We investigated temporal variations in turbidity in Base Mine Lake, an oil sands pit lake, located in northeast Alberta, Canada. The lake has a surface area of 7.8 km², is 9 m deep, and exhibits seasonal thermal stratification similar to that of natural dimictic lakes. Water turbidity was measured continuously throughout the year with moored sensors, supplemented with turbidity profiles and bottle samples, from sites on the lake. During summer there was a gradual exponential (e-folding time of 25 days) decrease in epilimnetic turbidity due to relatively steady settling of solids from the epilimnion through the thermocline to the hypolimnion. Rapid oscillations (periods of approximately 1 day) in turbidity during summer were due to wind driven internal waves. Convective cooling and wind-shear driven stirring during fall storm events increased the turbidity to an annual high just before ice-on. During these storm events, similarity scaling indicated wind shear imparted greater energy than convective cooling to the turbulence at the base of the water column. Ice suppressed wind forcing and resulted in a rapid decrease in turbidity. The rate of decrease in turbidity following ice-on was initially greater than the rate of decrease in the epilimnion during summer, and then slowed until the under-ice turbidity was a relatively constant value which was sustained during the latter half of the ice-on period. The minimum turbidity during winter was greater than the minimum during summer. Following ice-melt in spring, wind driven stirring increased turbidity until summer stratification began.

中文翻译：

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油砂坑湖中浊度的时间变化。

我们调查了位于加拿大艾伯塔省东北部的油砂坑湖Base Mine湖中浊度的时间变化。该湖的表面积为7.8 km ²，深9 m，并且表现出类似于天然干枯湖泊的季节性热分层。全年都使用停泊的传感器连续测量水的浊度，并补充了湖中站点的浊度分布图和瓶子样品。在夏季，由于固体从上层通过热跃层到下层的沉降相对稳定，上层浊度逐渐减小（电子折叠时间为25天）。夏季，浊度快速振荡（大约1天），这是由风驱动的内部波浪引起的。在秋季暴风雨期间，对流冷却和风切变驱动的搅动使浊度增加到冰上冰冻前的年度最高水平。在这些暴风雨期间，相似标度表示风切变比对流冷却给水柱底部的湍流提供了更多的能量。冰抑制了强迫风，并导致浊度迅速降低。在冰上之后，浊度的降低速率最初大于夏季的上斜率的降低速率，然后减慢直至冰下浊度是一个相对恒定的值，该值在冰上后半段一直保持期。冬季的最小浊度大于夏季的最小浊度。春季冰融化后，风力搅拌增加了浊度，直到夏季开始分层。在冰上之后，浊度的降低速率最初大于夏季的上斜率的降低速率，然后减慢直至冰下浊度是一个相对恒定的值，该值在冰上后半段一直保持期。冬季的最小浊度大于夏季的最小浊度。春季冰融化后，风力搅拌增加了浊度，直到夏季开始分层。在冰上之后，浊度的降低速率最初大于夏季的上斜率的降低速率，然后减慢直至冰下浊度是一个相对恒定的值，该值在冰上后半段一直保持期。冬季的最小浊度大于夏季的最小浊度。春季冰融化后，风力搅拌增加了浊度，直到夏季开始分层。