Means and Extremes: Evaluation of a CMIP6 Multi-Model Ensemble in Reproducing Historical Climate Characteristics across Alberta, Canada
This study evaluates General Circulation Models (GCMs) participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6) for their ability in simulating historical means and extremes of daily precipitation (P), and daily maximum (Tmax), and minimum temperature (Tmin). Models are evaluated a...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-03-01
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| Series: | Water |
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| Online Access: | https://www.mdpi.com/2073-4441/13/5/737 |
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| author | Badrul Masud Quan Cui Mohamed E. Ammar Barrie R. Bonsal Zahidul Islam Monireh Faramarzi |
| author_facet | Badrul Masud Quan Cui Mohamed E. Ammar Barrie R. Bonsal Zahidul Islam Monireh Faramarzi |
| author_sort | Badrul Masud |
| collection | DOAJ |
| description | This study evaluates General Circulation Models (GCMs) participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6) for their ability in simulating historical means and extremes of daily precipitation (P), and daily maximum (Tmax), and minimum temperature (Tmin). Models are evaluated against hybrid observations at 2255 sub-basins across Alberta, Canada using established statistical metrics for the 1983–2014 period. Three extreme indices including consecutive wet days (CWD), summer days (SD), and warm nights (WN) are defined based on the peak over the threshold approach and characterized by duration and frequency. The tail behaviour of extremes is evaluated using the Generalized Pareto Distribution. Regional evaluations are also conducted for four climate sub-regions across the study area. For both mean annual precipitation and mean annual daily temperature, most GCMs more accurately reproduce the observations in northern Alberta and follow a gradient toward the south having the poorest representation in the western mountainous area. Model simulations show statistically better performance in reproducing mean annual daily Tmax than Tmin, and in reproducing annual mean duration compared to the frequency of extreme indices across the province. The Kernel density curves of duration and frequency as simulated by GCMs show closer agreement to that of observations in the case of CWD. However, it is slightly (completely) overestimated (underestimated) by GCMs for warm nights (summer days). The tail behaviour of extremes indicates that GCMs may not incorporate some local processes such as the convective parameterization scheme in the simulation of daily precipitation. Model performances in each of the four sub-regions are quite similar to their performances at the provincial scale. Bias-corrected and downscaled GCM simulations using a hybrid approach show that the downscaled GCM simulations better represent the means and extremes of P characteristics compared to Tmax and Tmin. There is no clear indication of an improved tail behaviour of GPD based on downscaled simulations. |
| first_indexed | 2024-03-10T13:25:06Z |
| format | Article |
| id | doaj.art-6712984788774cd7b22f4c34ea2abd56 |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-03-10T13:25:06Z |
| publishDate | 2021-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-6712984788774cd7b22f4c34ea2abd562023-11-21T09:42:50ZengMDPI AGWater2073-44412021-03-0113573710.3390/w13050737Means and Extremes: Evaluation of a CMIP6 Multi-Model Ensemble in Reproducing Historical Climate Characteristics across Alberta, CanadaBadrul Masud0Quan Cui1Mohamed E. Ammar2Barrie R. Bonsal3Zahidul Islam4Monireh Faramarzi5Watershed Science and Modelling Laboratory, Department of Earth and Atmospheric Sciences, University of Alberta, 1-26, Earth Sciences Building, Edmonton, AB T6G 2E3, CanadaWatershed Science and Modelling Laboratory, Department of Earth and Atmospheric Sciences, University of Alberta, 1-26, Earth Sciences Building, Edmonton, AB T6G 2E3, CanadaWatershed Science and Modelling Laboratory, Department of Earth and Atmospheric Sciences, University of Alberta, 1-26, Earth Sciences Building, Edmonton, AB T6G 2E3, CanadaEnvironment and Climate Change Canada, 11 Innovation Boulevard, Saskatoon, SK S7N 3H5, CanadaWater and Waste Policy Branch, Alberta Environment and Parks, Edmonton, AB T5K 2J6, CanadaWatershed Science and Modelling Laboratory, Department of Earth and Atmospheric Sciences, University of Alberta, 1-26, Earth Sciences Building, Edmonton, AB T6G 2E3, CanadaThis study evaluates General Circulation Models (GCMs) participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6) for their ability in simulating historical means and extremes of daily precipitation (P), and daily maximum (Tmax), and minimum temperature (Tmin). Models are evaluated against hybrid observations at 2255 sub-basins across Alberta, Canada using established statistical metrics for the 1983–2014 period. Three extreme indices including consecutive wet days (CWD), summer days (SD), and warm nights (WN) are defined based on the peak over the threshold approach and characterized by duration and frequency. The tail behaviour of extremes is evaluated using the Generalized Pareto Distribution. Regional evaluations are also conducted for four climate sub-regions across the study area. For both mean annual precipitation and mean annual daily temperature, most GCMs more accurately reproduce the observations in northern Alberta and follow a gradient toward the south having the poorest representation in the western mountainous area. Model simulations show statistically better performance in reproducing mean annual daily Tmax than Tmin, and in reproducing annual mean duration compared to the frequency of extreme indices across the province. The Kernel density curves of duration and frequency as simulated by GCMs show closer agreement to that of observations in the case of CWD. However, it is slightly (completely) overestimated (underestimated) by GCMs for warm nights (summer days). The tail behaviour of extremes indicates that GCMs may not incorporate some local processes such as the convective parameterization scheme in the simulation of daily precipitation. Model performances in each of the four sub-regions are quite similar to their performances at the provincial scale. Bias-corrected and downscaled GCM simulations using a hybrid approach show that the downscaled GCM simulations better represent the means and extremes of P characteristics compared to Tmax and Tmin. There is no clear indication of an improved tail behaviour of GPD based on downscaled simulations.https://www.mdpi.com/2073-4441/13/5/737climate extremeshybrid downscalingtail behaviourpeaks over thresholdCMIP6 |
| spellingShingle | Badrul Masud Quan Cui Mohamed E. Ammar Barrie R. Bonsal Zahidul Islam Monireh Faramarzi Means and Extremes: Evaluation of a CMIP6 Multi-Model Ensemble in Reproducing Historical Climate Characteristics across Alberta, Canada Water climate extremes hybrid downscaling tail behaviour peaks over threshold CMIP6 |
| title | Means and Extremes: Evaluation of a CMIP6 Multi-Model Ensemble in Reproducing Historical Climate Characteristics across Alberta, Canada |
| title_full | Means and Extremes: Evaluation of a CMIP6 Multi-Model Ensemble in Reproducing Historical Climate Characteristics across Alberta, Canada |
| title_fullStr | Means and Extremes: Evaluation of a CMIP6 Multi-Model Ensemble in Reproducing Historical Climate Characteristics across Alberta, Canada |
| title_full_unstemmed | Means and Extremes: Evaluation of a CMIP6 Multi-Model Ensemble in Reproducing Historical Climate Characteristics across Alberta, Canada |
| title_short | Means and Extremes: Evaluation of a CMIP6 Multi-Model Ensemble in Reproducing Historical Climate Characteristics across Alberta, Canada |
| title_sort | means and extremes evaluation of a cmip6 multi model ensemble in reproducing historical climate characteristics across alberta canada |
| topic | climate extremes hybrid downscaling tail behaviour peaks over threshold CMIP6 |
| url | https://www.mdpi.com/2073-4441/13/5/737 |
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