Document Type
Article
Publication Date
2022
DOI
10.1073/pnas.2117325119
Publication Title
Proceedings of the National Academy of Sciences of the United States of America
Volume
119
Issue
10
Pages
e2117325119 (1-9)
Abstract
Massive Australian wildfires lofted smoke directly into the stratosphere in the austral summer of 2019/20. The smoke led to increases in optical extinction throughout the midlatitudes of the southern hemisphere that rivalled substantial volcanic perturbations. Previous studies have assumed that the smoke became coated with sulfuric acid and water and would deplete the ozone layer through heterogeneous chemistry on those surfaces, as is routinely observed following volcanic enhancements of the stratospheric sulfate layer. Here, observations of extinction and reactive nitrogen species from multiple independent satellites that sampled the smoke region are compared to one another and to model calculations. The data display a strong decrease in reactive nitrogen concentrations with increased aerosol extinction in the stratosphere, which is a known fingerprint for key heterogeneous chemistry on sulfate/H2O particles (specifically the hydrolysis of N2O5 to form HNO3). This chemical shift affects not only reactive nitrogen but also chlorine and reactive hydrogen species and is expected to cause midlatitude ozone layer depletion. Comparison of the model ozone to observations suggests that N2O5 hydrolysis contributed to reduced ozone, but additional chemical and/or dynamical processes are also important. These findings suggest that if wildfire smoke injection into the stratosphere increases sufficiently in frequency and magnitude as the world warms due to climate change, ozone recovery under the Montreal Protocol could be impeded, at least sporadically. Modeled austral midlatitude total ozone loss was about 1% in March 2020, which is significant compared to expected ozone recovery of about 1% per decade.
Original Publication Citation
Solomon, S., Dube, K., Stone, K., ... Bourassa, A., Zawada, D., & Degenstein, D. (2022). On the stratospheric chemistry of midlatitude wildfire smoke. Proceedings of the National Academy of Sciences of the United States of America, 119(10), 1-9, Article e2117325119. https://doi.org/10.1073/pnas.2117325119
ORCID
0000-0002-1255-396X (Bernath)
Repository Citation
Soloman, Susan; Dube, Kimberlee; Stone, Kane; Yu, Pengfei; Kinnison, Doug; Toon, Owen B.; Strahan, Susan E.; Rosenlof, Karen H.; Portmann, Robert; Davis, Sean; Randel, William; Bernath, Peter; Boone, Chris; Bardeen, Charles G.; Bourassa, Adam; Zawada, Daniel; and Degenstein, Doug, "On the Stratospheric Chemistry of Midlatitude Wildfire Smoke" (2022). Chemistry & Biochemistry Faculty Publications. 220.
https://digitalcommons.odu.edu/chemistry_fac_pubs/220
Included in
Atmospheric Sciences Commons, Environmental Chemistry Commons, Fire Science and Firefighting Commons, Organic Chemistry Commons
Comments
This open access article is distributed under a Creative Commons Attribution 4.0 International License (CC BY 4.0)