关中地区棕碳气溶胶的地球化学特征及环境效应

棕碳（BrC）作为气溶胶中有机碳的重要组成，由于其吸光效应明显，其分布、来源和环境气候效应是当前国际气溶胶领域研究的前沿和热点问题。关中地区是我国空气污染较为严重的地区之一，碳气溶胶浓度较高。本项目通过对关中地区气溶胶进行为期2年的观测研究，采用先进的7波段DRI 2015碳分析仪结合水溶性有机碳吸光性实验测定环境空气中BrC的浓度分布和光学特征。开展取暖燃烧源（秸秆和煤）棕碳排放谱研究，获得不同排放源BrC的粒径分布和光学特征，定量评估不同排放源BrC的排放量。结合环境和源排放样品化学组成数据，准确评估关中地区BrC的分布和来源，探讨正常天气和重霾天气BrC的形成和对能见度的影响。

Brown Carbon (BrC) is regarded as an important light-absorbing organic matter and has been drawing much scientific attention recently due to its role in driving global warming. The distribution, origin and optical properties of BrC aerosol will be investigated at Guanzhong Plain in Shaanxi province under this project. A state of the art 7 waves DRI 2015 carbon analyzer will be applied to measure ambient BrC levels along with light absorption of water-soluble organic carbon to obtain the optical properties of BrC (e.g. mass absorption coefficient and Ångström). Further properties such as size distribution and optical properties of BrC in biomass and coal burning emissions will also be determined in order to identify BrC source profile during heating season. The origin of BrC in Guanzhong Plain will ultimately be resolved by combining the chemical composition between ambient and sources samples together with the formation of BrC and corresponding visibility effect in haze/normal days.