DEUTSCH

Henning Franke

Department Climate Physics
Group Cloud-Wave Coupling
Position Postdoc
phone +49 40 41173-354
Email henning.franke@mpimet.mpg.de
Room B 406

In my research, I investigate how stratospheric dynamics can be realistically represented in the latest generation of atmospheric circulation models — so-called global storm-resolving models. In particular, I focus on the so-called quasi-biennial oscillation (QBO) of the zonal wind in the tropical stratosphere, which is characterized by alternating downward propagating westerly and easterly wind jets.

The stratospheric circulation in general and the QBO in particular are significantly influenced and driven by atmospheric waves of different horizontal wavelengths. A considerable fraction of these waves comprises atmospheric gravity waves, which have very short horizontal wavelengths of sometimes only a little more than 10 km. For this reason, the effects of these gravity waves on the QBO in conventional circulation models, which have a horizontal resolution of about 100 km, had to be considered empirically using so-called gravity wave parameterizations. This has led to large uncertainties in the modeled QBO, as a result of which many questions regarding the role of the QBO in the global climate system and possible changes of the QBO in a warming climate could not yet be answered conclusively. 

Global storm-resolving models offer the possibility to overcome the uncertainties of conventional circulation models by having a much higher horizontal and vertical resolution and thus being able to explicitly simulate deep convection and gravity waves instead of parameterizing them. Accordingly, this modeling approach has great potential to answer important research questions regarding the QBO and stratospheric circulation in general more accurately. However, the simulation of the QBO in such a storm-resolving model is anything but trivial. For this reason, I am investigating which factors are necessary for a successful simulation of the QBO in the storm-resolving model ICON.

H. Franke, M. A. Giorgetta: Toward the direct simulation of the quasi-biennial oscillation in a global storm-resolving model, Journal of Advances in Modeling Earth Systems, https://doi.org/10.1029/2024MS004381, 2024.

H. Franke, P. Preusse, M. A. Giorgetta: Changes of tropical gravity waves and the quasi-biennial oscillation in storm-resolving simulations of idealized global warming, Quarterly Journal of the Royal Meteorological Society, https://doi.org/10.1002/qj.4534, 2023.

I. Quaglia, C. Timmreck, U. Niemeier, D. Visioni, G. Pitari, C. Brühl, S. Dhomse, H. Franke, A. Laakso, G. Mann, E. Rozanov, T. Sukhodolov: Interactive Stratospheric Aerosol models' response to different amounts and altitudes of SO2injections during the 1991 Pinatubo eruption, Atmos. Chem. Phys., https://doi.org/10.5194/acp-23-921-2023, 2023.

M. A. Giorgetta, W. Sawyer, X. Lapillonne, P. Adamidis, D. Alexeev, V. Clément, R. Dietlicher, J. F. Engels, M. Esch, H. Franke, C. Frauen, W. M. Hannah, B. R. Hillman, L. Kornblueh, P. Marti, M. R. Norman, R. Pincus, S. Rast, D. Reinert, R. Schnur, U. Schulzweida, and B. Stevens: The ICON-A model for direct QBO simulations on GPUs (version icon-cscs:baf28a514), Geoscientific Model Development, https://doi.org/10.5194/gmd-15-6985-2022, 2022.

D. K. Weisenstein, D. Visioni, H. Franke, U. Niemeier, S. Vattioni, G. Chiodo, T. Peter, and D. W. Keith: A Model Intercomparison of Stratospheric Solar Geoengineering by Accumulation-Mode Sulfate Aerosols, Atmos. Chem. Phys., https://doi.org/10.5194/acp-22-2955-2022, 2022.

H. Franke, U. Niemeier, D. Visioni: Differences in the quasi-biennial oscillation response to stratospheric aerosol modification depending on injection strategy and species, Atmos. Chem. Phys., https://doi.org/10.5194/acp-21-8615-2021, 2021.

Postdoc, Max Planck Institute for Meteorology (since 2024)

Ph.D. Earth System Sciences, Max Planck Institute for Meteorology (2020 – 2024)
PhD Thesis: The quasi-biennial oscillation in a warming climate
Supervision: Dr. Marco Giorgetta, Dr. Ulrike Niemeier, Prof. Bjorn Stevens

M.Sc. Meteorology, University of Hamburg (2017 – 2020)
Master's Thesis: Stratospheric Injection of Sulfur - Injection of H2SO4 Compared to Injection of SO2
Supervision: Dr. Ulrike Niemeier, Prof. Stefan Bühler
Stay abroad: The University Centre in Svalbard (Longyearbyen, Norway), 2018

B.Sc. Meteorology, University of Hamburg (2014 – 2018)
Bachelor's Thesis: Cloud Correlations in Tropical Convection
Supervision: Dr. Jan O. Härter, Prof. Stefan Bühler
Stay abroad: University of Oklahoma (Norman, USA), 2016

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An oscillating wind system in the tropical stratosphere: future evolution and new projections

The “quasi-biennial oscillation” (QBO) is a well-known wind system characterized by alternating layers of westerly and easterly winds encircling the whole globe that descend through the equatorial stratosphere with a roughly two year periodicity. However, so far it has been still uncertain how the QBO may change due to global warming. A team of scientists led by researcher Henning Franke from the Max Planck Institute for Meteorology...

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Julia Windmiller co-leads the atmospheric measurements on board RV SONNE

On 27 June 2021, after a 10-day quarantine of the participants, the RV SONNE will set off from Emden under the cruise guidance of Prof. Peter Brandt from GEOMAR in Kiel and co-leader Dr. Julia Windmiller from the Max Planck Institute for Meteorology (MPI-M). [...] Julia Windmiller is accompanied by Henning Franke and Katharina Stolla from the department "The Atmosphere in the Earth System" as well as Ilaria Quaglia, who is currently a guest at the MPI-M.

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