10.48364/ISIMIP.982724.3 Stefan Lange Stefan Lange 0000-0003-2102-8873 Dánnell Quesada-Chacón Dánnell Quesada-Chacón 0000-0001-5700-1846 Matthias Mengel Matthias Mengel 0000-0001-6724-9685 Simon Treu Simon Treu 0000-0002-7001-5983 Matthias Büchner Matthias Büchner 0000-0002-1382-7424 ISIMIP Repository 2025 EARTH SCIENCE > ATMOSPHERE Matthias Büchner Matthias Büchner 0000-0002-1382-7424 Jochen Klar Jochen Klar 0000-0002-5883-4273 Lisa Novak Lisa Novak 0009-0003-5086-1079 Stefanie Heinicke Stefanie Heinicke 0000-0003-0222-5281 Matthias Mengel Matthias Mengel 0000-0001-6724-9685 Christian Otto Christian Otto 0000-0001-5500-6774 Franziska Piontek Franziska Piontek 0000-0003-4305-7552 Dánnell Quesada-Chacón Dánnell Quesada-Chacón 0000-0001-5700-1846 Christopher P.O. Reyer Christopher P.O. Reyer 0000-0003-1067-1492 Inga Sauer Inga Sauer 0000-0002-9302-2131 Jacob Schewe Jacob Schewe 0000-0001-9455-4159 Jan Volkholz Jan Volkholz 0000-0002-2533-3739 Martin Park Martin Park 0000-0002-2467-3256 Katja Frieler Katja Frieler 0000-0003-4869-3013 Potsdam Institute for Climate Impact Research (PIK) 03e8s1d88 2025-10-23 en Input dataset https://www.isimip.org https://protocol.isimip.org https://www.isimip.org/gettingstarted/input-data-bias-adjustment/details/80/ https://doi.org/10.5194/gmd-14-5269-2021 https://doi.org/10.5194/essd-12-2097-2020 https://doi.org/10.1002/qj.776 https://doi.org/10.1002/qj.3803 https://doi.org/10.1002/qj.3598 https://doi.org/10.1175/JCLI-D-20-0505.1 https://doi.org/10.5194/gmd-12-3055-2019 https://doi.org/10.5281/zenodo.5776126 http://dx.doi.org/10.20783/DIAS.501 https://doi.org/10.48364/ISIMIP.342217 https://doi.org/10.48364/ISIMIP.982724.2 1.3 CC0 1.0 Universal Public Domain Dedication This data set provides atmospheric climate input data to be used as input data for ISIMIP3a (www.isimip.org, Frieler et al. 2023, in prep.). We provide four factual climate input datasets for ISIMIP3a: GSWP3-W5E5, 20CRv3-W5E5, 20CRv3-ERA5, and 20CRv3. All of them have daily temporal and 0.5° spatial resolution. Their temporal coverage varies, with GSWP3-W5E5 and 20CRv3-W5E5 covering 1901-2019, while 20CRv3-ERA5 and 20CRv3 cover 1901-2021 and 1901-2015, respectively. For every factual dataset (obsclim) we provide an associated counterfactual dataset (counterclim) covering the same time period, 100 years worth of climate data to be used for model spin-up (spinclim), and 50 years worth of climate data for the transition from spinclim to counterclim or obsclim (transclim).<br>Version 1.1 fixes missing values in GSWP3-W5E5 snow fall input data (see https://data.isimip.org/caveats/26/).<br>Version 1.2 adds extractions of grid cell data for different lake sites.<br>Version 1.3 adds the years 2022-2024 for 20CRv3-ERA5 and obsclim. The transclim data are identical to the last 50 years of the associated spinclim data. The spinclim data are identical to the first 100 years of the associated counterclim data. The counterclim data are a detrended version of the associated obsclim data, where the detrending is done using version 1.1 of the ATTRICI method (Mengel et al. 2021). In the following we briefly describe the obsclim datasets:<br>The GSWP3-W5E5 dataset is based on GSWP3 v1.09 (Kim 2017) and W5E5 v2.0 (Cucchi et al. 2020, Lange et al. 2021). The GSWP3 dataset is a dynamically downscaled and bias-adjusted version of the Twentieth Century Reanalysis version 2 (20CRv2; Compo et al. 2011). The W5E5 dataset is a bias-adjusted version of the latest version of the European Reanalysis (ERA5; Hersbach et al. 2020). For GSWP3-W5E5, we combine W5E5 for the time period 1979-2019 with GSWP3 bias-adjusted towards W5E5 for the time period 1901-1978. The bias adjustment is done using ISIMIP3BASD v2.5.1 (Lange 2019, 2021) in order to reduce discontinuities at the 1978/1979 transition. For more details see Mengel et al. (2021).<br>The 20CRv3-W5E5 dataset is based on W5E5 v2.0 and ensemble member 1 of the Twentieth Century Reanalysis version 3 (20CRv3; Slivinski et al. 2019, 2021) interpolated to 0.5° spatial resolution. For 20CRv3-W5E5, we combine W5E5 for the time period 1979-2019 with 20CRv3 bias-adjusted (using ISIMIP3BASD v2.5.1) towards W5E5 for the time period 1901-1978.<br>The 20CRv3-ERA5 dataset is created in the same way as 20CRv3-W5E5, but using ERA5 instead of W5E5 for the time period 1979-2021, and also as the bias adjustment target for the time period 1901-1978.<br>The 20CRv3 dataset is ensemble member 1 of 20CRv3 interpolated to 0.5° spatial resolution but not bias-adjusted to any other dataset. global -179.5 179.5 -89.5 89.5