EGU General Assembly 2021
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Multi-decadal climate variability in the tropical stratosphere coupled to the Pacific

Fernando Iglesias-Suarez1, Oliver Wild2, Douglas E. Kinnison3, Rolando R. Garcia3, Daniel R. Marsh4,5, Jean-François Lamarque4, Edmund M. Ryan6, Sean M. Davis7, Roland Eichinger1,8, Alfonso Saiz-Lopez9, and Paul J. Young2,10
Fernando Iglesias-Suarez et al.
  • 1Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, Germering, Germany (
  • 2Lancaster Environment Centre, Lancaster University, Lancaster, UK
  • 3Atmospheric Chemistry Observations and Modelling, NCAR, Boulder, CO, USA
  • 4Climate and Global Dynamics Laboratory, NCAR, Boulder, CO, USA
  • 5Faculty of Engineering and Physical Sciences, University of Leeds, Leeds, UK
  • 6Department of Mathematics, University of Manchester, Manchester, UK
  • 7NOAA Chemical Sciences Laboratory, Boulder, CO, USA
  • 8Charles University, Department of Atmospheric Physics, Faculty of Mathematics and Physics, Prague, Czech Republic
  • 9Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, CSIC, Madrid, Spain
  • 10Centre of Excellence for Environmental Data Science, a partnership between Lancaster University and the UK Centre for Ecology and Hydrology, Lancaster, UK

Recent studies have noted that tropical mid-stratospheric ozone decreased in the 1990s and has remained persistently low since. Current analyses suggest that these observations are linked to dynamical processes rather than being chemically-driven, although this has not been fully explored. Using measurements and chemistry-climate model simulations, we show that 50 ± 10% of these observed trends can be accounted for through multi-decadal variability in the Brewer-Dobson circulation (BDC) tied to the Pacific Ocean sea surface temperatures (the Interdecadal Pacific Oscillation, or IPO), via dynamical and chemical couplings. Moreover, accounting for this low frequency variability in the BDC can also help interpret previous observationally-derived changes in that circulation since year 1979. Overall, these findings demonstrate strong links between stratosphere-troposphere variability at decadal time scales and their potential importance for future ozone recovery detection.

How to cite: Iglesias-Suarez, F., Wild, O., Kinnison, D. E., Garcia, R. R., Marsh, D. R., Lamarque, J.-F., Ryan, E. M., Davis, S. M., Eichinger, R., Saiz-Lopez, A., and Young, P. J.: Multi-decadal climate variability in the tropical stratosphere coupled to the Pacific, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-3953,, 2021.


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