scClim

Go to scClim project website

A Sinergia project funded by the Swiss National Science Foundation

Socio-economic impacts of weather phenomena in a changing climate are a concern for government agencies, industry and the public, on time scales from hours (warnings) to decades (adaptation, long-term strategic planning). This project focuses on thunderstorm-related severe weather, in particular hail, one of the main weather-related damage drivers in Central Europe for agricultural crops and infrastructure, and related impacts today and in future.

The project brings together expertise in complementary areas to establish a seamless model chain from the simulation of thunderstorms to the quantification of hail impacts in Switzerland, namely: (1) very high-resolution weather and climate modeling, (2) detailed hail track analysis from radar observations, and (3) the integration of process-based model components to provide probabilistic quantification of hail risks and sector-specific impacts on agriculture, buildings and cars. Addressing hail damage is challenging for at least two main reasons: First, hail is related to severe thunderstorms, one of the most complex atmospheric phenomena due to its small spatial scale, vigorous development and the intricate physical interactions. And second, hail damage occurs in various sectors and its quantification requires detailed knowledge about vulnerability and exposure with high spatial and temporal resolution. In order to address these challenges, the scClim project makes use and exploits the synergies of the newest generation of kilometer-scale weather and climate models on GPU-based supercomputing systems (which explicitly represent the essential dynamics of thunderstorms), of a unique observation based hail track climatology for Switzerland, and of the impact modeling platform CLIMADA that integrates multi-sectoral damage assessment components.

In order to achieve its interdisciplinary objectives, scClim is structured in five strongly interconnected subprojects led by scientists from ETH Zurich, University of Bern and Agroscope, and it includes partners and their expertise from MeteoSwiss and industry. Subproject A integrates modules developed in all subprojects, engages in a close dialogue with key stakeholders and expands the open-source and -access impact modeling platform CLIMADA to cover hail risk in Switzerland for insurance and agriculture. This enables testing the potential of impact-based warnings on weather timescales and to obtain insights in the future evolution of hail storms in a changing climate, which is essential to inform sectoral adaptation strategies to strengthen societal resilience against hail risk also on longer timescales. Subproject B uses the COSMO model (with a built-in hail diagnostic) and develops a tracking tool for hail cells and their characteristics to investigate hail in ensemble simulations for specific events and in present-day and near-future (i.e., mid-century) climate simulations. Subproject C combines observations and model results to validate simulated hail cell track behavior in complex topography, to quantify the Lagrangian evolution of cell characteristics, and to identify drivers of inter-annual hail variability and changes in seasonality. Subproject D develops model components that integrate updated crop-hail damage functions and algorithms for computing impacts on crop development , and subproject E delivers model components for buildings and cars. Both D and E build on B and C also to test the framework in the proposed case studies as well as for assessing to assess the implications of climate change on for future hail risk. This approach constitutes a paradigm-shift in the use of meteorological understanding and modeling capabilities for societally relevant warnings and scenarios about high-impact weather events in a changing climate in a region with complex topography like Switzerland.