An apparent increase in the frequency of summer temperature extremes over northern Eurasia has been observed in the past decade. Some of these high-impact events were associated with amplified wave-like atmospheric patterns embedded in the polar front jet, such as the heatwave that hit Central Europe in June 2019 and East Asia in 2023. In this talk, we will show that the waveguide effect of the polar front jet facilitates strong planetary wave activity and waveguide teleconnections over northern Eurasia. The amplified wave activity and waveguide teleconnections will lead to enhanced temperature extremes over northern Eurasia. Months with extreme temperatures over northern Eurasia generally have amplified wave activity along the polar front jet, whereas months with near-average temperatures tend to have attenuated wave activity. Waveguide teleconnections are particularly amplified during extremely hot and cold summer months over eastern Europe and western Russia. The results are consistent in observations, reanalysis, and large-ensemble simulations from multiple climate models, highlighting the important role of waveguide teleconnections along the polar front jet in generating regional temperature extremes over northern Eurasia.

高温热浪,动力学,遥相关,气候变化