Argüeso et al. (2012) High‐resolution projections of mean and extreme precipitation over Spain using the WRF model (2070–2099 versus 1970–1999)

Identification

• Journal: Journal of Geophysical Research Atmospheres
• Year: 2012
• Date: 2012-05-29
• Authors: Daniel Argüeso, J. M. Hidalgo‐Muñoz, Sonia Raquel Gámiz‐Fortis, María Jesús Esteban‐Parra, Yolanda Castro‐Díez
• DOI: 10.1029/2011jd017399

Research Groups

• Earth Sciences Department, Barcelona Supercomputing Center, Barcelona, Spain
• Projects Department, Technical University of Catalonia, Barcelona, Spain
• Climate Change Unit, Meteorological Service of Catalonia, Barcelona, Spain

Short Summary

This study dynamically downscales global climate projections to a 10 km resolution over the North Western Mediterranean Basin (NWMB) for 1971–2050 to assess temperature and precipitation trends. Results indicate a significant increase in annual mean temperature (up to 1.4 K) and an overall decrease in annual mean precipitation (5–13%), particularly in mountainous regions, while highlighting the improved spatial detail from high-resolution modeling despite persistent uncertainties in seasonal precipitation.

Objective

• To provide a detailed assessment of temperature and precipitation trends in the North Western Mediterranean Basin (NWMB) from 1971 to 2050 by dynamically downscaling global climate scenarios at a high resolution (10 km).

Study Configuration

• Spatial Scale: North Western Mediterranean Basin (NWMB) at 10 km horizontal resolution (76x76 cells), nested within a 30 km domain (100x100 cells) covering parts of Europe and North Africa. 33 vertical sigma layers up to 10 hPa.
• Temporal Scale: 1971–2050 (80 years), with a control period of 1971–2000 and a future period of 2001–2050. Seasonal to yearly assessment.

Methodology and Data

• Models used:
  • Regional Climate Model: Advanced Research Weather Research and Forecasting (WRF-ARW) model version 3.2.1.
  • Global Climate Model (GCM) forcing: ECHAM5/MPIOM (atmosphere–ocean coupled GCM).
  • Reanalysis forcing for control period: ERA40.
  • IPCC-SRES emission scenarios: B1, A1B, and A2.
• Data sources:
  • Observational dataset for validation: Spain02 (SP02) gridded daily surface air temperature and accumulated precipitation at 0.2° resolution.
  • Meteorological stations: Data from 20 high-quality stations from the Meteorological Service of Catalonia (SMC) for local validation.
  • GCM data: ECHAM5/MPIOM simulations (T63L31, approximately 1.875° resolution, 6-hourly).
  • Reanalysis data: ERA40 (2.5° resolution, 6-hourly).

Main Results

• High-resolution (10 km) WRF-ARW simulations significantly improve the spatial distribution of temperature (Pearson's r = 0.98) and precipitation (r = 0.81) climatologies compared to ERA40 reanalysis (r = 0.69 for temperature, r = 0.53 for precipitation) when validated against observations.
• Downscaled results show a slight underestimation of mean temperature (approximately 1.3 K) and an overestimation of the precipitation field (approximately 400 mm/year) compared to observations.
• Temperature Projections (2001-2050 vs. 1971-2000):
  • Annual mean temperature is projected to rise across all scenarios, ranging from 0.4 K to 1.4 K over 50 years.
  • The largest temperature increases are expected during summertime and in high-altitude areas, reaching up to 2.0 K to 2.5 K in the Pyrenees for the A1B and A2 scenarios.
  • Wintertime temperatures are projected to increase by up to 1.6 K in northern areas.
• Precipitation Projections (2001-2050 vs. 1971-2000):
  • Annual mean precipitation is likely to decrease by approximately 5 % to 13 % for the most extreme scenarios.
  • Inter-annual variability of annual mean precipitation is projected to increase.
  • Statistically significant decreases in precipitation are projected for mountain ranges in winter and autumn, with the Pyrenees potentially becoming up to 35 % drier.
  • Summertime precipitation projections show non-statistically significant changes, except for localized reductions of up to 20 % on the north face of the Pyrenees.
  • Inland areas could experience drier springs (up to -30 %), but the signal is weak and not consistently significant across all simulations.

Contributions

• This study provides the first high-resolution (10 km) dynamical downscaling assessment of temperature and precipitation trends for the North Western Mediterranean Basin covering an 80-year period (1971–2050).
• It demonstrates that increasing horizontal resolution significantly improves the representation of spatial patterns for annual mean temperature and precipitation, offering added value for climate analysis in regions with complex topography.
• The research identifies particularly vulnerable areas, such as the Pyrenees, where consistent projections show the highest temperature increases and largest precipitation reductions, providing crucial information for decision-makers regarding freshwater resources.
• It highlights that despite the benefits of high resolution, uncertainties related to seasonal precipitation projections persist, emphasizing the need for continued model and observational data improvements.

Funding

• AEMET and UC for the Spain02 dataset.
• ENSEMBLES project for RCM data.
• ECMWF for the ERA40 reanalysis.
• World Data Center for Climate in Hamburg for the ECHAM5/MPIOM simulations.

Citation

@article{Argüeso2012Highresolution,
  author = {Argüeso, Daniel and Hidalgo‐Muñoz, J. M. and Gámiz‐Fortis, Sonia Raquel and Esteban‐Parra, María Jesús and Castro‐Díez, Yolanda},
  title = {High‐resolution projections of mean and extreme precipitation over Spain using the WRF model (2070–2099 versus 1970–1999)},
  journal = {Journal of Geophysical Research Atmospheres},
  year = {2012},
  doi = {10.1029/2011jd017399},
  url = {https://doi.org/10.1029/2011jd017399}
}