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The Canadian Sea Ice and Snow Evolution (Can- SISE) Network is a climate research network focused on developing and applying state of the art observational data to advance dynamical prediction, projections, and understanding of seasonal snow cover and sea ice in Canada and the circumpolar Arctic. Here, we present an assessment from the CanSISE Network on trends in the historical record of snow cover (fraction, water equivalent) and sea ice (area, concentration, type, and thickness) across Canada. We also assess projected changes in snow cover and sea ice likely to occur by mid-century, as simulated by the Coupled Model Intercomparison Project Phase 5 (CMIP5) suite of Earth system models. The historical datasets show that the fraction of Canadian land and marine areas covered by snow and ice is decreasing over time, with seasonal and regional variability in the trends consistent with regional differences in surface temperature trends. In particular, summer sea ice cover has decreased significantly across nearly all Canadian marine regions, and the rate of multi-year ice loss in the Beaufort Sea and Canadian Arctic Archipelago has nearly doubled over the last 8 years. The multi-model consensus over the 2020-2050 period shows reductions in fall and spring snow cover fraction and sea ice concentration of 5-10% per decade (or 15-30% in total), with similar reductions in winter sea ice concentration in both Hudson Bay and eastern Canadian waters. Peak pre-melt terrestrial snow water equivalent reductions of up to 10% per decade (30% in total) are projected across southern Canada. [ABSTRACT FROM AUTHOR]

The Canadian Sea Ice and Snow Evolution (Can- SISE) Network is a climate research network focused on developing and applying state-of-the-art observational data to advance dynamical prediction, projections, and understanding of seasonal snow cover and sea ice in Canada and the circumpolar Arctic. This study presents an assessment from the CanSISE Network of the ability of the second-generation Canadian Earth System Model (CanESM2) and the Canadian Seasonal to Interannual Prediction System (CanSIPS) to simulate and predict snow and sea ice from seasonal to multi-decadal timescales, with a focus on the Canadian sector. To account for observational uncertainty, model structural uncertainty, and internal climate variability, the analysis uses multi-source observations, multiple Earth system models (ESMs) in Phase 5 of the Coupled Model Intercomparison Project (CMIP5), and large initial-condition ensembles of CanESM2 and other models. It is found that the ability of the CanESM2 simulation to capture snow-related climate parameters, such as cold-region surface temperature and precipitation, lies within the range of currently available international models. Accounting for the considerable disagreement among satellite-era observational datasets on the distribution of snow water equivalent, CanESM2 has too much springtime snow mass over Canada, reflecting a broader northern hemispheric positive bias. Biases in seasonal snow cover extent are generally less pronounced. CanESM2 also exhibits retreat of springtime snow generally greater than observational estimates, after accounting for observational uncertainty and internal variability. Sea ice is biased low in the Canadian Arctic, which makes it difficult to assess the realism of long-term sea ice trends there. The strengths and weaknesses of the modelling system need to be understood as a practical tradeoff: the Canadian models are relatively inexpensive computationally because of their moderate resolution, thus enabling their use in operational seasonal prediction and for generating large ensembles of multidecadal simulations. Improvements in climate-prediction systems like CanSIPS rely not just on simulation quality but also on using novel observational constraints and the ready transfer of research to an operational setting. Improvements in seasonal forecasting practice arising from recent research include accurate initialization of snow and frozen soil, accounting for observational uncertainty in forecast verification, and sea ice thickness initialization using statistical predictors available in real time. [ABSTRACT FROM AUTHOR]

We present an algorithm to detect melt onset over Arctic sea ice using high resolution synthetic aperture radar (SAR) images from RADARSAT. The algorithm is based on the temporal evolution of the SAR backscatter coefficient (σ°), using an ice type specific threshold approach that also corrects for incidence angle variation. Using 4457 RADARSAT images, the algorithm was applied over sea ice in the northern Canadian Arctic Archipelago that low spatial resolution microwave sensors have difficulty resolving, thus generating a new time series of melt onset from 1997 to 2014. Over the 1997–2014 period, the mean annual average melt onset date in the northern CAA was on year day 164 (mid–June) with a standard deviation of 4 days. No significant trend for melt onset date was found over the 18-year period. An earlier (later) melt onset was associated with increased (decreased) solar energy absorption ( r = 0.64, significant at 95% confidence) and subsequently associated in lighter (heavier) September sea ice coverage in the northern CAA ( r = 0.62, significant at 95% confidence). RADARSAT estimates of melt onset were found to be in good agreement but more robust compared to passive microwave and scatterometer estimates over the northern CAA. [ABSTRACT FROM AUTHOR]

