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 The period 1991 to 2020 has been used as historical reference for the reanalysis data.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.