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This paper has examined the relative significance of uncertainty in future climate projections from a subset of the coupled model intercomparison project phase 5 (CMIP5) global climate models for the Prairie Provinces of western Canada. This was undertaken by determining: (a) the contribution of model and scenario uncertainty and natural variability to the total variance of these future projections, and (b) the timing of climate signal emergence from the background noise of natural climate variability. We examined future projections of mean temperature, precipitation and summer climate moisture index (CMI). In this region, natural climate variability plays an important role in future uncertainty until the end of this century, particularly for precipitation and to a lesser extent, summer CMI. Model uncertainty also contributes to total uncertainty for these variables throughout this century, while scenario uncertainty becomes more important towards the end of the century. For the region as a whole, significant climate change (i.e., signal/noise >2) occurs earliest for summer mean temperature, with median time of emergence around 2035 for the RCP8.5 radiative forcing scenario. Although the median precipitation signal emerges from the noise (i.e., signal/noise >1) around the 2070s in winter and the 2080s in spring, significant values do not occur in any season for this variable before 2100. For summer CMI, the median time of emergence for significant change is around 2085. At the grid scale, signal‐to‐noise ratios are significant for all seasons for mean surface air temperature, with earliest times of emergence occurring in summer. In contrast, the summer precipitation signal is not significant this century; for summer CMI, significant values are obtained in the eastern half of the region, occurring from about 2065 onwards. Median times of emergence are towards the end of the century for summer CMI in western Saskatchewan and in Alberta, although some areas of Alberta do not exhibit significant signals this century. [ABSTRACT FROM AUTHOR]

Aim: Wetland loss and degradation threaten biodiversity to an extent greater than most ecosystems. Science‐supported responses require understanding of interacting effects of land use and climate change on wetland biodiversity. Location: Alberta, Canada. Methods: We evaluated how current climate, climate change (as a ghost of the past), land use and wetland water quality relate to aquatic macroinvertebrates and birds. Results: Climatic relationships and climate–land use interactions were observed on chironomid abundance, but not macroinvertebrate taxa richness (MTR) or odonate abundance, which responded to land use and water chemistry. Chironomid abundance was positively associated with cropland and negatively associated with total precipitation. Higher cropland cover and dissolved organic carbon synergistically interacted with total precipitation to affect chironomids. MTR was negatively related to salinity, yet greater area of non‐woody riparian vegetation attenuated salinity effects on MTR. Odonate abundance was negatively related to total phosphorus. Higher grassland cover also increased the negative relationship of total phosphorous to odonate abundance. Climatic relationships and climate–land use interactions were observed on bird species richness (BSR) and abundance of several bird functional groups. Higher BSR and abundances of several bird groups were positively related to average rainfall and greater warming temperatures over time. Area of non‐crop cover and wetlands was positively associated with most bird groups and BSR. Warming temperatures over time ameliorated the negative relationship of higher cropland or less shrubland on aerial insectivores and other bird groups. Main conclusions: Climate patterns and climate change are as important as land use pressures with stronger impacts on birds. Climate change was more influential than current climate and provided novel empirical evidence that progressively warmer, wetter conditions is benefiting some bird groups, including aerial insectivores, a group of conservation concern. Riparian vegetation ameliorated the negative impacts of climate and water quality gradients on MTR and could mitigate global change impacts in agricultural systems. [ABSTRACT FROM AUTHOR]

