An Investigation of the Thermal and Energy Balance Regimes of Great Slave and Great Bear Lakes

Abstract

Great Slave Lake and Great Bear Lake have large surface areas, water volumes, and high latitudinal positions; are cold and deep; and are subject to short daylight periods in winter and long ones in summer. They are dissimilar hydrologically. Great Slave Lake is part of the Mackenzie Basin flowthrough system. Great Bear Lake is hydrologically isolated in its own relatively small drainage basin and all of its inflow and outflow derive from its immediate watershed. Great Slave Lake's outflow into the Mackenzie River is more than 8 times that from Great Bear Lake. Input from the south via the Slave River provides 82% of this outflow volume. These hydrological differences exert pronounced effects on the thermodynamics, hydrodynamics, and surface climates of each lake. The quantitative results in this study are based on limited datasets from different years that are normalized to allow comparison between the two lakes. They indicate that both lakes have regional annual air temperatures within 2°C of one another, but Great Slave Lake exhibits a much longer open-water period with higher temperatures than Great Bear Lake. During the period when the lakes are warming, each lake exerts a substantial overlake atmospheric cooling, and in the period when the lakes are cooling, each exerts a strong overlake warming. This local cooling and warming cycle is greatest over Great Bear Lake. Temperature and humidity inversions are frequent early in the lake-warming season and very strong lapse gradients occur late in the lake-cooling season. Annually, for both lakes, early ice breakup is matched with late freeze-up. Conversely, late breakup is matched with early freeze-up. The magnitudes of midlake latent heat fluxes (evaporation) and sensible heat fluxes from Great Slave Lake are substantially larger than those from Great Bear Lake during their respective open-water periods. The hypothesis that because they are both large and deep, and are located in high latitudes, Great Slave Lake and Great Bear Lake will exhibit similar surface and near-surface climates that are typical of large lakes in the high latitudes proves invalid because their different hydrological systems impose very different thermodynamic regimes on the two lakes. Additionally, such an extensive north-flowing river system as the Mackenzie is subjected to latitudinally variable meteorological regimes that will differentially influence the hydrology and energy balance of these large lakes. Great Slave Lake is very responsive to climatic variability because of the relation between lake ice and absorbed solar radiation in the high sun season and we expect that Great Bear Lake will be affected in a similar fashion.

Estimating ice phenology on large northern lakes from AMSR-E: algorithm development and application to Great Bear Lake and Great Slave Lake, Canada

“…1), and, respectively, have surface areas of 31.3 × 10 3 km 2 and 28.6 × 10 3 km 2 , and average depths of 76 m and 88 m (Rouse et al, 2008a;Woo et al, 2008). The northern extent of GBL is influenced by colder temperatures than its more southern counterpart (Rouse et al, 2008b). (Table 2).…”

“…GSL is part of the north-flowing river system in the Mackenzie Basin (Rouse et al, 2008b). Situated at a more 238 K.-K. Kang et al: Estimating ice phenology on large northern lakes from AMSR-E southern location, the mean air temperature in the GSL area is generally warmer than that of GBL, and therefore the GSL open-water period is about four to six weeks longer than it is at GBL (Rouse et al, 2008b;Schertzer et al, 2008).…”

Interannual variability in the surface energy budget and evaporation over a large southern inland water in the United States

“…[3] There are a number of long-term eddy covariance measurements and process-based studies for the surface energy budget over inland waters [Blanken et al, 2000;Eaton et al, 2001;Blanken et al, 2003;Rouse et al, 2003;Oswald and Rouse, 2004;Rouse et al, 2005;Vesala et al, 2006;Assouline et al, 2008;Rouse et al, 2008;Tanny et al, 2008;Liu et al, 2009;Blanken et al, 2011;Liu et al, 2011;Nordbo et al, 2011;Liu et al, 2012]. It is noted that, however, most of these measurements were made over highlatitude lakes, such as Great Slave Lake [Blanken et al, 2000;Rouse et al, 2003] and Great Bear Lake [Rouse et al, 2008] in Canada, Lake Valkea-Kotinen in Finland [Vesala et al, 2006;Nordbo et al, 2011], and Lake Superior Spence et al, 2011].…”

“…It is noted that, however, most of these measurements were made over highlatitude lakes, such as Great Slave Lake [Blanken et al, 2000;Rouse et al, 2003] and Great Bear Lake [Rouse et al, 2008] in Canada, Lake Valkea-Kotinen in Finland [Vesala et al, 2006;Nordbo et al, 2011], and Lake Superior Spence et al, 2011]. Liu et al [2012] was the first to report an annual analysis of the surface energy budget over a large southern reservoir.…”

Theoretical study of ice cover phenology at large freshwater lakes based on SMOS MIRAS data

“…As to Baikal and Ladoga, these are Russian language works of Galaziya (1984), Tulokhonov (2008, Rumyantsev et al (2012), Rumyantsev (2015), 15 as well as websites of the Institute of Lake Science of the Russian Academy of Sciences (http://www.limno.org.ru) and the Climatic Reference Book of the Settlements of Russia (http://atlasyakutia.ru/). For GBL and GSL, we used data of Woo et al (2007), Rouse et al (2008), Kang et al (2010Kang et al ( , 2012Kang et al ( , 2014, and Kang (2012), as well as websites of the Canadian Cryospheric Information Network and Polar Data Catalogue (https://www.ccin.ca/home/ccw/lakeice/links), Environment and 20 Natural resources (https://www.canada.ca/en/services/environment.html), Environment and Climate Change Canada (http://www.ec.gc.ca/default.asp?lang=en&n=FD9B0E51-1). In case of Huron, data provided by Rumyantsev et al (2012) and NOAA websites (https://www.glerl.noaa.gov//metdata/, https://coastwatch.glerl.noaa.gov/statistic/statistic.html,) were used.…”