The Climatology of Elevated Stratopause Events in the UA‐ICON Model and the Contribution of Gravity Waves

Abstract

The upper boundary of the stratosphere, the stratopause, is sensitive to the increasing concentrations of greenhouse gases (GHG) and is considered an independent and novel indicator of GHG-induced climate change (Olivero & Thomas, 2001;Pisoft et al., 2021;Rind et al., 1998). Both space-and ground-based observations indicate a robust stratospheric temperature decrease of about 1-3 K over the last four decades ( -2018( , Steiner et al. (2020a), including a near-global cooling near the stratopause (Steiner et al., 2020b). Associated with such a temperature decrease, Pisoft et al. ( 2021) estimated a global decrease in stratopause height and stratospheric thickness for the future climate under increasing concentration of GHG. Stratopause height trends are crucial to correctly understand and attribute changes in dynamics and tracer transport, and moreover, they may affect satellite orbits (Schrøder et al., 2007). It is therefore of interest to study the characteristics of the stratopause (e.g., its height and temperature) and understand the mechanisms influencing it. While in low and mid-latitudes, the