Impacts of California Wildfires on CO2 and Other Trace Gases

Abstract

Wildfires have broad impacts on the atmosphere, ecology, and society. This study leverages satellite data and chemistry-transport models to analyze the impact of wildfires on trace gases in California during the August-October periods of 2018, 2019, and 2020. During these months, Southern California experiences minimal precipitation, leading to a high Vapor Pressure Deficit, which results in decreased photosynthetic activities. This reduction, combined with increased biomass burning, causes a rise in CO₂ concentrations. Increased CO and CH₄ levels are also seen in TROPOMI retrievals tied to the increase in biomass burning. The CarbonTracker model captures these elevated CO₂ concentrations, though with a reduced amplitude of increased CO₂. Similarly, the GEOS-Chem model successfully simulates high CO levels but underestimates the observed enhancements. These findings will improve the understanding of fire's influence on trace gases and refine future numerical models on surface emissions and transport.