AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Smoke Aerosol Radiocarbon Measurements from Indonesian Fires Provide Evidence for Burning of Millennia-aged Peat
ELIZABETH WIGGINS, Claudia Czimczik, Guaciara dos Santos, Xiaomei Xu, Yang Chen, Jim Randerson, Charles Harvey, Fuu Ming Kai, Liya Yu, NASA
Abstract Number: 461 Working Group: Biomass Combustion: Emissions, Chemistry, Air Quality, Climate, and Human Health
Abstract During the boreal fall of 2015, El Niño induced drought severely exacerbated fires in Indonesia. The fires released an enormous amount of fine particulate matter and created an immense regional smoke cloud that severely degraded air quality for millions of people across Southeast Asia. Although previous studies suggest peat burning was the main contributor to emissions in this region, drought caused by El Niño can also increase agricultural waste burning in plantations and deforestation fires. Significant uncertainty remains with respect to partitioning fire emissions across different landscape sources. In this study, we measured the total carbon concentration and radiocarbon content (Δ14C) of carbonaceous aerosols collected in Singapore, a major city downwind of the fire emissions, to determine the dominant source of these haze-inducing aerosol emissions. The Δ14C of fire derived aerosol was −76 ± 51‰, corresponding to a carbon pool of combusted organic matter with a mean turnover time of 800 ± 420 yr. Our observations indicated that smoke plumes reaching Singapore originated predominantly from the burning of peat (∼85%), and not from agricultural waste burning or deforestation fires. The mean age of the carbonaceous aerosol, which predates the Industrial Revolution, highlights the importance of improving peatland fire management during future El Niño events for meeting climate mitigation and air quality commitments.