The Mackenzie GEWEX Study(MAGS) is a major Canadian contribution to the Global Energy and Water cycle Experiment (GEWEX). The Mackenzie River is the largest North American source of fresh water for the Arctic Ocean. One of the objectives of MAGS is to quantify the hydrologic cycle and energy fluxes of the Mackenzie Basin.
Because the observation network is very sparse over the Mackenzie River Basin, the output from high-resolution analysis and forecast models, Global Environmental Multi-scale(GEM) model , is used in the current study. We are trying to assess the reliability of the budget estimates, to identify deficiencies in the observations and model analyses, and to validate the budget estimates against observed river runoffs.
The atmospheric moisture budget over the Mackenzie River Basin is computed over the whole and sub-basin scales. For the 2 years studied, we find that the Mackenzie basin is a net moisture sink, that is, more moisture is advected into the basin from the west than leaves in the east. There are strong seasonal variations in the flux convergence, with its minimum in the summer. The small magnitude of the moisture flux convergence indicates that most of the water vapor is transported horizontally "through" the basin in the atmosphere, and only a small portion falls to the ground.