Data accompanying: Loeffel, S., Rupp, P., Kiefer, S., Pinto, J., Birner, T., and Garny, H. (2026). "Quantifying the tropospheric response to individual sudden stratospheric warmings revealed by an ensemble simulation strategy." Weather and Climate Dynamics (WCD) This dataset contains post-processed output from numerical model simulations and ERA5 reanalysis data used in the study. It includes indices describing zonal mean zonal wind and geopotential height anomalies associated with sudden stratospheric warming (SSW) events. The data comprise results from the Event Generating Ensemble and 18 spin-off ensembles, as well as corresponding ERA5-based indices for comparison. Variables include ensemble means and spreads of standardized anomalies and wind indices at key pressure levels. All data are provided in NetCDF format with metadata describing variables and units.eng