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The Stadium Wave - a hypothesized multidecadal climate variability pattern proposed by climate scientist Judith Curry

 The stadium wave refers to a hypothesized multidecadal climate variability pattern proposed by climate scientist Judith Curry and others. It describes a propagating, hemispheric-scale oscillation in climate variables like temperature, sea ice, and atmospheric circulation, primarily in the Northern Hemisphere. The term draws an analogy to a "wave" moving through a stadium crowd, where different regions experience synchronized climate anomalies that shift over time.

Key Features of the Stadium Wave:

1. Multidecadal Oscillation: The stadium wave operates on a roughly 60- to 80-year cycle, involving a sequence of climate shifts that propagate across various regions and systems.
2. Interconnected Systems: It involves interactions among major climate systems, such as:
   • Oceanic oscillations: Like the Atlantic Multidecadal Oscillation (AMO), Pacific Decadal Oscillation (PDO), and North Atlantic Oscillation (NAO).
   • Atmospheric patterns: Jet stream behavior and atmospheric pressure systems.
   • Cryosphere: Sea ice extent in the Arctic and Antarctic.
3. Phased Propagation: The wave manifests as a sequence where anomalies (e.g., warm or cool phases) in one region or system lead or lag those in others, creating a coordinated, wave-like progression. For example, a warm AMO phase might precede changes in Arctic sea ice or Eurasian temperatures.
4. Natural Variability: The stadium wave emphasizes internal climate variability rather than external forcings (like greenhouse gases or solar activity), though it may interact with them.

Mechanism:

The stadium wave suggests that feedback loops between ocean, atmosphere, and ice create a self-sustaining cycle. For instance:

• Changes in ocean temperatures (e.g., AMO shifting to a warm phase) influence atmospheric circulation.
• This alters wind patterns, which affect sea ice distribution.
• Sea ice changes, in turn, influence ocean heat release, feeding back into the system.

Evidence and Research:

• The concept was introduced in a 2013 study by Marcia Wyatt and Judith Curry, published in Climate Dynamics. They analyzed historical climate data and identified a signal where anomalies in temperature, sea ice, and other variables appeared to propagate across the Northern Hemisphere in a predictable sequence.
• The stadium wave is supported by observations of synchronized multidecadal patterns in paleoclimate records, historical temperature data, and climate model simulations, though its exact drivers remain debated.
• It has been used to explain periods of accelerated warming or cooling, such as the mid-20th century cooling period or the early 21st-century Arctic sea ice decline.

Implications:

• Climate Prediction: The stadium wave suggests that natural variability could play a significant role in short- to medium-term climate trends, potentially complicating attribution of changes to human activity.
• Arctic Sea Ice: The wave may contribute to periods of rapid ice loss or recovery, as seen in recent decades.
• Controversy: Some climate scientists are skeptical, arguing the signal may be an artifact of data analysis or that it’s overshadowed by anthropogenic forcing. Others see it as a useful framework for understanding internal variability.

Limitations:

• The stadium wave is primarily a descriptive model based on observed correlations, and its mechanistic underpinnings are not fully understood.
• It focuses on the Northern Hemisphere, with less clarity on its global applicability.
• Distinguishing the wave’s signal from anthropogenic climate change or other forcings remains challenging.