Orbital and Millennial Variations in Wildfires Recorded in the East Siberian Arctic Shelf Over the Last Climatic Cycle

Le résumé fourni par la source

Abstract Wildfires and black carbon (BC) are critical to understanding the global carbon cycle and climate change, especially in the rapidly warming Arctic. This study reconstructs high‐intensity wildfire history over the last ∼120 kyr using soot‐BC and stable carbon isotopes from sediment core LV90‐8‐1 on the East Siberian Arctic shelf. Results show that wildfires were suppressed during warm, humid interglacial periods (MIS 5c‐e, MIS 1) due to the dominance of fire‐avoiding forests and low fuel flammability. While during cold, dry glacial periods (MIS 2, MIS 4), wildfire was limited by fuel shortages caused by sparse tundra vegetation. Elevated fire activity during MIS 5a‐b and MIS 3 show millennial‐scale Dansgaard‐Oeschger variations in most cases, with increased wildfires during Interstadials and decreased during Stadials, driven by fuel availability. The study highlights the sensitivity of Arctic wildfire to climate‐vegetation interactions. Under ongoing anthropogenic warming, increased wildfire could accelerate Arctic warming through BC‐albedo positive feedback.

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