4. Planetary and Local Winds
Case Study 1: Shifting Trade Winds and Their Impact on Global Climate
Geographical Thought & Perspectives:
- Halley’s Theory of Atmospheric Circulation (1686) – Equatorial heating drives global wind systems.
- Walker’s Circulation Model (1924) – Large-scale atmospheric circulation in the tropics.
- Anthropogenic Climate Change (IPCC, 1988–Present) – Human-induced disruptions in wind patterns.
Models/Theories/Laws:
- Three-Cell Model (Hadley, Ferrel, Polar Cells) – Large-scale atmospheric circulation.
- Trade Wind Variability Model – Changes in equatorial wind strength due to ocean-atmosphere interactions.
- El Niño-Southern Oscillation (ENSO) Model – Oceanic temperature anomalies affecting wind patterns.
Recent Data:
- Trade Wind Weakening: Observed reduction in easterly trade wind strength by ~15% in the Pacific (NOAA, 2024).
- ENSO Influence: Strong El Niño event disrupted normal trade wind circulation.
- Satellite Observations: ESA confirms wind anomalies over the Atlantic and Pacific.
Spatial Variation:
- Pacific Ocean: Weakening trade winds affecting ocean currents.
- Atlantic Ocean: Increased variability in wind-driven upwelling zones.
Temporal Variation:
- Historical Trends: Trade wind shifts accelerating since 2000.
- Future Projections: Expected intensification due to climate change.
Source:
- Nature Climate Change: “Trade Wind Variability and Climate Impacts”
Insight:
Shifting trade winds validate atmospheric circulation models, influencing ocean currents and global climate patterns.
Case Study 2: Rokko-Oroshi Local Wind in Japan (2023)
Geographical Thought & Perspectives:
- Dynamic Climatology (Rossby, 1940s) – Planetary waves influence local wind systems.
- Regional Climate Variability (Lorenz, 1963) – Chaos theory in atmospheric circulation.
- Mountain Wind Systems (Defant, 1951) – Downslope windstorm mechanisms.
Models/Theories/Laws:
- Bora-Type Downslope Windstorm Model – Strong winds due to mountain-wave breaking.
- Hydraulic Jump Theory – Transition from subcritical to supercritical airflow.
- Doppler Lidar Observations – Real-time wind tracking.
Recent Data:
- Rokko-Oroshi Wind Event: Strong downslope winds observed in Kobe, Japan.
- Wind Speed: Recorded at 15–20 m/s, causing infrastructure disruptions.
- Numerical Simulations: WRF model confirms mountain-wave breaking.
Spatial Variation:
- Kobe, Japan: Strong winds originating from the Rokko Mountains.
- Surrounding Areas: Wind effects observed in urban regions.
Temporal Variation:
- Historical Trends: Rokko-Oroshi events recorded over decades.
- Future Projections: Expected intensification due to climate variability.
Source:
- Royal Meteorological Society: “Spatial Structure of Local Winds ‘Rokko-Oroshi’”
Insight:
Rokko-Oroshi validates local windstorm models, demonstrating mountain-induced airflow dynamics.
