Quantifying the Imprints of Stratospheric Contributions to Interhemispheric Differences in Tropospheric CFC‐11, CFC‐12, and N 2 O Abundances
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10.1029-2021GL093700.pdf
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Author(s)
Lickley, Megan
Solomon, Susan
Kinnison, Doug
Krummel, Paul
Mühle, Jens
O'Doherty, Simon
Prinn, Ronald
Rigby, Matthew
Stone, Kane A.
Wang, Peidong
Date Issued
July 15, 2021
Journal
Geophysical Research Letters
Publisher
American Geophysical Union (AGU)
Citation
Lickley, M., Solomon, S., Kinnison, D., Krummel, P., Mühle, J., O’Doherty, S., et al. (2021). Quantifying the imprints of stratospheric contributions to interhemispheric differences in tropospheric CFC-11, CFC-12, and N2O abundances. Geophysical Research Letters, 48, e2021GL093700.
Version
Author's final manuscript
Abstract
For trace gases destroyed in the stratosphere, mass flux across the tropopause can substantially influence observed surface hemispheric differences (NH-SH). Here, we quantify associations between observed stratospheric and tropospheric NH-SH growth rate anomalies of CFC-11, CFC-12, and N2O. We employ a chemistry climate model along with satellite and global surface station observations. Our model explains 60% of observed N2O NH-SH growth rate variability from 2005 to 2019, compared to 30% for CFC-11% and 40% for CFC-12, supporting evidence that unexpected anthropogenic emissions caused sustained positive NH-SH anomalies in these CFCs from 2012 to 2017. Between 2012 and 2015, the observed CFC-11 NH-SH difference grew by 1.7 ppt; our model explains 0.5 ± 0.1 ppt of this growth, but not the duration. Our model suggests that in the absence of further emission anomalies, new NH-SH positive tracer anomalies should have occurred in 2020, and predicts small negative anomalies in 2021.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Massachusetts Institute of Technology. Center for Global Change Science
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DOI of Published Version
https://doi.org/10.1029/2021gl093700
