Climate Change Scenarios for the Hudson Bay Region: An Intermodel Comparison

Abstract

General circulation models (GCMs) are unanimous in projecting warmer temperatures in an enhanced CO 2 atmosphere, with amplification of this warming in higher latitudes. The Hudson Bay region, which is located in the Arctic and subarctic regions of Canada, should therefore be strongly influenced by global warming. In this study, we compare the response of Hudson Bay to a transient warming scenario provided by six-coupled atmosphere-ocean models. Our analysis focuses on surface temperature, precipitation, sea-ice coverage, and permafrost distribution. The results show that warming is expected to peak in winter over the ocean, because of a northward retreat of the sea-ice cover. Also, a secondary warming peak is observed in summer over land in the Canadian and Australian-coupled GCMs, which is associated with both a reduction in soil moisture conditions and changes in permafrost distribution. In addition, a relationship is identified between the retreat of the sea-ice cover and an enhancement of precipitation over both land and oceanic surfaces. The response of the sea-ice cover and permafrost layer to global warming varies considerably among models and thus large differences are observed in the projected regional increase in temperature and precipitation. In view of the important feedbacks that a retreat of the sea-ice cover and the distribution of permafrost are likely to play in the doubled and tripled CO 2 climates of Hudson Bay, a good representation of these two parameters is necessary to provide realistic climate change scenarios. The use of higher resolution regional climate model is recommended to develop scenarios of climate change for the Hudson Bay region.

Current state and trends in Canadian Arctic marine ecosystems: II. Heterotrophic food web, pelagic-benthic coupling, and biodiversity

“…In this context, a study to document the occurrence and movements of killer whales (Orcinus orca) in the eastern Arctic was initiated. The decreasing trend in arctic sea ice extent and quality (Gagnon and Gough 2005) is expected to have profound effects on habitat use and movement patterns of bowhead whales, as well as other species including their predators (killer whales). The longer open water season in the eastern Arctic has resulted in an increase in killer whales sightings by northerners during recent years (Higdon and Ferguson 2009).…”

Spatial, Environmental, and Biotic Determinants of Zooplankton Community Composition in Subarctic Lakes and Ponds in Wapusk National Park, Canada

“…This is particularly important given that the HBL houses the southernmost boundary of continuous permafrost in North America, a boundary that is expected to shift northwards with warming. Gagnon and Gough (2005) predicted that, in the short to medium term, permafrost will diminish in this region, thereby thickening the active layer that experiences seasonal thawing and freezing, and possibly increasing nutrient inputs from catchments to lakes (Rautio et al, 2011). Moreover, a longer ice-free season may increase summer evaporation (Smol and Cumming, 2000;Wolfe et al, 2011) and, when combined with reduced overland flow during the spring melt period (Rouse et al, 1997), may reduce hydrological storage in aquatic ecosystems.…”

“…Rühland et al, 2014). Climate models for the HBL project further significant increases in air temperature over the next several decades (Gagnon and Gough, 2005), suggesting that physical changes in these lakes may accelerate and become more pronounced over time. This may lead to increased periods of stratification in all lakes, with strong and sustained thermal stratification likely becoming more important in deeper lakes (e.g.…”

“…Climate change scenarios for the Hudson Bay region suggest that annual air temperatures may increase between 3.9 and 4.5 °C by 2040-2069, under a 2 × CO 2 scenario (Gagnon and Gough, 2005). In light of these projections, and increased pressure from industrial development, high quality baseline data are required to permit effective monitoring of environmental change in aquatic ecosystems within the HBL.…”

Feasibility of Small Wind Turbines in Ontario: Integrating Power Curves with Wind Trends

“…Changing dynamics in lake/sea ice cover and its respective breakup and reformation dates can influence atmospheric conditions and stability. These changes can lead to varying wind speed over the Great Lakes and James Bay region, with a causal link existing between the observed decline in ice cover over the Great Lakes during the past decades, with an increasing wind speed during transition months (winter and fall) [24][25][26][27].…”