Inclement climate conditions have made the Arctic Ocean logistically difficult to study, and thus, our historical knowledge of Arctic Ocean processes are limited. Recent observations indicate rapid and abrupt changes in climate. These changes are thought to includes rising temperatures, increase storm activity, altered freshwater balance and a notable decrease in the concentration and extent of sea ice covering the Arctic Ocean. Increasing awareness of these changing conditions and our poor knowledge of how the physical environment influences carbon fluxes, planktonic productivity and biogeochemical cycling have lead to international efforts to address these questions. The data presented here addresses biogeochemical cycling and phytoplankton primary production in the pelagic ecosystem. Given the pace of environmental change in the arctic (rapid ice retreat, record minimum ice extents, and temperature rise) and the relatively little historical data that is available for the region, the data presented here can also be used as a baseline data set from which predictions can be made and future observations can be compared. / Conducted as part of the Canadian Arctic Shelf Exchange Study (CASES), this thesis provides a current review of nutrient dynamics and cycling, and estimates of annual new and net primary production for the Mackenzie Shelf, the Amundsen Gulf and the Cape Bathurst polynya in the southeastern Beaufort Sea in the Canadian Arctic Ocean.

No description available.

Both the SW South China Sea and southern Beaufort Sea represent areas of extended continental crust, located on continental margins associated with oceanic spreading centres and zones of continent ocean transition (COT). Multichannel seismic reflection data are interpreted to characterize the COT in the SW South China Sea and the Southern Beaufort Sea. Based on the modelling and subsidence analysis, these two areas, SW South China Sea and southern Beaufort Sea, are compared with each other and the process of formation of hyper-extended crust in marginal oceanic basins can be conceptually modelled. It is noted that the initial weak thinning of the continental crust happened and the ductile middle/lower crust is coupled with the brittle upper crust. As extension continued, the continental crust is thinned down to ~10km, which is in accord with depth-dependent lithosphere thinning. Major crustal thinning is unlikely to result from brittle, high-angle normal fault in the upper crust. The degrees of lower crustal extension are so high and very high amounts of lower crustal extension, presumably achieved by ductile flow, would be required to have affected the crust within the COT. The seafloor spreading centre existed in the area adjacent to the research regions, so the extension within the COT occurred prior to the onset of seafloor spreading and the lower ductile flow is away from the continent and towards the oceanic crust. The interpretations require that the continental lithosphere prior to seafloor spreading must have been very weak given the evidence for significant lower crustal flow, inferred shallow depth of the brittle ductile transition and the fact that the COT continued to extend after the cessation of seafloor spreading.

A detailed examination of low visibility (LV) occurrences and the weather types that cause low visibility, with a focus on fog, was performed for five weather stations in the western Canadian Arctic, in the vicinity of the Amundsen Gulf area of the eastern Beaufort Sea. A series of climatologies were developed that established patterns of LV occurrence as a proportion of all observations and as a function of LV events caused by fog. Frequency climatologies for other weather types were also performed; in particular, for snow, blowing snow, rain, and drizzle. Annual climatologies were used to identify trends in several weather parameters over the 1980-2015 period of study. Monthlies were used to identify typical patterns of occurrence over the course of a year, and hourlies over the course of a day. A dataset of multi-hour fog events was also created; some of these were related to synoptic patterns. Analysis was also broken down by season. Results indicate several things. Monthly climatologies showed considerable diversity across the study area. Three distinct groupings were noted: Tuktoyaktuk and Ulukhaktok with a maximum frequency of LV conditions in February, Aklavik and Inuvik with a maxiumum frequency in October, and Sachs Harbour in August. The February maximum in Tuktoyaktuk and Ulukhaktok was related to cold air temperatures combined with small amounts of moisture from sea ice leads. The Alkavik and Inuvik October maximum was related to moisture advected over land from remaining open water, as well as diurnal snow melt adding moisture to the boundary layer that condenses as the evening cools off. The August maximum in Sachs Harbour is a reflection of proximity to open water and cold air temperatures. Hourly climatologies in the spring/fall season showed most stations have maximum occurrence of LV events caused by fog in the early morning. This is a radiative effect; cooling overnight causes radiation fog that peaks in occurrence just as morning begins. This peak is pushed into the midday in the winter, and is much weaker in the summer, both reflections of the changing pattern of daylight hours. / Graduate

