Dynamic changes in the cryosphere have profound implications for global warming. This study, through case studies of seasonal ice lakes and glacier-originated rivers, complemented by global data, offers novel insights into radium (Ra) isotopes' characteristic in the cryosphere. It elucidates the quantification of the “Ra quartet” as tracers in frozen hydrological processes across various timescales. (1) Theoretical case studies. Significant differences in water chemistry and Ra activities were observed, highlighting distinct Ra supply and depletion mechanisms. The improved Ra mass model was utilized to estimate the freezing duration of the lakes and the groundwater discharge beneath the ice, while also elucidating the recharge dynamics of groundwater along glacial rivers. (2) Global scale theoretical discoveries. The low 224Ra/228Ra ratio, including the case studies presented, may be a significant characteristic of the non-subterranean cryosphere. This phenomenon can be attributed to various processes, including decay, particulate scavenging, groundwater discharge, upwelling, and glacial meltwater. In contrast, the ratio observed in permafrost is more complex, potentially influenced by diverse hydrogeological conditions and intricate sampling protocols. While Ra isotopes are well-traced in the ocean cryosphere—covering groundwater discharge, water exchange, and composition-particle interactions—their application in terrestrial and atmospheric cryospheric studies remains underexplored. Our study provides novel perspectives on Ra isotopes in the cryosphere, offering crucial theoretical and practical implications for addressing ongoing climate warming.

中文翻译：

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镭指纹识别追踪气候变暖下全球冰冻圈的水文


冰冻圈的动态变化对全球变暖具有深远的影响。这项研究通过对季节性冰湖和冰川起源河流的案例研究，并辅以全球数据，为冰冻圈中镭 （Ra） 同位素的特性提供了新的见解。它阐明了“Ra 四重奏”作为不同时间尺度上冻结水文过程中示踪剂的量化。（1） 理论案例研究。观察到水化学和 Ra 活性的显着差异，突出了不同的 Ra 供应和消耗机制。改进的 Ra 质量模型用于估计湖泊的冻结持续时间和冰下的地下水排放，同时还阐明了冰川河流沿线地下水的补给动力学。（2） 全球尺度的理论发现。低 224Ra/228Ra 比率（包括所介绍的案例研究）可能是非地下冰冻圈的一个重要特征。这种现象可归因于各种过程，包括腐烂、颗粒清除、地下水排放、上升流和冰川融水。相比之下，在永久冻土中观察到的比率更为复杂，可能受到不同水文地质条件和复杂采样方案的影响。虽然 Ra 同位素在海洋冰冻圈中得到了很好的追踪——包括地下水排放、水交换和成分-粒子相互作用——但它们在陆地和大气冰冻圈研究中的应用仍未得到充分探索。我们的研究为冰冻圈中的 Ra 同位素提供了新的视角，为解决持续的气候变暖提供了重要的理论和实践意义。