This article examines the interactions between sea ice change and patterns of cruise ship tourism through the Northwest Passage of Arctic Canada and how local communities are responding to this change. During the period 2006–2010, the Passage has emerged as the most popular expedition cruise area in the Canadian Arctic with an increase in planned cruises by 70%. This dramatic increase in cruise traffic has been, in part, facilitated by improved access as a result of decreases in sea ice. Since 1968, total sea ice area in northern route of the Northwest Passage has decreased by 11% per decade and total sea ice area in the southern of the Northwest Passage has decreased by 16% per decade. Integrating research from both social and geophysical science, this article presents an analysis of changing cruise tourism patterns through the Northwest Passage and analyses resident responses from Passage communities including Ulukhaktok, Gjoa Haven, and Pond Inlet. Discussion is focused on issues associated with infrastructure, security, protection of the marine environment, human safety, and search and rescue. This research is important to help prepare communities, policy makers, as well as the cruise sector itself, to be responsive to change in these remote locations. [ABSTRACT FROM AUTHOR]

During the International Polar Year (IPY), comprehensive observational research programs were undertaken to increase our understanding of the Canadian polar cryosphere response to a changing climate. Cryospheric components considered were snow, permafrost, sea ice, freshwater ice, glaciers and ice shelves. Enhancement of conventional observing systems and retrieval algorithms for satellite measurements facilitated development of a snapshot of current cryospheric conditions, providing a baseline against which future change can be assessed. Key findings include: 1. surface air temperatures across the Canadian Arctic exhibit a warming trend in all seasons over the past 40 years. A consistent pan-cryospheric response to these warming temperatures is evident through the analysis of multi-decadal datasets; 2. in recent years (including the IPY period) a higher rate of change was observed compared to previous decades including warming permafrost, reduction in snow cover extent and duration, reduction in summer sea ice extent, increased mass loss from glaciers, and thinning and break-up of the remaining Canadian ice shelves. These changes illustrate both a reduction in the spatial extent and mass of the cryosphere and an increase in the temporal persistence of melt related parameters. The observed changes in the cryosphere have important implications for human activity including the close ties of northerners to the land, access to northern regions for natural resource development, and the integrity of northern infrastructure. [ABSTRACT FROM AUTHOR]

Although cruise travel to the Canadian Arctic has grown steadily since 1984, some commentators have suggested that growth in this sector of the tourism industry might accelerate, given the warming effects of climate change that are making formerly remote Canadian Arctic communities more accessible to cruise vessels. Using sea-ice charts from the Canadian Ice Service, we argue that Global Climate Model predictions of an ice-free Arctic as early as 2050-70 may lead to a false sense of optimism regarding the potential exploitation of all Canadian Arctic waters for tourism purposes. This is because climate warming is altering the character and distribution of sea ice, increasing the likelihood of hullpenetrating, high-latitude, multi-year ice that could cause major pitfalls for future navigation in some places in Arctic Canada. These changes may have negative implications for cruise tourism in the Canadian Arctic, and, in particular, for tourist transits through the Northwest Passage and High Arctic regions. [ABSTRACT FROM AUTHOR]

Ridges in sea ice and the convergent forces that form them are a serious hazard to ships traveling in the Arctic, but few studies have examined ridge distribution at a basin level in the Canadian Arctic. The Hudson Strait, which connects Hudson Bay and the North Atlantic, is a site of ongoing winter shipping where vessels frequently encounter pressured ice conditions and ridging. Here, RADARSAT-1 and RADARSAT-2 ScanSAR Wide images were used to identify ridges manually in a winter shipping corridor in the Hudson Strait for the period 1997 to 2012. Ridge count peaked in the month of March. No significant linear trend in the number of ridges was identified on either a monthly or annual scale, which is the result of great variability from year to year. However, spatial patterns of ridging distribution were evident: ridging occurred primarily in the eastern and western sectors of the study area, both in the region between Charles Island and the Quebec coastline and at the eastern entrance to the Hudson Strait. Seasonal sea level pressure (SLP) patterns from years of high and low ridge density were compared, but consistent correlations between SLP and ridge density were not found. The impacts of one-time storm events on ridge densities were also investigated. More analysis is needed to understand the factors influencing ridge density in the Hudson Strait. [ABSTRACT FROM AUTHOR]

Tourism in the Hudson Bay region of central northern Canada generally is associated with non-consumptive forms of nature-based activities (such as polar bear viewing). However, the region has experienced variable growth in the cruise sector in recent years. This paper examines patterns of cruise activity in all subregions of the Hudson Bay region during three cruise seasons (2006, 2008, and 2009) and mainly reveals a pattern of decline. Since the prevalence of sea ice is an important part of visitor experiences of polar cruises, we examine sea ice change and occurrence of icebergs in the Hudson Bay region. Our sea ice analysis suggests that the length of the navigable shipping season is increasing in this region, which may facilitate both earlier and later shipping. But in terms of cruise traffic, we suggest that the demise of ice coverage signals a possible decline in cruise activity in most of the Hudson Bay region because ice-supported wildlife may shift north with the diminishing ice regime. Given the possible environmental and socio-cultural implications of changing cruise activity patterns in the Arctic and the absence of broad-scale monitoring and surveillance of the industry, use of these available data sources is vital to building a clearer picture. [ABSTRACT FROM AUTHOR]