Variation of lightning-ignited wildfire patterns under climate change

Area of Science:

• Atmospheric Science
• Climate Science
• Wildfire Science

Background:

• Lightning is a primary driver of natural wildfires.
• Long-Continuing-Current (LCC) lightning flashes are identified as key igniters of lightning-ignited wildfires (LIW).
• Previous research indicates shifts in total lightning patterns, but wildfire sensitivity to climate change remains unclear.

Purpose of the Study:

• To investigate space-based measurements of LCC lightning linked to wildfire ignitions.
• To project future LCC lightning occurrence under climate change scenarios.
• To assess the implications for lightning-ignited wildfire risk.

Main Methods:

• Utilized space-based measurements of LCC lightning.
• Applied a novel LCC lightning parameterization model based on thunderstorm updraft strength.
• Generated LCC lightning projections for the 2090s using the Representative Concentration Pathway RCP6.0.

Main Results:

• A projected 41% global increase in LCC lightning flash rates by the 2090s.
• Significant LCC lightning increases anticipated in South America, North America, Central America, Australia, Asia, and Europe.
• Regional variations noted in northern polar forests, with implications for permafrost carbon release.

Conclusions:

• Climate change is projected to increase LCC lightning, a critical wildfire igniter.
• Accurate wildfire projections require lightning schemes that explicitly incorporate LCC lightning.
• Updated modeling is essential for understanding and mitigating future wildfire risks.