Cai Fenying, Liu Caihong, Gerten Dieter, Yang Song, Zhang Tuantuan, Li Kaiwen, Kurths Jürgen
Potsdam Institute for Climate Impact Research (PIK), Member of the Leibniz Association, 14473, Potsdam, Germany.
Department of Geography, Humboldt-Universität zu Berlin, 10099, Berlin, Germany.
Nat Commun. 2024 Sep 13;15(1):8012. doi: 10.1038/s41467-024-52254-0.
Pronounced spatial disparities in heatwave trends are bound up with a diversity of atmospheric signals with complex variations, including different phases and wavenumbers. However, assessing their relationships quantitatively remains a challenging problem. Here, we use a network-searching approach to identify the strengths of heatwave-related atmospheric teleconnections (AT) with ERA5 reanalysis data. This way, we quantify the close links between heatwave intensity and AT in the Northern Hemisphere. Approximately half of the interannual variability of heatwaves is explained and nearly 80% of the zonally asymmetric trend signs are estimated correctly by the AT changes in the mid-latitudes. We also uncover that the likelihood of extremely hot summers has increased sharply by a factor of 4.5 after 2000 over areas with enhanced AT, but remained almost unchanged over the areas with attenuated AT. Furthermore, reproducing Eastern European heatwave trends among various models of the Coupled Model Intercomparison Project Phase 6 largely depends on the simulated Eurasian AT changes, highlighting the potentially significant impact of AT shifts on the simulation and projection of heatwaves.
热浪趋势中明显的空间差异与具有复杂变化的多种大气信号相关联，这些信号包括不同的位相和波数。然而，定量评估它们之间的关系仍然是一个具有挑战性的问题。在这里，我们使用网络搜索方法，利用ERA5再分析数据来识别与热浪相关的大气遥相关（AT）的强度。通过这种方式，我们量化了北半球热浪强度与AT之间的紧密联系。大约一半的热浪年际变率可以通过中纬度地区的AT变化得到解释，并且近80%的纬向不对称趋势符号能够被正确估计。我们还发现，在2000年之后，在AT增强的地区，极热夏季出现的可能性急剧增加了4.5倍，但在AT减弱的地区几乎保持不变。此外，耦合模式比较计划第6阶段的各种模式对东欧热浪趋势的再现很大程度上取决于模拟的欧亚大陆AT变化，这突出了AT变化对热浪模拟和预测的潜在重大影响。