The seasonal pattern of ice motion in response to wind forcing and potential consequences to upwelling on the Mackenzie Shelf are considered using satellite-derived ice motion data from the National Snow and Ice Data Center and the NCEP 10 m wind data. The frequency of strong upwelling-favorable alongshore ice motion is high in early winter (November and December) compared to middle and late winter (January to May).For periods when the alongshore component of the wind is upwelling-favorable, the ratio of ice drift divided by wind speed on the Mackenzie Shelf is 0.024 in November and0.008 in March; we conjecture that this ratio decreases as winter progresses because the internal ice stress becomes stronger as both ice thickness and ice concentration increase. This constitutes a possible 10-fold decrease in the seasonal transmission of wind stress to the underlying water from November to March. This ratio in May (0.015) is higher than that in March. We suggest that it is because the internal ice stress becomes weaker as ice concentration decreases on the Mackenzie Shelf in May. Hence, under the same wind forcing, the potential for winter upwelling on Mackenzie Shelf may be enhanced if climate warming results in reduced ice thickness and/or ice concentration. Numerical model results show that the stress on the shelf could be reduced because of the internal ice stress from the pack ice over the deep ocean when the ice moves like a rigid body. We found that the model results are not realistic when the ice strength is 5,000 Nm-2. When the ice strength is 27,500 Nm-2, the model results are more realistic.

The seasonal pattern of ice motion in response to wind forcing and potential consequences to upwelling on the Mackenzie Shelf are considered using satellite-derived ice motion data from the National Snow and Ice Data Center and the NCEP 10 m wind data. The frequency of strong upwelling-favorable alongshore ice motion is high in early winter (November and December) compared to middle and late winter (January to May).For periods when the alongshore component of the wind is upwelling-favorable, the ratio of ice drift divided by wind speed on the Mackenzie Shelf is 0.024 in November and0.008 in March; we conjecture that this ratio decreases as winter progresses because the internal ice stress becomes stronger as both ice thickness and ice concentration increase. This constitutes a possible 10-fold decrease in the seasonal transmission of wind stress to the underlying water from November to March. This ratio in May (0.015) is higher than that in March. We suggest that it is because the internal ice stress becomes weaker as ice concentration decreases on the Mackenzie Shelf in May. Hence, under the same wind forcing, the potential for winter upwelling on Mackenzie Shelf may be enhanced if climate warming results in reduced ice thickness and/or ice concentration. Numerical model results show that the stress on the shelf could be reduced because of the internal ice stress from the pack ice over the deep ocean when the ice moves like a rigid body. We found that the model results are not realistic when the ice strength is 5,000 Nm-2. When the ice strength is 27,500 Nm-2, the model results are more realistic.

The seasonal pattern of ice motion in response to wind forcing and potential consequences to upwelling on the Mackenzie Shelf are considered using satellite-derived ice motion data from the National Snow and Ice Data Center and the NCEP 10 m wind data. The frequency of strong upwelling-favorable alongshore ice motion is high in early winter (November and December) compared to middle and late winter (January to May).For periods when the alongshore component of the wind is upwelling-favorable, the ratio of ice drift divided by wind speed on the Mackenzie Shelf is 0.024 in November and0.008 in March; we conjecture that this ratio decreases as winter progresses because the internal ice stress becomes stronger as both ice thickness and ice concentration increase. This constitutes a possible 10-fold decrease in the seasonal transmission of wind stress to the underlying water from November to March. This ratio in May (0.015) is higher than that in March. We suggest that it is because the internal ice stress becomes weaker as ice concentration decreases on the Mackenzie Shelf in May. Hence, under the same wind forcing, the potential for winter upwelling on Mackenzie Shelf may be enhanced if climate warming results in reduced ice thickness and/or ice concentration. Numerical model results show that the stress on the shelf could be reduced because of the internal ice stress from the pack ice over the deep ocean when the ice moves like a rigid body. We found that the model results are not realistic when the ice strength is 5,000 Nm-2. When the ice strength is 27,500 Nm-2, the model results are more realistic. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

<p> Cost data from different marine and pipeline scenarios were analyzed under changing world oil price and discount assumptions to determine a minimum economic scale for Beaufort Sea - Mackenzie Delta hydrocarbon development. Environmental and socio-economic impacts were included to supplement the purely economic analysis. </p> <p> The minimum economic scale project, a sixteen-inch pipeline through the Mackenzie Valley, was found to be marginally economic. When environmental and social costs were assumed to be internalized by the companies involved, and federal government exploration and development incentives disregarded, the minimum scale project was found to yield a negative internal rate of return. </p> / Thesis / Bachelor of Arts (BA)

No description available.

High latitude areas have been identified in most GCMs as regions where global warming will appear earliest and be the greatest. Since much of Canada's north is underlain by permafrost, a warming of 3-5°C could cause widespread erosion and thermokarst. The Arctic coastal zone is particularly vulnerable, as it lies at the interface between terrestrial systems dominated by permafrost, and marine systems dominated by sea ice and wave action. This study aims at understanding some mechanisms of arctic coastal erosion, such as thermoerosional niches and block failure. The final goal of this research is to identify the areas of Herschel Island, Yukon Territory, which are likely to experience the greatest magnitude of change in the near future. This information is then coupled with a climate change scenario in order to predict future coastal erosion in the area.