High-resolution Med-CORDEX regional climate model simulations for hydrological impact studies: a first evaluation of the ALADIN-Climate model in Morocco

Abstract. In the framework of the international CORDEX program, new regional climate model (RCM) simulations at high spatial resolutions are becoming available for the Mediterranean region (Med-CORDEX initiative). This study provides the first evaluation for hydrological impact studies of one of these high-resolution simulations in a 1800 km2 catchment located in North Morocco. Different approaches are compared to analyze the climate change impacts on the hydrology of this catchment using a high-resolution RCM (ALADIN-Climate) from the Med-CORDEX initiative at two different spatial resolutions (50 and 12 km) and for two different Radiative Concentration Pathway scenarios (RCP4.5 and RCP8.5). The main issues addressed in the present study are: (i) what is the impact of increased RCM resolution on present-climate hydrological simulations and on future projections? (ii) Are the bias-correction of the RCM model and the parameters of the hydrological model stationary and transferable to different climatic conditions? (iii) What is the climate and hydrological change signal based on the new Radiative Concentration Pathways scenarios (RCP4.5 and RCP8.5)? Results indicate that high resolution simulations at 12 km better reproduce the seasonal patterns, the seasonal distributions and the extreme events of precipitation. The parameters of the hydrological model, calibrated to reproduce runoff at the monthly time step over the 1984–2010 period, do not show a strong variability between dry and wet calibration periods in a differential split-sample test. However the bias correction of precipitation by quantile-matching does not give satisfactory results in validation using the same differential split-sample testing method. Therefore a quantile-perturbation method that does not rely on any stationarity assumption and produces ensembles of perturbed series of precipitation was introduced. The climate change signal under scenarios 4.5 and 8.5 indicates a decrease of respectively −30 to −57% in surface runoff for the mid-term (2041–2062), when for the same period the projections for precipitation are ranging between −15 and −19% and for temperature between +1.3 and +1.9 °C.

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High-resolution Med-CORDEX regional climate model simulations for hydrological impact studies: a first evaluation in Morocco

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-10-5687-2013 ◽

2013 ◽

Vol 10 (5) ◽

pp. 5687-5737 ◽

Cited By ~ 3

Author(s):

Y. Tramblay ◽

D. Ruelland ◽

S. Somot ◽

R. Bouaicha ◽

E. Servat

Keyword(s):

Climate Change ◽

High Resolution ◽

Regional Climate Model ◽

Bias Correction ◽

Hydrological Model ◽

Climate Model ◽

Regional Climate ◽

Impact Studies ◽

Hydrological Impact ◽

Split Sample

Abstract. In the framework of the international CORDEX program, new regional climate model (RCM) simulations at high spatial resolutions are becoming available for the Mediterranean region (Med-CORDEX initiative). This study provides the first evaluation for hydrological impact studies of these high-resolution simulations. Different approaches are compared to analyze the climate change impacts on the hydrology of a catchment located in North Morocco, using a high-resolution RCM (ALADIN-Climate) from the Med-CORDEX initiative at two different spatial resolutions (50 km and 12 km) and for two different Radiative Concentration Pathway scenarios (RCP4.5 and RCP8.5). The main issues addressed in the present study are: (i) what is the impact of increased RCM resolution on present-climate hydrological simulations and on future projections? (ii) Are the bias-correction of the RCM model and the parameters of the hydrological model stationary and transferable to different climatic conditions? (iii) What is the climate and hydrological change signal based on the new Radiative Concentration Pathways scenarios (RCP4.5 and RCP8.5)? Results indicate that high resolution simulations at 12 km better reproduce the seasonal patterns, the seasonal distributions and the extreme events of precipitation. The parameters of the hydrological model, calibrated to reproduce runoff at the monthly time step over the 1984–2010 period, do not show a strong variability between dry and wet calibration periods in a differential split-sample test. However the bias correction of precipitation by quantile-matching does not give satisfactory results in validation using the same differential split-sample testing method. Therefore a quantile-perturbation method that does not rely on any stationarity assumption and produces ensembles of perturbed series of precipitation was introduced. The climate change signal under scenarios 4.5 and 8.5 indicates a decrease of respectively −30% to −57% in surface runoff for the mid-term (2041–2062), when for the same period the projections for precipitation are ranging between −15% and −19% and for temperature between +1.28°C and +1.87°C.

