Amazon rainforest canopy chemistry study reveals how biomass burning and biogenic emissions influence ozone dynamics

Summary

This scientific study applies the FORCAsT v2 canopy column model to an Amazonian rainforest site to investigate how in-canopy chemistry affects above-canopy concentrations of ozone (O3) and bi-directional exchange of natural compounds. The research, focused on the 2015 El Niño period, finds that biomass burning enhances O3 flux into the canopy, increasing oxidation chemistry and O3 deposition to vegetation. Key findings include: sesquiterpenes enhance O3 chemical loss from ~3% to 10-15% of total in-canopy losses; sesquiterpene canopy escape efficiency varies by 45-55% controlled by O3 oxidation and vertical turbulence; soil NOx escape efficiency (40-50%) is higher than many models suggest with a strong diurnal cycle driving O3 production; and pool-dependent emissions for BVOCs show variability in escape efficiency. The study highlights reactive BVOCs (especially sesquiterpenes) as major sources of uncertainty and emphasizes turbulence's critical role in linking canopy processes to above-canopy atmospheric composition.

Source

bskyAmazon rainforest canopy chemistry study reveals how biomass burning and biogenic emissions influence ozone dynamicsacp.copernicus.org