和预测有重要影响。大气中的沙尘气溶胶是复杂多样的,如何将精确的单粒子分析技术和快速响应的在线检测技术结合将是未来大气探测的研究重点,这些研究成果也将进一步扩展到气溶胶的环境和气候影响研究,以及人类健康风险评估中。

Dust aerosols in the atmosphere have a strong impact on the climate system by interacting with solar radiation and participating in cloud formation.In the troposphere,dust aerosols are usually heterogeneous mixtures of various components,and their impact on climate can be fully understood only based on a detailed understanding of the physical and chemical properties of individual dust particles.The current understanding of atmospheric dust aerosols based on optical methods in the past 20 years is reviewed.The research achievements of optical techniques such as electron microscope,lidar,and single-particle mass spectrometry are summarized,the observation and analysis techniques based on scanning electron microscope and energy spectrum,polarization characteristics,and asymmetric factors are briefly introduced,and their advantages and disadvantages are discussed.The morphology and mixing state of dust aerosol are summarized,and the main ways of their participation in atmospheric physical and chemical processes are presented as well.The optical properties,hygroscopic behavior,and nucleation ability of polluted dust,all of which have important implications for climate change and prediction,are also discussed.It is well known that various aerosol particles from different sources lead to complex mixtures of dust aerosols in the atmosphere,so how to combine accurate single-particle analysis with fast response online detection technology will be the focus of future atmospheric detection research.And it is believed that these findings will be further extended to the study of the environmental and climate impacts of aerosols,as well as human health risk assessment.