Mountain-wave Induced Polar Stratospheric Clouds with ICON-ART: An Example at the Antarctic Peninsula
- 1Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany (michael.weimer@kit.edu)
- 2Steinbuch Centre for Computing, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
- 3Jülich Supercomputing Centre, Forschungszentrum Jülich, Jülich, Germany
Polar Stratospheric Clouds (PSCs) play a key role in explaining ozone depletion on large
scales as well as on regional scales. Mountain waves can be formed in the lee of a mountain
in a stably stratified atmosphere. They can propagate upwards into the stratosphere and
induce temperature changes in the order of 10 to 15 K. Thus, large PSCs localised around the
mountain ridge can be formed, leading to increased chlorine activation and subsequently to
a larger ozone depletion. It was estimated that 30 % of the southern hemispheric PSCs can
be explained by mountain waves. However, for the direct simulation of mountain-wave
induced PSCs, the mountains have to be represented adequately in global chemistry climate
models which was a challenge in the past due to too low horizontal resolution.
The ICOsahedral Nonhydrostatic (ICON) modelling framework with its extension for Aerosols
and Reactive Trace gases (ART) includes a PSC scheme coupled to the atmospheric chemistry
in the model. The PSC scheme calculates the formation of all three PSC types independently
resulting in the calculation of the heterogeneous reaction rates of chlorine and bromine
species on the surface of PSCs. ICON-ART provides the possibility of local grid refinement
with two-way interaction. With this, the grid around a mountain can be refined so that
mountain waves can be directly simulated in this region with a feedback to the coarser
global resolution.
In this study, we show the formation of mountain-wave induced PSCs with ICON-ART for the
example of a mountain wave event in July 2008 around the Antarctic Peninsula. It is
evaluated with satellite measurements of AIRS and CALIOP and its impact on chlorine and
bromine activation as well as on the ozone depletion in the southern hemisphere are
analysed. We demonstrate that the effect of mountain-wave induced PSCs can be
represented in the coarser global grid by using local grid refinement with two-way
interaction. Thus, this study bridges the gap between directly simulated mountain-wave
induced PSCs and their representation in a global simulation.
How to cite: Weimer, M., Schröter, J., Hoffmann, L., Kirner, O., Ruhnke, R., and Braesicke, P.: Mountain-wave Induced Polar Stratospheric Clouds with ICON-ART: An Example at the Antarctic Peninsula, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2451, https://doi.org/10.5194/egusphere-egu2020-2451, 2020.
