ENSO modulates wildfire activity in China

Area of Science:

• Environmental Science
• Climate Science
• Remote Sensing

Background:

• Understanding fire activity in China is crucial due to strict fire suppression policies.
• China's fire dynamics are influenced by regional climate and environmental factors.

Purpose of the Study:

• To present a detailed fire occurrence dataset for China (Wildfire Atlas of China, WFAC; 2005-2018).
• To analyze the drivers of wildfire variability across China.

Main Methods:

• Utilized continuous monitoring from multiple satellites for fire occurrence data.
• Calibrated satellite data against field observations.
• Analyzed spatial and temporal fire patterns and their climatic drivers.

Main Results:

• Wildfires predominantly occur in winter (January-April) and show a decreasing trend after 2007.
• 84% of wildfires are concentrated in subtropical China, with clusters in the southwest and southeast.
• Southeastern China fires linked to low precipitation and high diurnal temperature ranges; southwestern fires to warm conditions enhancing evaporation.
• A fire occurrence dipole between southwest and southeast China is modulated by El Niño-Southern Oscillation (ENSO).

Conclusions:

• The WFAC dataset provides valuable insights into China's wildfire regimes.
• Climate variability, particularly precipitation and temperature, significantly influences wildfire occurrence in subtropical China.
• ENSO plays a role in modulating regional fire patterns.