Abstract. Cold extremes have large impacts on human society. Understanding the physical processes dominating the changes in cold extremes is crucial for a reliable projection of future climate change. The observed cold extremes have decreased during the last several decades, and this trend will continue under future global warming. Here, we quantitatively identify the contributions of dynamic (changes in large-scale atmospheric circulation) and thermodynamic (rising temperatures resulting from global warming) effects to East Asian cold extremes in the past several decades and in a future warm climate by using two sets of large-ensemble simulations of climate models. We show that the dynamic component accounts for over 80 % of the cold-month (coldest 5 % boreal winter months) surface air temperature (SAT) anomaly over the past 5 decades. However, in a future warm climate, the thermodynamic change is the main contributor to the decreases in the intensity and occurrence probability of East Asian cold extremes, while the dynamic change is also contributive. The intensity of East Asian cold extremes will decrease by around 5 °C at the end of the 21st century, in which the thermodynamic (dynamic) change contributes approximately 75 % (25 %). The present-day (1986–2005) East Asian cold extremes will almost never occur after around 2035, and this will happen 10 years later due solely to thermodynamic change. The upward trend of a positive Arctic Oscillation-like sea level pressure pattern dominates the changes in the dynamic component. The finding provides a useful reference for policymakers in climate change adaptation activities.

中文翻译：

---

由于热力学和动态变暖，未来东亚极端寒冷天气将减少


摘要。极端寒冷对人类社会产生巨大影响。了解主导极端寒冷变化的物理过程对于可靠预测未来气候变化至关重要。过去几十年来，观测到的极端寒冷事件有所减少，并且在未来全球变暖的情况下，这一趋势将持续下去。在这里，我们通过使用两组模型，定量确定了动态（大规模大气环流的变化）和热力学（全球变暖导致的气温上升）效应对东亚过去几十年极端寒冷和未来温暖气候的贡献。气候模型的大型集合模拟。我们表明，过去 5 年来，动态成分占寒冷月份（最冷 5% 的北方冬季月份）地表气温 (SAT) 异常的 80% 以上。然而，在未来气候变暖的情况下，热力变化是东亚极寒事件强度和发生概率降低的主要贡献者，动力变化也有贡献。到21世纪末，东亚极寒天气的强度将下降5℃左右，其中热力学（动力）变化的贡献约为75％（25％）。目前（1986-2005）东亚的极端寒冷事件在2035年左右之后几乎不会发生，而这将在10年后发生，这仅仅是由于热力学的变化。类似于北极涛动的正海平面压力模式的上升趋势主导了动态分量的变化。这一发现为政策制定者开展气候变化适应活动提供了有益的参考。