Heuzé Céline, Jahn Alexandra
Department of Earth Sciences, University of Gothenburg, Box 460, 405 30, Göteborg, Sweden.
Department of Atmospheric and Oceanic Sciences and Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO, USA.
Nat Commun. 2024 Dec 3;15(1):10101. doi: 10.1038/s41467-024-54508-3.
Projections of a sea ice-free Arctic have so far focused on monthly-mean ice-free conditions. We here provide the first projections of when we could see the first ice-free day in the Arctic Ocean, using daily output from multiple CMIP6 models. We find that there is a large range of the projected first ice-free day, from 3 years compared to a 2023-equivalent model state to no ice-free day before the end of the simulations in 2100, depending on the model and forcing scenario used. Using a storyline approach, we then focus on the nine simulations where the first ice-free day occurs within 3-6 years, i.e. potentially before 2030, to understand what could cause such an unlikely but high-impact transition to the first ice-free day. We find that these early ice-free days all occur during a rapid ice loss event and are associated with strong winter and spring warming.
迄今为止，北极无海冰的预测主要集中在月平均无冰条件上。在此，我们利用多个CMIP6模型的日输出数据，首次预测了北冰洋首次出现无冰日的时间。我们发现，根据所使用的模型和强迫情景，预测的首次无冰日范围很大，从与2023年等效模型状态相比的3年到2100年模拟结束前都没有无冰日。然后，我们采用情景分析方法，重点关注首次无冰日出现在3至6年内（即可能在2030年之前）的九次模拟，以了解可能导致这种不太可能但影响巨大的向首次无冰日转变的原因。我们发现，这些早期无冰日都发生在快速海冰损失事件期间，并且与强烈的冬季和春季变暖有关。
