Sea ice cools Earth by reducing its absorbed solar energy. We combine radiative transfer modeling with satellite-derived surface albedo, sea ice, and cloud distributions to quantify the top-of-atmosphere sea ice radiative effect (SIRE). Averaged over 1980–2023, Arctic and Antarctic SIREs range from −0.64 to −0.86 W m⁻² and −0.85 to −0.98 W m⁻², respectively, with different cloud data sets and assumptions of climatological versus annually-varying clouds. SIRE trends, however, are relatively insensitive to these assumptions. Arctic SIRE has weakened quasi-linearly at a rate of 0.04–0.05 W m⁻² decade⁻¹, implying a 21%–27% reduction in the reflective power of Arctic sea ice since 1980. Antarctic sea ice exhibited a regime change in 2016, resulting in 2016–2023 Antarctic and global SIRE being 0.08–0.12 and 0.22–0.27 W m⁻² weaker, respectively, relative to 1980–1988. Global sea ice has therefore lost 13%–15% of its planetary cooling effect since the early/mid 1980s, and the implied global sea ice albedo feedback is 0.24–0.38 W m⁻² K⁻¹.

中文翻译：

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1980年至2023年地球海冰辐射效应


海冰通过减少地球吸收的太阳能来冷却地球。我们将辐射传输模型与卫星获取的表面反照率、海冰和云分布相结合，以量化大气层顶部海冰辐射效应（SIRE）。 1980年至2023年期间，北极和南极SIRE的平均范围分别为-0.64至-0.86 W m ⁻² 和-0.85至-0.98 W m ⁻² ，具有不同的云数据集和气候与每年变化的云的假设。然而，SIRE 趋势对这些假设相对不敏感。北极SIRE以0.04–0.05 W m ⁻² 十年 ⁻¹ 的速率准线性减弱，这意味着自1980年以来北极海冰的反射能力减少了21%–27%南极海冰在 2016 年表现出状态变化，导致 2016-2023 年南极和全球 SIRE 分别比 1980-1988 年弱 0.08-0.12 和 0.22-0.27 W m ⁻² 。因此，自 20 世纪 80 年代初/中期以来，全球海冰已经失去了 13%–15% 的行星冷却效应，隐含的全球海冰反照率反馈为 0.24–0.38 W m ⁻² K ⁻¹