Reconstruction of Paleofire Emissions Over the Past Millennium From Measurements of Ice Core Acetylene

Acetylene is a short-lived trace gas produced during combustion of fossil fuels, biomass, and biofuels. Biomass burning is likely the only major source of acetylene in the preindustrial atmosphere, making ice core acetylene a powerful tool for reconstructing paleofire emissions. Here we present a 2,...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Nicewonger, Melinda R, Aydin, Murat, Prather, Michael J, Saltzman, Eric S
Format: Article in Journal/Newspaper
Language:unknown
Published: eScholarship, University of California 2020
Subjects:
Online Access:https://escholarship.org/uc/item/3m42490x
https://escholarship.org/content/qt3m42490x/qt3m42490x.pdf
https://doi.org/10.1029/2019gl085101
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Summary:Acetylene is a short-lived trace gas produced during combustion of fossil fuels, biomass, and biofuels. Biomass burning is likely the only major source of acetylene in the preindustrial atmosphere, making ice core acetylene a powerful tool for reconstructing paleofire emissions. Here we present a 2,000-year atmospheric record of acetylene reconstructed from analysis of air bubbles trapped in Greenland and Antarctic ice cores and infer pyrogenic acetylene emissions using a chemistry transport model. From 0 to 1500 CE, Antarctic acetylene averages 36±1pmolmol−1 (mean±1 SE), roughly double the annual mean over Antarctica today. Antarctic acetylene declines during the Little Ice Age by over 50% to 17±2pmolmol−1 from 1650 to 1750 CE. Acetylene over Greenland declines less dramatically over the same period. Modeling results suggest that pyrogenic acetylene emissions during 1000–1500 CE were sustained at rates significantly greater than modern day and declined by over 50% during the 1650–1750 CE period.