伊吾泥炭中人工放射性钚同位素时间序列数据集（过去100 a）

利用过去百年间伊吾泥炭中239，240Pu的水平及其变化，探索区域239，240Pu的来源、保存和再分配过程。数据结果显示239，240Pu的浓度变化与典型大气沉降物相似，呈特征的双峰分布形式，峰值与全球大气核武器试验两个峰值时期吻合时240Pu/239Pu比值与全球沉降无异，表明区域239，240Pu主要来源于全球大气核武器试验降尘。泥炭中239，240Pu显示良好的保存特性，并未显著向深层迁移，主要受控于伊吾泥炭接近中性的水体环境。但是239，240Pu通量（128±7 Bq/m2）却明显高于同纬度带、近岸、低沙尘通量区域的值，以及在1980年大气核武器试验全面停止后，239，240Pu的浓度与泥炭有机质含量呈非典型的负相关（r=-0.79， P<0.01）。通过与区域年均温、冰川积累量、冰川中陆源碎屑含量等综合对比分析可知，239，240Pu浓度高值均发生在冷干、沙尘频发的年份，说明大气核武器试验停止后，从周围戈壁荒漠、沙漠等沙尘源区悬浮起来的沙尘，可以携带239，240Pu传输并再次沉降保存在伊吾泥炭中。经计算该部分239，240Pu的沉降通量约为77 Bq/m2，甚至超过大气核武器试验直接沉降量（51 Bq/m2）。本研究创新性地针对干旱区大气核武器试验来源239，240Pu的环境行为展开讨论，并首次定量化计算核武器试验停止后再迁移的贡献量，为多类环境科学研究提供了重要的标尺，以拓展239，240Pu的示踪应用范围和潜力。

Using the activity concentrations and temporal variations of 239,240Pu in Yiwu peat over the past century, this study investigates the sources, preservation, and redistribution processes of regional 239,240Pu. The results show that the concentration trends of 239,240Pu are consistent with those of typical atmospheric fallout, displaying a characteristic bimodal distribution. The peak timings align with the two major global atmospheric nuclear weapons test periods, and the 240Pu/239Pu ratio matches that of global fallout, demonstrating that regional 239,240Pu primarily originates from global atmospheric nuclear weapons test fallout. The 239,240Pu in the Yiwu peat exhibits excellent preservation properties, with no significant migration to deeper layers, which is mainly constrained by the near-neutral aqueous environment of the peat. However, the 239,240Pu flux (128±7 Bq/m2) is significantly higher than values reported for regions at the same latitude, nearshore areas with low dust flux. Additionally, after the comprehensive ban on atmospheric nuclear weapons tests in 1980, the concentration of 239,240Pu shows an atypical negative correlation with the peat organic matter content (r=-0.79, P<0.01). Through comprehensive comparative analysis with regional mean annual temperature, glacier accumulation, and terrigenous clastic content in glaciers, it is found that high 239,240Pu concentrations occur exclusively in cold, dry years with frequent dust storms. This indicates that following the cessation of atmospheric nuclear weapons tests, dust suspended from surrounding Gobi deserts and other desert dust source areas can transport and redeposit 239,240Pu, which is then preserved in Yiwu peat. Calculations reveal that the deposition flux of this re-distributed 239,240Pu is approximately 77 Bq/m2, which even exceeds the direct fallout flux from atmospheric nuclear weapons tests (51 Bq/m2). This study innovatively investigates the environmental behavior of 239,240Pu derived from atmospheric nuclear weapons tests in arid regions, and for the first time quantitatively calculates the contribution of post-test re-migration. This work provides an important benchmark for multiple environmental science studies, expanding the tracer application scope and potential of 239,240Pu.