Antarctic Ice‐Sheet Meltwater Reduces Transient Warming and Climate Sensitivity Through the Sea‐Surface Temperature Pattern Effect
Antarctic Ice‐Sheet Meltwater Reduces Transient Warming and Climate Sensitivity Through the Sea‐Surface Temperature Pattern Effect
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DOI：
10.1029/2022gl101249
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发表时间：
2022-12
影响因子：
5.2
通讯作者：
Yue Dong;Andrew G. Pauling;Shaina Sadai;K. Armour
中科院分区：
文献类型：
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作者：
Yue Dong;Andrew G. Pauling;Shaina Sadai;K. Armour
自20世纪80年代以来，耦合全球气候模式（GCM）通常无法再现观测到的海表温度（SST）趋势模式。模型-观测的差异可能部分是由于GCM中缺乏现实的南极冰盖融水输入。在这里，我们采用了两组CESM 1 ‐ CAM 5模拟，这些模拟是由1980-2013年和21世纪的异常南极融水通量造成的。两者都显示出全球变暖率降低，SST趋势模式更接近观测结果。融水推动南大洋和热带东南太平洋的表面冷却，从而增加低云覆盖，并推动辐射反馈变得更加稳定（对应于较低的有效气候敏感性）。这些反馈变化在降低全球变暖率方面的贡献与海洋吸热效率变化一样大。因此，准确预测历史和未来的变暖需要改进南极融水及其影响的代表性。
Coupled global climate models (GCMs) generally fail to reproduce the observed sea‐surface temperature (SST) trend pattern since the 1980s. The model‐observation discrepancies may arise in part from the lack of realistic Antarctic ice‐sheet meltwater input in GCMs. Here we employ two sets of CESM1‐CAM5 simulations forced by anomalous Antarctic meltwater fluxes over 1980–2013 and through the 21st century. Both show a reduced global warming rate and an SST trend pattern that better resembles observations. The meltwater drives surface cooling in the Southern Ocean and the tropical southeast Pacific, in turn increasing low‐cloud cover and driving radiative feedbacks to become more stabilizing (corresponding to a lower effective climate sensitivity). These feedback changes can contribute as substantially as ocean heat uptake efficiency changes in reducing the global warming rate. Accurately projecting historical and future warming thus requires improved representation of Antarctic meltwater and its impacts.