Ir. Saunders et Jm. Byrne, ANNUAL AND SEASONAL CLIMATE AND CLIMATIC CHANGES IN THE CANADIAN PRAIRIES SIMULATED BY THE CCC-GCM, Atmosphere-ocean, 32(3), 1994, pp. 621-641
As part of a study on the effects of climatic variability and change o
n the sustainability of agriculture in Alberta, the modelling performa
nce of the second-generation Canadian Climate Centre GCM (general circ
ulation model) is examined. For the region in general, the simulation
of 1 x CO2 mean temperature is generally better than that for mean pre
cipitation, and summer is the season best modelled for each variable.
At the scale of individual grid squares, DJF (December, January, Febru
ary) (temperature) and JJA (June, July, August) (precipitation) are th
e seasons best modelled. The GCM-simulated increases in mean annual te
mperature resulting from a doubling of CO2 are of the order of 5 to 6
degrees C in the Prairie region, with much of this increase resulting
from substantial warming in the winter and spring. Increases in mean a
nnual precipitation are of the order of 50 to 150 mm (changes of +5 to
+15%), with the greatest changes again occurring in winter and spring
. As far as the limited GCM run durations allow, temperature and preci
pitation variance generally show no significant changes from a 1 x CO2
to a 2 X CO2 climate. Increased precipitation in winter and spring do
es not result in greater snow accumulations owing to the magnitude of
warming; and significant decreases in soil moisture content occur in s
ummer and fall. The resulting effects on the growing season and moistu
re regime have the potential to affect agricultural practices in the a
rea.