Dewettinck et al. (2026) Evaluation of the ALARO1-SFX (CY43T2) regional climate model over Belgium across different resolutions

Identification

• Journal: Geoscientific model development
• Year: 2026
• Date: 2026-08-25
• Authors: Wout Dewettinck, Hans Van de Vyver, Daan Degrauwe, Rafiq Hamdi, Michiel Van Ginderachter, Bert Van Schaeybroeck, Kwinten Van Weverberg, Kobe Vandelanotte, Steven Caluwaerts, Piet Termonia
• DOI: 10.5194/gmd-19-7911-2026

Research Groups

• Department of Physics and Astronomy, Ghent University (UGent), Belgium
• Royal Meteorological Institute of Belgium (RMIB), Brussels, Belgium
• Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China
• Department of Geography, Ghent University (UGent), Ghent, Belgium

Short Summary

This study evaluates the ALARO1-SFX regional climate model over Belgium across different resolutions. The results indicate that higher resolutions improve temperature and precipitation biases relative to the 25 km simulation.

Objective

• Evaluate the performance of the ALARO1-SFX regional climate model at different resolutions (25, 12.5, and 4 km) over Belgium.
• Assess the added value of increasing resolution on near-surface temperature and precipitation representation.

Study Configuration

• Spatial Scale: Regional scale over Belgium with a focus on near-surface temperature and precipitation representation.
• Temporal Scale: Long-term continuous climate simulations spanning 32 years from 1 January 1991 to 31 December 2022.

Methodology and Data

• Models used: ALARO1-SFX regional climate model, SURFEX land-surface scheme, and ERA5 reanalysis dataset for boundary conditions.
• Data sources: CLIMATE-GRID (CG) dataset, a Belgian 5 km gridded observational dataset based on interpolated station data.

Main Results

• Higher resolutions (12.5 and 4 km) improve temperature and precipitation biases relative to the 25 km simulation.
• The 4 km resolution provides the best representation of hourly extreme precipitation and its diurnal cycle.
• A dedicated sensitivity experiment isolates the contribution of the SURFEX land-surface scheme, attributing a substantial part of the improvement in near-surface temperature and precipitation to its introduction.

Contributions

• This study provides evidence that increasing model resolution improves the representation of extreme precipitation.
• The findings underscore the added value of convection-permitting modelling for improving diurnal precipitation cycles.

Funding

• This research was funded by [project 1], [project 2], and [project 3].

Citation

@article{Dewettinck2026Evaluation,
  author = {Dewettinck, Wout and Vyver, Hans Van de and Degrauwe, Daan and Hamdi, Rafiq and Ginderachter, Michiel Van and Schaeybroeck, Bert Van and Weverberg, Kwinten Van and Vandelanotte, Kobe and Caluwaerts, Steven and Termonia, Piet},
  title = {Evaluation of the ALARO1-SFX (CY43T2) regional climate model over Belgium across different resolutions},
  journal = {Geoscientific model development},
  year = {2026},
  doi = {10.5194/gmd-19-7911-2026},
  url = {https://doi.org/10.5194/gmd-19-7911-2026}
}