沙尘和人为污染混合型气溶胶的理化特性和辐射效应

Dust and anthropogenic pollution aerosols mix frequently in East Asia and the aerosol mixtures of dust and anthropogenic particulates have further increased in Northwest China in recent years. However, the understanding of physico-chemical properties and radiative effects of dust and anthropogenic aerosol mixtures is poor so far due to a lack of systematic study, which severely limits the assessment of aerosol climate and environment effects. Systematic study of dust and anthropogenic aerosol mixtures will be carried out based on intensive observations at the Semi-Arid Climate and Environment Observatory of Lanzhou University and data sets of aerosols and meteorological fields in East Asia: Physico-chemical property data set for dust and anthropogenic aerosol mixtures will be established; Possible ways for the mixing of dust and anthropogenic aerosols will be explored; Quantitative relationship will be built between aerosol mixing state and optical parameters; The influence of dust and anthropogenic aerosol mixtures on temperature stratification and atmospheric stability will be investigated finally. The program is designed to reveal the mechanism of how aerosol mixing state affects optical properties and to explore physical mechanism of the influence of dust and anthropogenic aerosol mixtures on temperature stratification and atmospheric stability by aerosol-radiation interactions. Our study results will provide scientific evidence to better understand the evolution mechanism of heavy pollution and improve numerical forecasting of the air pollution in dust transport regions of East Asia.

沙尘和人为污染气溶胶的混合在东亚区域频发，而近年来我国西北地区沙尘和人为污染混合型气溶胶进一步增多。但由于缺乏系统研究，目前对沙尘和人为污染混合型气溶胶理化特性和辐射效应的认识还比较薄弱，严重制约了气溶胶气候和环境效应的评估。本项目拟在兰州大学半干旱气候与环境观测站开展气溶胶加强观测，结合区域上的气溶胶和气象场资料，系统研究沙尘和人为污染混合型气溶胶的理化特性和辐射效应：建立沙尘和人为污染混合型气溶胶理化特性数据集；分析沙尘和人为污染气溶胶可能的混合方式；构建气溶胶混合状态与光学参数之间的定量关系；诊断沙尘和人为污染混合型气溶胶对温度层结和大气稳定度的影响。项目将揭示沙尘和人为污染气溶胶混合状态对光学特性的影响机理，探讨沙尘和人为污染混合型气溶胶通过辐射作用影响温度层结和大气稳定度的物理机制，为更好地理解东亚沙尘传输区域重污染过程的发生发展机理和改进空气污染数值预报提供理论依据。

沙尘和人为污染气溶胶的混合在东亚区域频发，而近年来我国西北地区沙尘和人为污染混合型气溶胶进一步增多。但由于缺乏系统研究，目前对沙尘和人为污染混合型气溶胶理化特性和辐射效应的认识还比较薄弱，严重制约了气溶胶气候和环境效应的评估。因此，本项目系统研究了沙尘和人为污染混合型气溶胶的理化特性和辐射效应。.按计划开展了气溶胶加强观测实验，建立了沙尘和人为污染混合型气溶胶理化特性数据集，研究了沙尘和人为污染气溶胶混合状态对光学特性的影响，分析了混合型气溶胶对温度层结的影响，揭示了混合型气溶胶对区域大气稳定度和空气污染程度的影响。在以下两个方面取得重要进展：（1）厘清了沙尘和人为污染气溶胶的混合对气溶胶光学特性的影响机理；（2）揭示了沙尘和人为污染混合型气溶胶的辐射效应。此外，研究指出半干旱区兰州冬季适合开展沙尘和人为污染气溶胶混合的研究，揭示了冬季边界层结构和温度层结的日变化，并量化了元素碳、细沙尘和有机碳对气溶胶吸收性的贡献。.完成了项目的研究目标，相关研究成果发表本项目标注的SCI论文10篇。其中SCI一区和二区论文9篇，Nature Index期刊论文2篇，项目负责人作为第一作者或唯一通讯作者的论文8篇。培养了4名博士研究生和3名硕士研究生，这些研究生均发表了本项目标注的第1作者或第2作者（导师第一作者）SCI论文，取得了良好的培养效果。基于本项目对观测手段和分析方法的改进，申请实用新型专利4项，其中3项已经获批。.本项目获得的沙尘和人为污染气溶胶混合影响气溶胶光学特性和辐射效应的相关成果，能够改进气象和气候模式中气溶胶的参数化，为更好地理解东亚沙尘传输区域重污染过程的发生发展机理和改进空气污染数值预报提供理论依据。