Reconciling long-term stratospheric circulation changes from ERA5 and CCMI2
- 1Forschungszentrum Juelich, Institute of Energy and Climate Research Stratosphere (IEK-7), Juelich, Germany (m.diallo@fz-juelich.de)
- 2Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany
- 3Department of Atmospheric Physics, Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
- 4Institute for Meteorology, Leipzig University, Stephanstr. 3, 04103 Leipzig, Germany
- 5Institute for Atmospheric and Environmental Research, University of Wuppertal, Wuppertal, Germany
- 6Department of Meteorology, University of Reading, Reading, UK.
Climate models predict a global acceleration of the stratospheric Brewer-Dobson circulation (BDC) induced by rising greenhouse gas (GHG) levels. However, this predicted strengthening of the BDC has not yet been compared with long-term observations, due to the scarcity of long-term observation records.
The recent release of ERA5 long-term reanalysis data covering the period from 1950 to the present day offers new opportunities to assess the robustness of the projected BDC acceleration. These observation-based data make it possible to assess the ability of models to capture the impact of natural variability such as the Quasi- Biennial Oscillation (QBO), the El Nino Southern Oscillation (ENSO), the solar cycle, stratospheric volcanic aerosols and the Pacific Decadal Oscillation (PDO), on circulation changes and their interaction.
In this presentation, I will review our knowledge of the dynamical mechanisms explaining changes in the BDC over the period 1960-2018 using ERA5 and CCMI-2. I will then highlight the impact of climate variability modes (e.i. QBO, ENSO, Solar, volcanoes and PDO) and their interaction on the BDC. Finally, I will discuss the robustness and main reasons for differences between modern reanalyses and climate models in the BDC changes.
How to cite: Diallo, M. A., Eichinger, R., Iglesias-Suarez, F., Kuchař, A., and Hegglin, M. I.: Reconciling long-term stratospheric circulation changes from ERA5 and CCMI2, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18226, https://doi.org/10.5194/egusphere-egu24-18226, 2024.
