Alpine-wide climate indices from reanalyses and EURO-CORDEX projections for different Global Warming Levels

This data set contains calculated and aggregated climate indices for Reanalysis and EURO-CORDEX data on Global Warming Levels (GWLs) for the Alpine Space. Data The reanalysis data used was CERRA (Ridal, et al. 2024) and ERA5 (Hersbach, et al. 2020) on a daily basis. CERRA was used for precipitation, temperature and wind related indices, while drought and heat-drought compound indices are based on a downscaled version of ERA5 from the ADO project (https://www.alpine-space.eu/project/ado/). EURO-CORDEX (Jacob, et al. 2014) data is listed in Tab. 1 and includes two different Regional Climate Models that are driven by 5 to 6 different Global Climate Models. Only the scenario RCP8.5 has been used, because it contains the most Global Warming Levels out of all scenarios. All data was reprojected to the Alpine Space projection EPSG:32632. The period 1991 to 2020 has been used as historical reference for the reanalysis data. For EURO-CORDEX data, the GWL +1°C has been used as reference. Table 1: Models from EURO-CORDEX that have been used to calculate climate indices. Regional Climate Model Global Climate Model Ensemble Member COSMO-crCLIM-v1-1 CNRM-CM5 r1i1p1 COSMO-crCLIM-v1-1 EC-EARTH r1i1p1 COSMO-crCLIM-v1-1 EC-EARTH r3i1p1 COSMO-crCLIM-v1-1 EC-EARTH r12i1p1 COSMO-crCLIM-v1-1 HadGEM2-ES r1i1p1 COSMO-crCLIM-v1-1 MPI-ESM-LR r1i1p1 COSMO-crCLIM-v1-1 MPI-ESM-LR r2i1p1 COSMO-crCLIM-v1-1 MPI-ESM-LR r3i1p1 COSMO-crCLIM-v1-1 NorESM1-M r1i1p1 RCA4 CNRM-CM5 r1i1p1 RCA4 EC-EARTH r1i1p1 RCA4 EC-EARTH r3i1p1 RCA4 EC-EARTH r12i1p1 RCA4 HadGEM2-ES r1i1p1 RCA4 MPI-ESM-LR r1i1p1 RCA4 MPI-ESM-LR r2i1p1 RCA4 MPI-ESM-LR r3i1p1 RCA4 IPSL-CM5A-MR r1i1p1 RCA4 NorESM1-M r1i1p1 Methods Climate indices (see Tab. 2) were first calculated on either an annual, or seasonal basis and are then averaged over different GWLs given by Hauser et al. (2022), however the therein 20-year GWL periods were extended by 5 years in each direction, such that the used GWLs here span 30 years. All projected changes for each GWL are calculated as differences, either absolute or relative, with respect to the 30-year period correspoding to GWL 1°C. Projected changes are calculated for each EURO-CORDEX simulation and are then reported as ensemble percentiles. The following percentiles are contained: 5, 25, 50, 75, 95. Table 2: Climate indices calculated, containing the name, abbreviation and use-case: Climate index name Abbreviation Use-case Maximum 1-day precipitation Rx1d Extreme 1-day precipitation intensity Maximum 3-day precipitation Rx3d Extreme multi-day precipitation intensity Number of days with 1-day precipitation exceeding the 97th percentile R97pN_1d Extreme 1-day precipitation frequency Sum of 1-day precipitation exceeding the 97th percentile R97pTOT_1d Extreme 1-day precipitation cumulative intensity Number of days with 3-day precipitation exceeding the 97th percentile R97pN_3d Extreme multi-day precipitation frequency Sum of 3-day precipitation exceeding the 97th percentile R97pTOT_3d Extreme multi-day precipitation cumulative intensity Convective indicator orange warning conv_ind_orange Extreme convective precipitation Convective indicator red warning conv_ind_red Very extreme convective precipitation Maximum 1-day wind speed WSx1d Extreme wind speed intensity Number of days with 1-day wind speed exceeding the 97th percentile WS97pN_1d Extreme wind speed frequency Mean of maximum wind speed for days exceeding the 97th percentile WS97pMEAN_1d Wind speed on very windy days Number of days with extreme 3-day precipitation and 1-day wind speed maximum RWS97pN_3d Compound extreme precipitation and wind frequency One-month drought peak intensity SPEI1_int Peak intensity of one-month drought One-month drought frequency SPEI1_freq Frequency of one-month severe drought conditions Three-month drought peak intensity SPEI3_int Peak intensity of three-month drought Three-month drought frequency SPEI3_freq Frequency of three-month severe drought conditions Heatwave days HWD Heatwave frequency Heatwave magnitude HWM Heatwave intensity Magnitude of compound one-month drought and heatwave events CDHW_1 Compound heatwave and one-month drought magnitude Magnitude of compound three-month drought and heatwave events CDHW_3 Compound heatwave and three-month drought magnitude Visualization and more detailed information The data can be viewed interactively via a WebGIS platform, which also contains more information about data processing and index definitions: https://cct.eurac.edu/x-risk-cc Acknowledgements The research leading to these results has received funding from Interreg Alpine Space Program 2021-27 under the project number ASP0100101, “How to adapt to changing weather eXtremes and associated compound and cascading RISKs in the context of Climate Change” (X-RISK-CC). References Hauser, M., Engelbrecht, F., & Fischer, E. M. (2022). Transient global warming levels for CMIP5 and CMIP6 (v0.3.0). Zenodo. https://doi.org/10.5281/zenodo.7390473 Hersbach, H., Bell, B., Berrisford, P., et al. (2020). The ERA5 global reanalysis. Q. J. R. Meteorol. Soc., 146, 1999–2049. https://doi.org/10.1002/qj.3803 Jacob, D., Petersen, J., Eggert, B., Alias, A., Christensen, O.B., Bouwer, L.M., Braun, A., Colette, A., Déqué, M., Georgievski, G. and Georgopoulou, E., (2014). EURO-CORDEX: new high-resolution climate change projections for European impact research, Reg. Environ. Change, 14, 563-578. https://doi.org/10.1007/s10113-013-0499-2 Ridal, M., Bazile, E., Le Moigne, P., Randriamampianina, R., Schimanke, S., Andrae, U., et al. (2024). CERRA, the Copernicus European Regional Reanalysis system, Quarterly Journal of the Royal Meteorological Society, 150(763), 3385–3411. https://doi.org/10.1002/qj.4764 Changelog Version 1.0.1: The convective indicator files were reuploaded with rescaled values and updated units. In this version the values have been divided by 100 and are hence provided as "Expected number of events per year" instead of cumulative [%] values per year.