Amplification of Waveguide Teleconnections in the Boreal Summer
Hypotheses based on linear waveguide dynamics have been proposed to explain the increasing occurrence of high-amplitude and circumglobal quasi-stationary Rossby wave anomalies, which may lead to persistent and high-impact extreme events in recent boreal summers. It is thus useful to synthesize these hypotheses and to discuss limitations of this simplified dynamical framework for explaining observed features
The hypothesis that climate change can alter the basic circulation states and thereby enhance circumglobal waveguide teleconnections through resonance has been proposed but has not yet been verified with models. On the other hand, recent general circulation model simulations, assisted by linear planetary wave models, indicate that enhanced terrestrial heating associated with the emerging midlatitude aridity can stimulate the jet stream waveguides thus leading to more high-amplitude circumglobal planetary wave events.
There could be circumstances that lead to resonance amplification of waveguide Rossby waves in the boreal summer, but an alternative mechanism that involves terrestrial interactions may be needed to explain such a phenomenon.