In spite of the unabated emissions of greenhouse gases into the atmosphere, sea ice around Antarctica has increased over most of the satellite era. Such an increase is not captured by climate models, which simulate a melting over the same period. Over the last few years, moreover, the observed sea ice trends have drastically changed, and this might act to cancel the models‐observations discrepancy. Here we show that in spite of the very recent Antarctic sea ice trend changes, such discrepancy still exists. Analyzing multiple large ensembles of model simulations, we elucidate the origin of the models‐observations discrepancy. We show that internal variability cannot account for the discrepancy, which therefore is likely to stem from biases in the models' forced response to the external forcing. These biases, we show, reside in thermodynamic ocean‐atmosphere coupling, as models fail to simulate the trends in surface heat fluxes from reanalyses over the period 1979–2019.

中文翻译：

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使用多个大型集合来阐明 1979-2019 建模和观察到的南极海冰趋势之间的差异

尽管向大气排放的温室气体有增无减，但在卫星时代的大部分时间里，南极洲周围的海冰一直在增加。模拟同一时期融化的气候模型没有捕捉到这种增加。此外，在过去几年中，观测到的海冰趋势发生了巨大变化，这可能会消除模型观测的差异。在这里我们表明，尽管最近南极海冰趋势发生了变化，但这种差异仍然存在。通过分析模型模拟的多个大型集合，我们阐明了模型观察差异的起源。我们表明内部可变性无法解释差异，因此这可能源于模型对外部强迫的强制响应的偏差。这些偏见，我们表明，