Department of Earth Sciences, Uppsala University, Uppsala, 75236, Sweden.
Department of Mathematics and Statistics & Centre for the Mathematics of Planet Earth, University of Reading, Reading, RG66AX, United Kingdom.
Phys Rev Lett. 2021 Jul 30;127(5):058701. doi: 10.1103/PhysRevLett.127.058701.
Extreme events provide relevant insights into the dynamics of climate and their understanding is key for mitigating the impact of climate variability and climate change. By applying large deviation theory to a state-of-the-art Earth system model, we define the climatology of persistent heatwaves and cold spells in key target geographical regions by estimating the rate functions for the surface temperature, and we assess the impact of increasing CO_{2} concentration on such persistent anomalies. Hence, we can better quantify the increasing hazard due to heatwaves in a warmer climate. We show that two 2010 high impact events-summer Russian heatwave and winter Dzud in Mongolia-are associated with atmospheric patterns that are exceptional compared to the typical ones but typical compared to the climatology of extremes. Their dynamics is encoded in the natural variability of the climate. Finally, we propose and test an approximate formula for the return times of large and persistent temperature fluctuations from easily accessible statistical properties.
极端事件为气候动态提供了重要的见解，了解这些动态是减轻气候变率和气候变化影响的关键。通过将大偏差理论应用于最先进的地球系统模型，我们通过估计表面温度的率函数来定义关键目标地理区域中持续热浪和寒冷期的气候，并评估 CO_{2}浓度增加对这种持续异常的影响。因此，我们可以更好地量化由于气候变暖而导致的热浪风险增加。我们表明，两个 2010 年的高影响事件——俄罗斯夏季热浪和蒙古冬季 Dzud——与大气模式有关，与典型模式相比，这些模式异常，但与极端气候的气候模式相比则较为典型。它们的动态特征体现在气候的自然变异性中。最后，我们提出并测试了一种从易于获得的统计特性返回大而持续温度波动的返回时间的近似公式。
