We present the δ¹⁸O isotope composition of 16 multi‐year ice (MYI) and eight first‐year ice (FYI) cores collected during spring from the Lincoln Sea, a region within the Last Ice Area, which is expected to retain MYI longest into the future. Isotopic signatures were used to quantify the contribution of snow to sea ice mass. These estimates yield a higher total snow contribution in MYI (10 ± 5%) than to FYI (4 ± 2%). Converted to Snow Depth Equivalent (SDE), MYI had five times larger SDE (0.79 ± 0.38 m) than FYI (0.16 ± 0.11 m). The difference is explained by the contribution of refrozen surface and under‐ice melt ponds as well as superimposed/interposed ice for MYI resulting from higher accumulation of snow over multiple, longer accumulation seasons compared to FYI. Given the impending replacement of MYI by FYI, the large difference in absolute snow contributions between MYI and FYI highlights the potential implications in terms of the redistribution of precipitation‐derived (meteoric) freshwater throughout the Arctic Ocean. Furthermore, we observed high relative snow contributions to ice mass in the surface of one‐third of older FYI cores, which we attributed to flooding and formation of snow‐ice. Our results support the premise that flooding events on FYI may be more prevalent throughout the Arctic Ocean than previously assumed.

中文翻译：

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积雪对最后一个冰区内北极第一年和多年海冰质量平衡的贡献

我们目前的δ ¹⁸ 16多年冰（MYI）和八个第一年冰（仅供参考）从林肯海，在最后一个冰河区域内的区域，预计将保持MYI最长春运期间核心收集的氧同位素组成走向未来。同位素特征被用来量化雪对海冰质量的贡献。这些估计值对MYI的总积雪贡献（10±5％）比对FYI的总积雪贡献（4±2％）高。换算为雪深当量（SDE），MYI的SDE大五倍（0.79±0.38 m）比FYI（0.16±0.11 m）大。差异的原因在于，与FYI相比，在多个较长的积聚季节中积雪的积聚，造成了冰冻表层和冰下融化池以及MYI的叠加/中间冰的贡献。鉴于国际风云国际即将替换MYI，MYI与FYI的绝对降雪量之间的巨大差异突出了整个北冰洋降水（淡水）的重新分配的潜在影响。此外，我们观察到FYI核心中三分之一的旧地表中积雪对冰块的贡献较高，这归因于洪水和积冰的形成。