An Intensified Mode of Variability Modulating the Summer Heat Waves in Eastern Europe and Northern China

This study investigates the leading pattern of Eurasian summer heat waves (HWs) using observed and simulated data sets and reveals an intensified mode of variability that bridges the HWs in eastern Europe (EE) and northern China (NC). The concurrent variability of the HWs in EE and NC is primarily driven by an atmospheric circum-global teleconnection that induces anomalous anticyclones over the two regions. The observed upward trends in EE and NC HW days could be related to the warm sea surface temperatures around Greenland Island, which may weaken the Atlantic westerly jet stream and lead to amplified wave trains at the exit of the jet, resulting in strengthened anticyclones over EE and NC that favor the occurrences of HWs. The Geophysical Fluid Dynamics Laboratory high-resolution atmospheric model fails to simulate the EE and NC HWs, due probably to the model's poor representation of the South Asian summer rainfall. Plain Language Summary Heat waves (HWs) in eastern Europe (EE) and northern China (NC) are found to be bridged via an atmospheric teleconnection, which induces abnormal highs over EE and NC. As a result, the soil conditions in EE and NC become drier and hotter due to the decreased precipitation and increased solar radiation, which favors the occurrences of HWs. The North Atlantic warming may lead to the increases in EE and NC HWs by altering the Atlantic westerly jet stream and associated wave trains. The Geophysical Fluid Dynamics Laboratory high-resolution atmospheric model fails to simulate the EE and NC HWs, due probably to model's poor representation of the South Asian summer rainfall.