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Is bias correction of Regional Climate Model (RCM) simulations possible for non-stationary conditions?

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-9-12765-2012 ◽

2012 ◽

Vol 9 (11) ◽

pp. 12765-12795 ◽

Cited By ~ 18

Author(s):

C. Teutschbein ◽

J. Seibert

Keyword(s):

Climate Change ◽

Bias Correction ◽

Climate Change Impact ◽

Climate Model ◽

Regional Climate ◽

Climate Conditions ◽

Impact Studies ◽

Split Sample ◽

Sample Test ◽

Change Impact

Abstract. In hydrological climate-change impact studies, Regional Climate Models (RCMs) are commonly used to transfer large-scale Global Climate Model (GCM) data to smaller scales and to provide more detailed regional information. However, there are often considerable biases in RCM simulations, which have led to the development of a number of bias correction approaches to provide more realistic climate simulations for impact studies. Bias correction procedures rely on the assumption that RCM biases do not change over time, because correction algorithms and their parameterizations are derived for current climate conditions and assumed to apply also for future climate conditions. This underlying assumption of bias stationarity is the main concern when using bias correction procedures. It is in principle not possible to test whether this assumption is actually fulfilled for future climate conditions. In this study, however, we demonstrate that it is possible to evaluate how well bias correction methods perform for conditions different from those used for calibration. For five Swedish catchments, several time series of RCM simulated precipitation and temperature were obtained from the ENSEMBLES data base and different commonly-used bias correction methods were applied. We then performed a differential split-sample test by dividing the data series into cold and warm respective dry and wet years. This enabled us to evaluate the performance of different bias correction procedures under systematically varying climate conditions. The differential split-sample test resulted in a large spread and a clear bias for some of the correction methods during validation years. More advanced correction methods such as distribution mapping performed relatively well even in the validation period, whereas simpler approaches resulted in the largest deviations and least reliable corrections for changed conditions. Therefore, we question the use of simple bias correction methods such as the widely used delta-change approach and linear scaling for RCM-based climate-change impact studies and recommend using higher-skill bias correction methods.

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Bias correction of regional climate model simulations for hydrological climate-change impact studies: Review and evaluation of different methods

Journal of Hydrology ◽

10.1016/j.jhydrol.2012.05.052 ◽

2012 ◽

Vol 456-457 ◽

pp. 12-29 ◽

Cited By ~ 694

Author(s):

Claudia Teutschbein ◽

Jan Seibert

Keyword(s):

Climate Change ◽

Regional Climate Model ◽

Bias Correction ◽

Climate Change Impact ◽

Climate Model ◽

Regional Climate ◽

Model Simulations ◽

Impact Studies ◽

Change Impact ◽

Climate Model Simulations

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Projected climate change over Kuwait simulated using a WRF high resolution regional climate model

10.5194/egusphere-egu2020-1867 ◽

2020 ◽

Author(s):

Hussain Alsarraf

Keyword(s):

Climate Change ◽

High Resolution ◽

Regional Climate Model ◽

Arabian Peninsula ◽

Climate Model ◽

Regional Climate ◽

Dynamic Downscaling ◽

Model Simulations ◽

Average Maximum ◽

The Impact

The purpose of this study is to examine the impact of climate change on the changes on summer surface temperatures between present (2000-2010) and future (2050-2060) over the Arabian Peninsula and Kuwait. In this study, the influence of climate change in the Arabian Peninsula and especially in Kuwait was investigated by high resolution (36, 12, and 4 km grid spacing) dynamic downscaling from the Community Climate System Model CCSM4 using the WRF Weather Research and Forecasting model. The downscaling results were first validated by comparing National Centers for Environmental Prediction NCEP model outputs with the observational data. The global climate change dynamic downscaling model was run using WRF regional climate model simulations (2000-2010) and future projections (2050-2060). The influence of climate change in the Arabian Peninsula can be projected from the differences between the two period&#8217;s model simulations. The regional model simulations of the average maximum surface temperature in summertime predicted an increase from 1&#9702;C to 3 &#9702;C over the summertime in Kuwait by midcentury.&#160;

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