Regional Climate Model: ALARO-0 model

This data includes spatially-detailed climate projections for Belgium and can be used for climate-change impact assessments (historical and RCP simulations) and analysis of past climate (evaluation simulation). Note that the historical run will, by construction, not correspond to past observations. For further details please contact RMI or cordex@meteo.be.

This dataset has been obtained by dynamical downscaling using the regional climate model ALARO-0 (Termonia et al., 2018a) in the context of the BELSPO-funded project CORDEX.be (Termonia et al, 2018b, www.euro-cordex.be). The downscaling methodology is in line with the guidelines of the Coordinated Regional Downscaling Experiment (CORDEX; Jacob et al. 2014) and follows the climate scenario's RCP2.6, RCP4.5 and RCP8.5 as suggested by the Intergovernmental Panel on Climate Change. The spatial resolution of the data is 4-km and the domain covers a region centered over Belgium. The temporal resolution of the data is daily over long continuous periods. The historical experiment covers the period 1976-2005 and the RCP scenarios cover the period 2007-2100. Precipitation data has undergone thorough validation (Van de Vyver et al., 2021) and investigation (Helsen et al., 2020). The 4-km simulations were performed in a double (one-way) nesting setup where the Belgian domain was nested in an ALARO-0 run over the EURO-CORDEX domain (Berckmans et al, 2021) with a resolution of 0.44° (≃ 50 km) and validated in Giot et al. (2016). Around Europe the latter was forced by the global climate model CNRM-CM5 (historical, RCP 2.6, RCP 4.5, RCP 8.5) that has a resolution of about 1.4° (≃ 155 km) and is part of the Coupled Model Intercomparison Project CMIP5.

Giot et al., 2016. DOI: 10.5194/gmd-9-1143-2016

Helsen et al., 2020. DOI: 10.1007/s00382-019-05056-w

Termonia et al., 2018a. DOI: 10.1016/j.cliser.2018.05.001

Termonia et al., 2018b. DOI: 10.5194/gmd-11-257-2018

Jacob et al., 2014. DOI: 10.1007/s10113-013-0499-2

Van de Vyver et al., 2021. DOI: 10.1175/JAMC-D-21-0004.1

Further info can be found on

https://cordex.org/experiment-guidelines/

http://www.belspo.be/belspo/brain-be/projects/FinalReports/CORDEXbe_FinRep_AD.pdf

Periods:

* present climate: HIST_1975_2005

* future climate, 3 emission scenarios RCP 2.6, RCP 4.5, RCP 8.5: RCP26_2007_2100, RCP45_2007_2100, RCP85_2007_2100

Variables:

1. et0 = Reference Evapotranspiration [kg m-2 s-1]; to get this in mm/day, the data should be multiplied by 60*60*24 = 86400. It is calculated following the FAO method (Allen et al., 1998) using the Penman-Monteith equation for reference (potential) crop evapotranspiration

2. hurs = relative humidity [%]

3. pr = precipitation [kg m-2 s-1]; to get precipitation in mm/day, the data should be multiplied by 60*60*24 = 86400

4. rsds = global solar radiation [W m-2]

5. sfcWind = wind at 10 m [m s-1]

6. tas = near-surface (2 m) air temperature at 2 m [K]

7. tasmax = daily maximum near-surface (2 m) air temperature [K]

8. tasmin = daily minimum near-surface (2 m) air temperature [K]

9. et0 = Reference Evapotranspiration [kg m-2 s-1]; to get this in mm/day, the data should be multiplied by 60*60*24 = 86400