NWT RESEARCH DATABASE

Tags: physical sciences, remote sensing, snow water equivalence, snow

Objective(s): To improve national snow water equivalent (SWE) monitoring capabilities by acquiring the necessary data to develop accurate satellite remotely sensed, passive microwave, estimates in the spatially expansive and persistently snow covered arctic tundra environment; and, to understand and quantify the spatial and temporal contribution of snowmelt water to surface water bodies from the start of spring-melt through to fall freeze-up.

Project Description: The primary objectives of this research are: 1) to improve national snow water equivalent (SWE) monitoring capabilities by acquiring the necessary data to develop accurate satellite remotely sensed, passive microwave, estimates in the spatially expansive and persistently snow covered arctic tundra environment; and, 2) to understand and quantify the spatial and temporal contribution of snowmelt water to surface water bodies from the start of spring-melt through to fall freeze-up. The first objective is to conduct an intensive pre-melt in-situ snow survey for comparison with satellite remote sensing data. The Earth naturally emits long wave radiation in many wavelengths. Some of these wave lengths are not obstructed by the snowpack, but some of the wave lengths are attenuated by the snow. As the snow gets deeper these wave lengths are attenuated to a greater degree. By comparing the non-attenuated to the attenuated microwave wave lengths we can determine how much water there is in the snowpack. In large tundra regions, once this method is developed, the researchers will be able to use satellites to determine, with reasonable confidence, just how much standing water exists in the snowpack. Sampling strategy to meet this objective involves measurements of snow depth and snow density in the 625 km2 field site. As lake ice comprises a significant portion of the tundra landscape the researchers are investigating how lake ice may effect interpretation of satellite data. Samples of ice thickness and character as well as lake bathymetry will be obtained in a variety of different lakes in the vicinity of the Daring Lake camp to determine the variability of lake cover properties. The second objective is to obtain water and snow samples from representative sites throughout the study area to help quantify the contribution of snowmelt water to surface water bodies. In addition, they will be digging snowpits at several sites in the Daring Lake area to sample each individual snow strata for dissolved ionic chemistry. These results will assist in helping them determine (by comparison with snow data collected by Ekati Diamond Mine technicians) how much of the snow sublimated over the winter period either during deposition or while on the ground. The satellite imagery will be analyzed by Environment Canada personnel in Toronto and the chemical analysis will be completed at the lab at Wilfrid Laurier University. This snow survey will take a very small amount of time. The researchers estimate (based on past surveys from 2003-2008) that they will be finished within 8 working days. The fieldwork for this study will be conducted from April 07 to 20, 2009, in the area around the ENR Daring Lake Tundra Ecosystem Research Station (64. 52’ 12” N 111. 35’ 6” W). Research sites will be accessed by snowmobile and are all located with a 50 km radius of the Daring Lake Research Station.