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UP: Fachverband Umweltphysik
UP 2: Clouds and Aerosols
UP 2.8: Talk
Thursday, September 2, 2021, 15:55–16:10, H3
Estimating the impact of tropical volcanic eruptions on the thermal structure of the mesosphere by analyzing HALOE temperature data and UA-ICON simulations — •Sandra Wallis1, Christoph Hoffmann1, Hauke Schmidt2, and Christian von Savigny1 — 1University of Greifswald, Greifswald, Germany — 2Max Planck Institute for Meteorology, Hamburg, Germany
She et al. [1] published a paper in 1998 that analyzed Na lidar temperature profiles and reported an episodic warming of the mesopause region (up to 12.9 K in 100 km altitude) that they attributed to the 1991 Pinatubo eruption. Our study analyses temperature data for the middle atmosphere from the Halogen occultation experiment (HALOE) on the Upper Atmosphere Research Satellite that started its scientific observation 4 months after the eruption. A regression was performed including a volcanic term suggested by She et al., but it did not confirm the significantly higher values reported previously for the lidar measurements. An alternative fit is proposed that approximates the Pinatubo signature with an exponential decay function having an e-folding time of 6 months. We conclude that the HALOE time series probably captures only the decay of a Pinatubo-induced mesospheric warming and that the mesospheric response is more rapid than reported by She et al. The impact of a tropical volcanic eruption on the mesosphere was further investigated by simulations using the upper-atmosphere icosahedral non-hydrostatic (UA-ICON) general circulation model. [1] She et al. Geophys. Res. Lett., 25(4):497-500, 1998.