Projected changes in extreme winds over Japan from a large-ensemble climate experiment

Area of Science:

• Climatology
• Extreme weather events
• Climate change impacts

Background:

• Extreme winds pose a significant climate hazard in Japan.
• Quantifying the response of extreme winds to global warming levels is crucial for risk assessment.

Purpose of the Study:

• To investigate projected changes in daily maximum 10m wind speeds across Japan under different global warming scenarios.
• To analyze the impact of global warming on hazard-relevant return levels of extreme winds.

Main Methods:

• Utilized the d4PDF large-ensemble dataset for present-day and future climate simulations (+1.5K, +2K, +4K).
• Employed a seasonal piecewise extreme value framework with generalized extreme value (GEV) distributions.
• Calculated annual 5-, 10-, 50-, and 100-year return levels for 311 land grid points.

Main Results:

• Present-day return levels exhibit strong spatial and seasonal variations, with peaks in summer/autumn in southern and coastal areas.
• The 5-year return level shows minimal change across warming levels.
• Significant increases in 50- and 100-year return levels are projected, with greater amplification at higher warming levels (+4K).

Conclusions:

• Extreme wind risk in Japan is projected to amplify under future global warming.
• Southern and coastal regions face a disproportionately higher increase in high-impact wind events.
• Understanding these changes is vital for developing effective climate adaptation and mitigation strategies.