Evaluation of GCM Simulated Climate over the Canadian Prairie Provinces
2005
Töyrä, Jessika | Pietroniro, Alain | Bonsal, Barrie
The objective of this study was to evaluate eleven Global Climate Model (GCM) simulations based on capabiliy to replicate 1961–1990 mean surface air temperature and total precipitation for the Canadian Prairie Provinces. The seasonal and annual magnitudes and spatial patterns of the GCM climates were compared to those of three observed data sets. The results demonstrated that most of the GCMs simulated the observed mean temperature magnitudes and spatial patterns reasonably well. The spatial correlation coefficients were high (> 0.8) and the pattern root mean square errors (PRMSE) were low (< 2°C) for most models. However, all GCMs over-predicted the total annual precipitation by 8 to 66%. The degree of over-prediction varied seasonally; winter and spring precipitation amounts were highly overestimated, autumn values were moderately over-predicted while summer amounts were only slightly overestimated, or even underestimated in some cases. The GCMs varied considerably in capability to represent precipitation spatial patterns. For example, the spatial correlation coefficients and PRMSEs for annual total precipitation ranged between –0.1 and 0.8 and 35 and 158 mm, respectively. In general, ECHAM4, HadCM3 and NCAR-PCM demonstrated the best simulated mean temperature and total precipitation over the provinces. Seven GCM runs were also used for an intercomparison of modelled future temperature and precipitation scenarios for the 30-year periods centred on 2050 and 2080. The models demonstrated a very high amount of variability in predicted future changes for both mean temperature and total precipitation. These results will contribute to an improved understanding of both present day and future GCM-simulated climate in the Prairie Provinces.
显示更多 [+] 显示较少 [-]