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Canada's climate is warming at a rate about double the global average, leading to potential negative impacts on public infrastructures such as jointed plain concrete pavement (JPCP). In light of this reality of changing climate, the work contained in this paper is aimed at evaluating JPCP's early-age behaviour in response to environmental conditions. HIPERPAV® software and the associated models developed by the U.S. Federal Highway Administration (FHWA) were used to identify cracking potential. A sensitivity analysis was performed to assess the effect of different levels of air temperature, mix temperature, base layer temperature, wind speed, and relative humidity. Additionally, projected extreme temperatures predicted by the Canadian Regional Climate Model (CanRCM) were used to determine the relative impact of climate change on cracking risk. The results demonstrated the increased cracking risk under changing climate in several Canadian cities by mid-century and highlighted the importance of developing a pathway forward for climate adaptation. [ABSTRACT FROM AUTHOR]

Seasonal water temperature data from 388 large Canadian lakes (area ≥ 100 km2) were used to develop improved empirical tools for forecasting the impacts of climate change on the magnitude ( TP) and time of occurrence ( JP) of annual peak surface water temperatures. Analyses of remotely sensed open-water temperatures with sinusoidal models produced estimates of TP and JP predominately better than other models. Those estimates were analyzed for lake and climate patterns. Linear mixed effects regression produced a significant model of TP with fixed positive effects for mean July and annual air temperatures and lake perimeter, but negative effects with mean July and annual percent cloud cover, mean annual precipitation, range of monthly mean global clear sky radiation, area, and elevation. Subsets of the estimates with mean, maximum, or Secchi depth values produced similarly significant models with negative depth coefficients. JP was relatively invariant but small, significant lake and climate effects were detected. The best models identified in our analyses will be useful tools for forecasting how climate change will alter aspects of the limnetic seasonal water temperature cycle that strongly influences the species composition and productivity of their fisheries. [ABSTRACT FROM AUTHOR]

Past trends and future projections of key atmospheric, oceanic, sea ice, and biogeochemical variables were assessed to increase our understanding of climate change impacts on Canadian Arctic marine ecosystems. Four subbasins are evaluated: Beaufort Sea, Canadian Arctic Archipelago, Baffin Bay/Davis Strait, and Hudson Bay Complex. Limited observations, especially for ecosystem variables, compromise the trend analyses. Future projections are predominately from global models with few contributions from available marine basin scale models. The assessment indicates a significant increase in air temperature, slight increases in precipitation and snow depth, and appreciable changes in atmospheric circulation patterns. Projections suggest an increase in storm strength and size, leading to enhanced storm surges and coastal erosion, a slight increase in wave heights, increases in gustiness, and small changes in mean wind speed. An Arctic-wide decrease in the extent of multiyear ice and a spatial and temporal increase in ice-free waters in summer have been observed and are projected to continue into the future. Limited observations of ocean properties show local freshening (Beaufort Sea) and summer warming (Baffin Bay). These trends are projected to continue along with localized strengthening in stratification. Increased ocean acidification has been observed and is projected to continue throughout the Canadian Arctic, leading to severely decreased saturation states of calcium carbonate (aragonite and calcite). Qualitative analysis of biological observations indicate large regional differences. Increased primary production and double bloom development is seen in areas of sea ice retreat where nutrient supply is sufficient, and unchanged or reduced production is seen where nutrients are low or suppressed in response to enhanced stratification. Future primary production projections show inconsistent results, with light-dependent increase or nutrient-limited decrease dominating, dependent on the model. For the next decade, natural intradecadal variability is expected to be of similar importance as longer-term trends. To improve our capacity to assess and project climate change adaptation in marine ecosystems, more consistent observations are needed, especially over marine areas and for biogeochemical variables. Higher resolution basin-scale models are also required to provide locally applicable projections relevant for Arctic communities and management units. [ABSTRACT FROM AUTHOR]