GC042-0012
Detection and description of spatio-temporal patterns in weather-type classifications across Canada
Detection and description of spatio-temporal patterns in weather-type classifications across Canada
Wednesday, 9 December 2020
Poster
Abstract:
As the global climate continues to warm, changes in the characteristics of regional weather challenge the use of binned categorical weather classification systems such as the Spatial Synoptic Classification (SSC).
We examined changes in SSC classes at 110 stations across Canada for the period 1985 to 2015, with results interpolated by Inverse Distance Weighting to a 0.5° by 0.5° geographic grid. Canada is dominated by polar air masses for much of the period, with the majority of Canadian stations exhibiting 50% or more days with polar-type weather in the Winter, Spring, and the Fall. Tropical weather types are atypical, occurring only in the summer (< 25%), spring and fall (< 15%). Moderate weather types are common in the summer across most of the country (< 50%), with a smaller presence in the winter and shoulder months.
Linear regression analysis revealed statistically significant (p < 0.05) decreases in polar weather types for the summer season in the central Canadian Prairies and Eastern Canada, and in the fall across much of Eastern Canada, from Manitoba to the Martimes. Complementary, statistically significant, increases were observed in the proportion of moderate weather types in the same locations. The SSC classification scheme is based solely on surface characteristics without regard to air mass origin; thus, this apparent replacement represents the changing characteristics of seasonal weather, rather than a change in air mass origin, and indicates an overall shift in the climate across much of the Canadian territory.
This research project contributes to advance the understanding of the impacts of the changing global climate on Canada. An understanding of weather has applications for a diverse realm of related topics, from shipping and freight (e.g. lake ice), to agriculture, biological conservation, human health and comfort, tourism, and infrastructure.
This topic remains a subject of active research and the authors anticipate sharing further insights at the AGU fall meeting.
We examined changes in SSC classes at 110 stations across Canada for the period 1985 to 2015, with results interpolated by Inverse Distance Weighting to a 0.5° by 0.5° geographic grid. Canada is dominated by polar air masses for much of the period, with the majority of Canadian stations exhibiting 50% or more days with polar-type weather in the Winter, Spring, and the Fall. Tropical weather types are atypical, occurring only in the summer (< 25%), spring and fall (< 15%). Moderate weather types are common in the summer across most of the country (< 50%), with a smaller presence in the winter and shoulder months.
Linear regression analysis revealed statistically significant (p < 0.05) decreases in polar weather types for the summer season in the central Canadian Prairies and Eastern Canada, and in the fall across much of Eastern Canada, from Manitoba to the Martimes. Complementary, statistically significant, increases were observed in the proportion of moderate weather types in the same locations. The SSC classification scheme is based solely on surface characteristics without regard to air mass origin; thus, this apparent replacement represents the changing characteristics of seasonal weather, rather than a change in air mass origin, and indicates an overall shift in the climate across much of the Canadian territory.
This research project contributes to advance the understanding of the impacts of the changing global climate on Canada. An understanding of weather has applications for a diverse realm of related topics, from shipping and freight (e.g. lake ice), to agriculture, biological conservation, human health and comfort, tourism, and infrastructure.
This topic remains a subject of active research and the authors anticipate sharing further insights at the AGU fall meeting.