Abstract:Waveguide teleconnections are quasi-stationary planetary waves propagating along the jet stream waveguide. They play an essential role in the maintenance and evolution of atmospheric circulation, and their abnormal activities are often associated with extreme weather and climate events. Studying the variation and mechanism of waveguide teleconnections at different timescales can not only deepen our understanding of the dynamics of atmospheric circulation but also serve as a scientific basis for weather forecasting, climate prediction, and even climate projection at corresponding timescales. According to the dynamical property of the jet stream waveguide, the atmospheric waveguide can be divided into the subtropical jet waveguide, which is maintained essentially by the barotropic effect, and the polar front jet waveguide, which is primarily maintained by the baroclinic effect. This paper focuses on the waveguide teleconnections in the boreal summer over the Eurasian region, when and where waveguide teleconnections are the most active. It first reviews the history and theory of waveguide teleconnection and then summarizes some recent advances in waveguide teleconnections along the subtropical jet and polar front jet, including their formation conditions, dynamic mechanisms, climate impacts, and future changes. Finally, it discusses some possible issues that deserve future investigation.