We analyze the past 67,000 years of climate using Antarctic ice-core records to constrain the mechanisms involved in (a) the “bipolar seesaw” relationship between Greenland and Antarctic surface temperature variations, and (b) mechanisms of millennial-scale atmospheric CO₂ concentration variations. Specifically, we determine for each Greenland Stadial the rate of Antarctic temperature and atmospheric CO₂ rise. We find that Antarctic warming rates significantly decrease as the climate cools during the glacial period, whereas the rate of atmospheric CO₂ rise does not significantly change. Also, we find that the rates of Antarctic warming and atmospheric CO₂ rise are both insensitive to whether a given stadial contains a Heinrich event. These results challenge the view that a single Southern-Ocean-based mechanism dominates the observed glacial variability in Antarctic temperature and atmospheric CO₂. Instead, our results are consistent with an important contribution of low- and mid-latitude processes to millennial-scale atmospheric CO₂ changes.

中文翻译：

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末次冰期南极温度和大气 CO2 的不同趋势

我们使用南极冰芯记录分析了过去 67,000 年的气候，以约束 (a) 格陵兰和南极表面温度变化之间的“双极跷跷板”关系，以及 (b) 千年尺度大气 CO ₂浓度机制变化。具体来说，我们为每个格陵兰体育场确定南极温度和大气 CO ₂上升的速率。我们发现南极变暖率随着冰川期气候变冷而显着降低，而大气 CO ₂上升率没有显着变化。此外，我们发现南极变暖和大气 CO ₂的速率上升对给定的体育场是否包含海因里希事件都不敏感。这些结果挑战了这样一种观点，即单一的基于南大洋的机制主导了观测到的南极温度和大气 CO _{2 的}冰川变化。相反，我们的结果与低纬度和中纬度过程对千年尺度大气 CO ₂变化的重要贡献一致。