Intense mid-latitude cyclones are one of the main weather hazards affecting Western Europe. They are associated with strong wind gusts and heavy precipitation, which can lead to widespread wind damage and flooding. It is therefore important to understand how mid-latitude cyclones may change in a warming climate, in order to better predict future weather risks. This project investigates the role of diabatic processes associated with extratropical cyclones, with a focus on windstorms in the Atlantic-European sector. In the first phase of the project, CyclEx analyzed how the storm intensity under climate change conditions depends on model resolution based on idealized ICON simulations. Results show that while diabatic contributions increase in a warmer world, this is compensated by other factors, leading to only very minor changes in terms of cyclone intensity (Chen et al. 2024). However, there are clear indications of an enhancement of the associated precipitation and partially also of wind gust in a warmer climate.

In the second phase, CyclEx has two focal parts. In the first part, extreme mid-latitude cyclones are analyzed in CMIP6 global climate models and the changes in environmental conditions are analyzed. In the second part, recent historical events are simulated in ICON with present and warmer climate conditions (2K, 3K, 4K global warming levels and different moisture changes) using the pseudo-global warming approach at different model resolutions. These two parts enable us to better understand and quantify the role diabatic heating in the present-day climate and under future conditions. In particular, we aim to better understand (1) the cyclone dynamics under global climate change, (2) the relative impact of environmental and diabatic processes on the cyclone scale and (3) the possible scale dependency of the relevant physical processes.

Website: CYCLEX

Institution: Institute for Meteorology and Climate Research, Karlsruhe Institute of Technology

Contact: Svenja Christ, Julian Quinting, Joaquim Pinto