Monitoring and Modelling Lake Ice in Canada

点击翻译按钮获取中文摘要

Canada’s lakes are a dominant part of the landscape and experience ice cover in most regions of the country. Lake ice is sensitive to climate variability and changes occurring in lake ice regimes in recent years have been primarily noted through modelling and satellite data since the ground based observation network in Canada essentially ceased to exist by the late 1990s. Satellite imagery can be very useful for monitoring the timing of ice-on/off, however, it currently has limited use for determining ice thickness. Lake ice models present a suitable option for examining ice duration and thickness processes as well as climate influenced changes to the ice cover of lakes. Complicating both modelling and monitoring efforts are the spatial aspects of lakes. Ice cover may not form or decay uniformly across a lake surface, or across lakes in close proximity. This is due to the ice formation and decay being affected by the lake size and shape, as well as the overlying snow cover, which can result in spatially varying ice thickness. The overall objective of this proposal is to investigate the effects of lake size and shape on ice duration and thickness across the temperate, subarctic and High Arctic climate regions and address these effects in the Canadian Lake Ice Model. The chosen lakes are near Haliburton ON, Churchill MB, and Cambridge Bay NU and were selected based on their accessibility and potential for long term monitoring. Automated weather stations will be set up in each region to provide local climate conditions for model input, ice thickness sensors will be installed to monitor ice growth and decay, snow and ice thickness will be measured manually throughout the winter (ON site), and a network of outdoor digital cameras will be installed. Multiple cameras will provide the ability to monitor ice conditions on different sections of the lakes where the shape influences on the snow and ice may differ. Larger lakes will also be monitored using available satellite data. The collected data will be used to improve the effects of snow cover on modelled ice thickness, as well as to develop a technique to address the effect of lake size on the ice-off dates within the lake ice model. This research will contribute new knowledge on spatial patterns of lake ice at a smaller scale than satellites can capture. It will also lead to improvements in the lake ice model with respect to the morphometry of lakes and how climatic regions affect the growth/decay of lake ice. This research is of interest to researchers in hydrology and climatology, as well as biology and limnology with respect to under ice habitat and changing ice conditions on the lake ecosystem. Finally, improving the ability to accurately model ice thickness can contribute to improved predictions in areas such as recreation and transportation (e.g. ice roads), especially in the context of future climate scenarios.