大气氧化状态的演化历史对于研究气候变化过程中大气化学对全球气候的影响和反馈具有重要价值。然而长期以来由于缺乏合适的反应古代大气氧化水平的气候代用指标，使之人们对于过去大气氧化能力的演化一直缺乏直接的证据。冰芯中硫酸盐（SO42-）的过量氧-17的测定展示了其作为解析过去大气氧化状态的有力工具。本项目我们拟通过中山-昆仑站表层雪、雪坑、冰芯以及气溶胶样品的过量氧-17分析，结合极区大气氧化条件的特异性，研究东南极地区SO42-的生成机制及其时空变化特征，初步明确东南极冰盖不同区域雪冰中SO42-的生成机制及其同位素构成的大气氧化信息指示意义，在此基础上进一步探讨海洋生物硫（冰芯硫酸盐的主要来源）排放对于大气硫酸气溶胶的影响，初步识别平流层气溶胶沉降对东南极高原区域降雪中SO42-的贡献，为精确解读雪冰SO42-记录及重建过去大气氧化状态提供依据。

The ancient atmospheric oxidation evolution is most valuable to study the impact and response of atmospheric chemistry on global climate during climate change. However, because of the lack of appropriate index to reflect ancient oxygen level, there has been no direct proof to understand evolution history of ancient atmospheric oxidation capacity. Measurements of Δ17O-SO42- may provide insight into the atmosphere oxidation capacity in the past. In this project, by means of analysis of excess 17O in the surface snow, snow pit, shallow ice core and aerosol collected along the traverse route from Zhongshan Station to Kunlun Station, combine with specificity of atmospheric oxidant level in polar region, we plan to investigate sulfate formation mechanism and its spatio-temporal change characteristic, and make preliminary understanding of sulfate formation mechanism and its isotope composition in different region of East Antarctica. Based on these deduction, we make further discuss of the impact of marine biogenic sulfur release on sulfate aerosol, and preliminarily recognize the contribution of stratospheric aerosol deposition to surface snow SO42- in inland plateau region of east Antarctica. These results will provide basis to interpretate ice core SO42- record and reconstruct past atmospheric oxidation history.