Trends in stratospheric fluorine species during the period 2004-2018.
Linear trends in stratospheric fluorine species during the period 2004-2018 (parts per trillion per year) based on trajectory calculations using ERA5 reanalysis winds. The asymmetric trends between the Northern Hemisphere and Southern Hemisphere reflect hemispheric variability in the transport circulation. Credit: Prignon et al. [2021], Figure 6L
Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: Journal of Geophysical Research: Atmospheres

The distribution of long-lived constituents in the stratosphere is related to the Brewer-Dobson circulation and its variability. Prignon et al. [2021] investigate stratospheric circulation changes over the past 20 years deduced from ground-based and satellite observations and model simulations of long-lived fluorine species, which primarily originate from anthropogenic emissions.

Transport model calculations based on reanalysis wind fields show good agreement with observed fluorine changes. Results highlight that fluorine species are accumulating faster in the northern hemisphere than in the southern hemisphere due to interhemispheric differences in the Brewer-Dobson transport circulation. Short-term interannual variations in the circulation are also evident, although with detailed differences in results based on separate reanalyses. These results help understand and constrain future projections of stratospheric circulation changes in chemistry-climate models.

Citation: Prignon, M., Chabrillat, S., Friedrich, M., Smale, D., Strahan, S. E., Bernath, P. F., et al. [2021]. Stratospheric fluorine as a tracer of circulation changes: Comparison between infrared remote-sensing observations and simulations with five modern reanalyses. Journal of Geophysical Research: Atmospheres, 126, e2021JD034995.

—William J. Randel, Editor, JGR: Atmospheres

Text © 2021. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.