利用宇宙射线成因核素7Be对京津冀地区细粒大气气溶胶的示踪研究

本课题拟通过比较7Be在以京津冀为代表的雾霾高发地区，雾霾事件发生前后及发生时的粒度分布特征，建立7Be为大气细粒物质的示踪模型，进一步了解细粒污染物排放和大气气团静稳状态对雾霾形成的相对贡献；并利用大气气溶胶的7Be活性中值动力学直径（AMAD）估算大气气溶胶的平均停留时间，为利用7Be 作为大气污染物来源辨析以及大气环流迁移的地球化学示踪剂的可能性及局限性提供科学依据。具体目标为：1）查明大气气溶胶质量中值直径、7Be 活度中值空气动力学直径、7Be与典型污染物和微量元素粒度分布模态之间的关系及影响因素；2）估算大气气溶胶的平均停留时间；3）得出利用7Be作为大气中污染物的来源辨析及大气环流影响因素的示踪作用机理。

This study will compare the particle-size distribution of 7Be in atmospheric aerosols in different period of fog (before, after and when haze appears) and set up the atmospheric tracer model for fine grained material using 7Be. This model can learn more about the contribution of fine particle emissions and atmospheric air static stable state for the haze formation. The average residence time of atmospheric aerosols using the AMAD of 7Be in atmospheric aerosols will be estimated to explore the possibility of using 7Be as a geochemical tracer for atmospheric pollutants and providing scientific evidence. The aims of this project are (1) to identification of atmospheric aerosol mass median diameter, 7Be activity median aero-dynamic diameter (2) Estimate the average residence time of atmospheric aerosols and (3) source identifications of pollutants based on the 7Be tracer mechanism.