Science project 4: Volcanic impacts on atmospheric dynamics (VolDyn)
VolDyn investigates the impact of volcanic eruptions on the dynamic of the atmosphere with a specific focus on the mesosphere region (approximately 50-90 km). Phase I already successfully used a model simulations that included the atmosphere up to the lower thermosphere. These simulations indicated that a strong tropical volcanic eruption of about twice the size of the infamous 1991 Pinatubo eruption could significantly disturb the temperature in the upper mesosphere. Phase II will now systematically explore the sensitivity of these dynamic effects on selected characteristics of the eruption, such as the emitted SO2 mass, the injection height, latitude or season.
Furthermore, we plan to simulate the aforementioned 1991 Pinatubo eruption as realistic as possible by nudging the atmosphere to reanalysis data and using a realistic volcanic forcing. This will allow us to not only make a qualitative but also a quantitative comparison with existing observations - something that is not possible for other well-studied historic eruptions such as the ones of Tambora or Krakatau.
Finally, we want to simulate the transport of volcanic H2O to the polar summer mesopause in order to understand the experimentally observed impact of volcanic eruptions on noctilucent clouds. VolDyn will focus on the so-called “direct pathway” where a volcanic eruption injects water vapour directly into the stratosphere - a mechanism that was last observed during the massive eruption of the submarine Hunga Tonga Hunga Ha'apai volcano in January 2022.
Participants: Sandra Wallis (PI, University of Greifswald), Hauke Schmidt (PI, MPI-M), Christian von Savigny (Co-I, University of Greifswald), Moritz Günther (PhD student, MPI-M)
Wallis, S., Hoffmann, C. G., and von Savigny, C.: Estimating the impact of the 1991 Pinatubo eruption on mesospheric temperature by analyzing HALOE (UARS) temperature data, Ann. Geophys., 40, 421–431, doi.org/10.5194/angeo-40-421-2022, 2022.
Azoulay, A., Schmidt, H., and Timmreck, C.: The Arctic polar vortex response to volcanic forcing of different strengths, J. Geophys. Res., 126, e2020JD034450, doi.org/10.1029/2020JD034450, 2021.
Günther, M., H. Schmidt, C. Timmreck and M. Toohey, Climate feedback to stratospheric aerosol forcing explained by pattern effect, submitted to Journal of Climate, 2022