Atmospheric and Climate Science Directorate

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Water Resources in a Northern Environment

The MacKenzie GEWEX Study

Canada's freshwater resources are among the largest in the world. The Mackenzie River is the largest North American source of freshwater entering the Arctic Ocean and this has an important influence on the global ocean circulation and long-term climate. The Mackenzie Basin extends from the mountainous Cordillera to the Canadian Shield and from grasslands to tundra. A strong warming trend has been observed for this area and this changing climate can alter the nature of the water resources in the region. Since northern rivers and lakes are major transportation arteries, changes in water levels could also have dramatic impacts on the socio-economic activities in the basin.

A portable meteorological tower at the Inuvik, NT. upper air site.

When the World Meteorological Organization's World Climate Research Program initiated the Global Energy and Water Cycle Experiment (GEWEX) in 1988, Canada's contribution was to study a northern watershed in order to expand knowledge of cold climate regions. The Canadian research community of over thirty government and university research groups coalesced to measure and model the atmospheric and hydrologic cycles of the Mackenzie Basin. This collaborative effort, called the Mackenzie GEWEX Study, or (MAGS), is documenting the energy and water cycles of the basin for the first time.

MAGS is a long-term (1996-2005), multi-phased study, focused on understanding and modelling the impacts that climate variability and climate change could have on the meteorology and hydrology of the area. The project has already produced many new and exciting findings since its inception. For example, scientists found that up to half of the summer precipitation that falls over the basin comes from land surface evaporation within the basin. This means that the hydrologic cycle is very sensitive to changes in characteristics of the land surface. This discovery is particularly important since we know that land surfaces are likely to change and permafrost is likely to melt as a result of global warming.

MAGS research has also significantly improved our knowledge of important but poorly understood northern climate processes. These include the quantification of water and energy fluxes from surface snow and northern lakes, the discovery of new runoff processes in frozen soils and bedrocks, and the elucidation of some cold-region cloud and precipitation processes. This new knowledge, along with the field data collected in MAGS, is currently used by scientists from the Meteorological Service of Canada MSC and international weather centres to improve climate and weather prediction models. The improved models will be essential in assessing the impacts of climate change for a northern country like Canada.

MAGS will be a key contributor to climate impacts knowledge for many years to come. The research methods and tools developed by MAGS are now being applied to other watersheds in Canada and other northern countries.

“MAGS has made significant contributions to GEWEX.The project has provided better representations of land surface and snow cover impacts that are improving climate, water and energy cycle predictions at high latitudes.” Paul D.Try
Director International
GEWEX Project Office

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