Deep ventilation of Lake Baikal waters due to spring thermal bars

Abstract

Increase of density due to mixing (cabbeling instability) in a spring thermal bar in Lake Baikal results in the sinking of cold surface water (T = 3.2−3.4°C, w = 0.3 cm s−1) below the profile of Tmd. This density increase generates forced convection and subsequent movement of cold water along the underwater slope to maximum depths. Cooling of deep and near‐bottom waters caused by forced convection is compensated during other seasons of the year by eddy heat flux directed toward the bottom. On a long‐term basis, vertical temperature profiles in deep waters remain constant.

Effects of upstream hydropower operation on riverine particle transport and turbidity in downstream lakes

“…After heavy precipitation, CR A increases to several hundreds to thousands of grams per meter, increasing the river water density and river intrusion depths. During winter, T A drops usually below the temperature of maximum density (T md = 4°C), causing cabbeling instability [Carmack et al, 1979;Shimaraev et al, 1993]. The cold river front mixes with warmer lake water, leading to temperatures close to T md resulting in density-driven intrusions into the deep water.…”

Deep convection in a lake triggered by wind: Two-dimensional numerical experiments with a nonhydrostatic model

“…1) because the observation is largely affected by many other factors such as the bottom topography and the current due to river discharge (Shimaraev et al, 1993), which are excluded from the present experiments. Nevertheless, some similarities are found between both results.…”

“…Lake Baikal in Russia and Crator Lake in U.S.A., deep water ventilation occurs down to the bottom and appears to be caused by deep convection Weiss et al, 1991;McManus et al, 1993;Shimaraev et al, 1993). For example, in Lake Baikal, higher concentrations of dissolved oxygen and chlorofluorocarbons (CFCs) has been observed in the bottom water than in the overlying water .…”

“…Although local wind convergence, internal waves and so on can be candidates for the external forcings, neither deepening of the mixed layer by such phenomena nor deep convection has been observed except that a downward cold plume suggestive of deep convection was found along the bottom slope (Shimaraev et al, 1993;Fig. 1).…”

Holocene and Late Glacial sedimentation near steep slopes in southern Lake Baikal

“…In order to extensively assess environmental impacts on Lake Baikal, their recent and their longer-term history, and their potential influence into the future, it is important to have comprehensive knowledge on the forcing mechanisms and processes, which are responsible for these changes. Research papers of different scientific disciplines have contributed background knowledge on the formation of Lake Baikal and the dynamics of its vast water mass (Goldyrev, 1982;Bezrukova et al, 1991;Shimaraev et al, 1993;Khozhova and Izmest'eva, 1998). It has been shown that biological, physical and geochemical processes all influence biological and geochemical variability in the lake Flower, 1998;Müller et al, 2005;Granina and Callender, 2007;Schmid et al, 2008).…”