Ionic impurities in superficial snow sampled in the Antarctic campaign 2019-20 along the East Antarctic International Ice Sheet Traverse (EAIIST) from Dome C to South Pole

The data set consists in the ionic composition determined by ion chromatography of the superficial snow sampled in the Antarctic Campaign 2019-20. In the framework of the "East Antarctic International Ice Sheet Traverse" (EAIIST) project, surface snow samples were collected along a traverse from Dome C (75° 06' 01'' S, 123° 20' 48'' E - East Antarctic plateau) toward the geographic South Pole during the 2019-2020 Antarctic campaign. 32 samples were collected using 50 mL tubes by personnel wearing low particulate release clothing, polyethylene gloves to minimize external contamination. The uppermost 6 cm of snow were collected by inserting the tubes into the surface snow of the sampling site upwind and at a sufficient distance from the convoy to reduce the contamination risk. The tubes were kept frozen until the analysis. The cationic (Na⁺, NH₄⁺, K⁺, Mg²⁺, Ca²⁺) and anionic (Cl⁻, NO₃⁻, SO₄²⁻) content was determined by Ion Chromatography. The reproducibility of the measurements is always better than 4% and detection limit are in the range 2-5 ug/l for anions and 0.1-0.6 ug/L for cations. Details on analytical method are reported in the paper Ventisette et al. 2023. The data set is useful to study the spatial distribution of major ions on the inner Antarctic plateau, to understand their deposition and post deposition processes in this area characterized by megadune and wind crust formation (Ventisette et al., 2023). The knowledge and quantification of these processes will allow the interpretation of the ice core stratigraphies in low snow accumulation rate.本数据集包含2019-2020年南极科考期间采集的表层雪样的离子色谱检测离子组成数据。在“东南极国际冰盖横穿计划（East Antarctic International Ice Sheet Traverse, EAIIST）”框架下，本次科考沿从 Dome C（南纬75°06′01″，东经123°20′48″，位于东南极冰盖高原）向地理南极点的横穿路线采集表层雪样。本次共采集32份雪样，采样时使用50 mL离心管，操作人员身着低颗粒物释放工作服、佩戴聚乙烯手套，以最大程度降低外部污染风险。采样时将采样管插入采样点上风处的表层积雪中，采集其最上层6 cm的雪样，且采样点与科考车队保持足够距离以进一步降低污染风险。所有采样管全程保持冷冻状态直至实验室分析。采用离子色谱法（Ion Chromatography）测定了样品中的阳离子（Na⁺、NH₄⁺、K⁺、Mg²⁺、Ca²⁺）与阴离子（Cl⁻、NO₃⁻、SO₄²⁻）含量。测量重现性均优于4%，阴离子的检出限范围为2~5 μg/L，阳离子检出限范围为0.1~0.6 μg/L。分析方法的详细信息可参见Ventisette等人2023年发表的研究论文。本数据集可用于探究东南极内陆高原主要离子的空间分布特征，解析该区域（以巨型沙丘和风成硬壳形成为典型特征）的离子沉积过程与沉积后过程（Ventisette等，2023）。对这些过程的认知与量化分析，将为低降雪累积速率区域的冰芯地层解译提供重要支撑。