Research into the potential use of microalgae to produce biofuels is receiving significant attention. In the cold climates of countries like Canada, algae cultivation in open raceway pond (ORP) systems is limited to a short period of the year when pond surface water temperatures and ambient light conditions enable optimal culture growth. In this study we develop techno‐economic assessment models to predict, evaluate, and compare the techno‐economic results from three autotrophic algae cultivation scenarios to produce algae biomass. The first is a modeled ORP site located in the southern USA, which has a minimum biomass selling price (MBSP) for algae of $541 tonne−1 (T−1). The second scenario models an identical ORP system co‐located at a site near Fort Saskatchewan, a northern city in the province of Alberta, Canada. The resulting MBSP is $1288 T−1. A third scenario models a photobioreactor (PBR) cultivation system co‐located at the same northern Alberta site and shows algae production with an MBSP of $550 T−1. Each system is scaled to produce 2000 T day−1 ash‐free dry weight (AFDE) algae biomass. The study concludes that PBR systems deployed at this scale have the potential to reduce production costs significantly ($ T−1) compared to similarly sited ORP systems in Canada, despite climatic factors and high initial capital costs associated with PBR construction. Furthermore, the modeled PBR system required 0.3% of the water required by the ORP cultivation platforms (153 × 103 versus 59 527 × 103 m3) and 0.04% of the land (32 versus. 82 038 ha). © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Ecological analyses often incorporate high‐resolution environmental data to capture species‐environment relationships in modelling applications, and downscaled climate data are increasingly being used for such analyses. While such data products provide high precision, the accuracy of these data is seldom directly tested. Consequently, introduced bias from downscaling algorithms may propagate through analyses that incorporate these data products. Here, we utilize data from the Foothills Climate Array (FCA), a mesoscale grid of 232 weather stations in the prairies and eastern slopes of the Rocky Mountains in southern Alberta, Canada, to evaluate several publicly available downscaled climate products. We consider daily, monthly, and annual records for a suite of temperature and humidity variables. The FCA data are ideal to evaluate climate downscaling because they contain multi‐year observations and cover a range of topographic conditions, from flat prairie grass‐ and croplands to mountainous terrain. We find that the downscaling algorithms improve the accuracy of climate variables over simple interpolations of low‐resolution data, but errors are often large at validation locations (e.g., several °C for temperature variables), and downscaled datasets show notable elevational and seasonal bias for all variables. A bias adjustment analysis demonstrates that such bias can be greatly reduced with relatively simple regression‐based models, even when only a small subset of observational data are used, provided they cover a relatively large spread of elevations. We discuss our findings in the context of climate change and ecological modelling and make general recommendations for consumers of downscaled climate data products. [ABSTRACT FROM AUTHOR]

In June 2013, excessive rainfall associated with an intense weather system triggered severe flooding in southern Alberta, which became the costliest natural disaster in Canadian history. This article provides an overview of the climatological aspects and large-scale hydrometeorological features associated with the flooding event based upon information from a variety of sources, including satellite data, upper air soundings, surface observations and operational model analyses. The results show that multiple factors combined to create this unusually severe event. The event was characterized by a slow-moving upper level low pressure system west of Alberta, blocked by an upper level ridge, while an associated well-organized surface low pressure system kept southern Alberta, especially the eastern slopes of the Rocky Mountains, in continuous precipitation for up to two days. Results from air parcel trajectory analysis show that a significant amount of the moisture originated from the central Great Plains, transported into Alberta by a southeasterly low level jet. The event was first dominated by significant thunderstorm activity, and then evolved into continuous precipitation supported by the synoptic-scale low pressure system. Both the thunderstorm activity and upslope winds associated with the low pressure system produced large rainfall amounts. A comparison with previous similar events occurring in the same region suggests that the synoptic-scale features associated with the 2013 rainfall event were not particularly intense; however, its storm environment was the most convectively unstable. The system also exhibited a relatively high freezing level, which resulted in rain, rather than snow, mainly falling over the still snow-covered mountainous areas. Melting associated with this rain-on-snow scenario likely contributed to downstream flooding. Furthermore, above-normal snowfall in the preceding spring helped to maintain snow in the high-elevation areas, which facilitated the rain-on-snow event. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

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Floods caused by ice-jams on the Peace River are considered to be important for maintaining hydro-ecological conditions of perched basins in the Peace-Athabasca Delta (PAD), Canada, a highly productive and internationally recognized northern boreal ecosystem. Concerns over the potential linkages between regulation of the Peace River in 1968 for hydroelectric production and low Peace River discharge between 1968 and 1971 during the filling of the hydroelectric reservoir, absence of a major ice-jam flood event between 1975 and 1995. and low water levels in perched basins during the 1980s and early 1990s have sparked numerous environmental studies largely aimed at restoring water levels in the PAD. Lack of sufficient long-term hydrological records, however, has limited the ability to objectively assess the importance of anthropogenic factors versus natural climatic forcing in regulating hydroecological conditions of the PAD. Here, we report results of a paleolimnological study on laminated sediments from two oxbow lakes in the PAD, which are located adjacent to major flood distributaries of the Peace River. Sediment core magnetic susceptibility measurements, supported by results from several other physical and geochemical analyses as well as stratigraphic correspondence with recorded high water events on the Peace River, provide proxy records of flood history spanning the past ∼180 and ∼300 years in these two basins. Results indicate that inferred flood frequency has been highly variable over the past 300 years but in decline for many decades beginning as early as the late nineteenth century, well before Peace River regulation. Additionally, several multi-decadal intervals without a major flood have occurred during the past 300 years. While climate-related mechanisms responsible for this variability in flood frequency remain to be determined, as does quantifying the relative roles of river regulation and climate variability on hydro ecological conditions in the PAD since 1968. these results suggest that ecosystem management strategies for the PAD need to explicitly account for natural variations in flood recurrence intervals. [ABSTRACT FROM AUTHOR]