Understanding Lake Residence Time Across Spatial and Temporal Scales: A Modeling Analysis of Lake George, New York USA
Understanding Lake Residence Time Across Spatial and Temporal Scales: A Modeling Analysis of Lake George, New York USA
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DOI：
10.1029/2022wr034168
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发表时间：
2024-02
影响因子：
5.4
通讯作者：
Guillaume A. R. Auger;Michael R. Kelly;Vincent W. Moriarty;K. C. Rose;Harry R. Kolar
中科院分区：
文献类型：
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作者：
Guillaume A. R. Auger;Michael R. Kelly;Vincent W. Moriarty;K. C. Rose;Harry R. Kolar
整个湖的停留时间与各种水质参数有关，包括有害藻类的繁殖。尽管对常用测量的湖泊水质参数的空间变异性进行了观察，但很少关注湖泊中停留时间的空间变异性。在本文中，我们使用水龄作为停留时间的替代指标，并研究了其在美国纽约州乔治湖 10 个不同大小海湾中的时空分布。使用经过验证的水动力模型和水温和水流观测结果，并使用模拟水龄，我们发现大多数海湾的平均停留时间少于 3 天。海湾平均水龄的时间序列显示，由于强风事件，海湾平均水龄会在 1 天内急剧下降。平均空间分布不均匀，只有海湾底层的一小部分年龄明显较大，某些海湾的年龄可能超过 1 周。水龄样线快照表明，强风事件极大地改变了一些海湾水龄的垂直分布，甚至达到了分布反转的程度。海湾水龄的大幅下降与温跃层的变浅和加深有关。我们的结果强调了湖泊内水停留时间的变化如何导致水质属性的显着变化。整个湖泊的停留时间可能无法很好地反映水团的动态，特别是在大型且形态复杂的水体中。
Whole lake residence time has been associated with various water quality parameters, including harmful algal blooms. Despite observations of spatial variability in commonly measured lake water quality parameters, little attention is given to the spatial variability of residence time in lakes. In this paper we use water age as a surrogate for residence time and we examine its spatial and temporal distribution in 10 bays of varying size in Lake George, New York (USA). Using a validated hydrodynamic model against observations of water temperature and water currents, and using simulated water age, we show that the average residence time in most of the bays is less than 3 days. Timeseries of bay‐average water age shows that it can sharply decrease within 1 day due to a strong wind event. The average spatial distribution is shown to be non‐uniform, with only a small section of the bottom layer of the bays having a substantially greater age, which may be more than 1 week in certain bays. Snapshots of water age transects indicate that strong wind events substantially change the vertical distribution of water age in some bays, even to the extent of inverting the distribution. The substantial decreases of water age in the bays were associated with the shallowing and deepening of the thermocline. Our results highlight how variations in water residence times within lakes could introduce substantial variation in water quality attributes. Whole lake residence times may serve as a poor proxy to understand the dynamics of water masses, especially in large and morphologically complex waterbodies.