RELATIVELY HUMAN — S1E7: "When Weather Gets Stuck"

Episode Description Why does weather get "stuck" in relentless heat domes or catastrophic floods? We discard the outdated idea of the jet stream as a stable "river" of air, exploring it instead as an unstable, wave-channeling gradient boundary skidding over planetary topography. We trace the convergence of four scientific frontiers explaining our changing weather:

1. Climate Dynamics: Arctic amplification weakens the equator-to-pole temperature gradient, altering the atmosphere's waveguide. Quasi-Resonant Amplification (QRA) traps planetary waves, sparking events like the 2021 Pacific Northwest Heat Dome via soil moisture feedbacks. We also explore how Recurrent Rossby Wave Packets (RRWPs) drive extreme Australian heatwaves.
2. Nonlinear Dynamics: We uncover the counterintuitive discovery that persistent atmospheric blocking is actually more chaotic and unstable than normal weather, representing Unstable Periodic Orbits (UPOs) in the atmosphere's high-dimensional phase space.
3. Statistical Mechanics: Ruelle linear response theory allows scientists to predict how a chaotic climate system's statistics shift under continuous greenhouse gas forcing, a breakthrough demonstrated in state-of-the-art coupled models like the MPI-ESM.
4. Prediction Science: The "signal-to-noise paradox" reveals the real atmosphere carries a stronger, more predictable signal than models capture. We discuss how missing dynamics, particularly eddy feedbacks, drive this multi-causal problem, and why atmospheric predictability "flickers" from decade to decade.

From debates over waveguidability to predicting changes in the climate's attractor dimension, we explore the physics of stalling weather.

Citation List

• Ali, S. M., et al. (2022). Recurrent Rossby waves during Southeast Australian heatwaves and links to quasi-resonant amplification and atmospheric blocks. Weather and Climate Dynamics.
• Blackport, R., & Screen, J. A. (2020). Insignificant effect of Arctic amplification on the amplitude of midlatitude atmospheric waves. Science Advances, 6(8).
• De Cruz, L., et al. (2018). Exploring the Lyapunov instability properties of high-dimensional atmospheric and climate models. Nonlinear Processes in Geophysics, 25, 387–412.
• Hardiman, S. C., et al. (2022). Missing eddy feedback may explain weak signal-to-noise ratios in climate predictions. npj Climate and Atmospheric Science, 5(57).
• Lembo, V., Lucarini, V., & Ragone, F. (2020). Beyond Forcing Scenarios: Predicting Climate Change through Response Operators in a Coupled General Circulation Model. Scientific Reports, 10, 8668.
• Li, X., et al. (2024). Role of atmospheric resonance and land-atmosphere feedbacks as a precursor to the June 2021 Pacific Northwest Heat Dome event. Proceedings of the National Academy of Sciences, 121(4).
• Lucarini, V., & Gritsun, A. (2020). A new mathematical framework for atmospheric blocking events. Climate Dynamics, 54, 575–598.
• Weisheimer, A., et al. (2024). The Signal-to-Noise Paradox in Climate Forecasts: Revisiting Our Understanding and Identifying Future Priorities. Bulletin of the American Meteorological Society, 105(3).
• Wirth, V., & Polster, C. (2021). The Problem of Diagnosing Jet Waveguidability in the Presence of Large-Amplitude Eddies. Journal of the Atmospheric Sciences, 78(10).