Field data and numerical modeling were used to investigate the effects of the riverine inflows on the seasonality of the lake mean temperature, thermal structure, and basin-scale internal waves in a tropical Andean reservoir. Lake temperature and external forcing were measured during contrasting hydrological periods modulated by severe cold (2011–2012) and warm (2015–2016) phases of El Niño–Southern Oscillation (ENSO), a major driver of Andes hydrology. The seasonal heat budget of the reservoir was driven by the competing rates of cooling by the inflow and heating through the surface. As the atmospheric heating rate remained roughly constant, the seasonality of the river inflow heat flux drove the seasonal reservoir temperature. The inflow also intervened on the heat transport within the reservoir and, during dry periods, mixed heat downward from the surface layer and introduced heat at intermediate depths such that a thick metalimnion formed that brought the V2H1 mode into resonance with the diurnal wind forcing. During wet periods, the inflow compressed and cooled the metalimnion, tuning the V1H1 mode to resonate with the diurnal wind. It was also observed that large inflows destroyed temporarily coherent basin-scale internal wave motions. Because of the dominant role of the inflow on the seasonal reservoir temperature, changes within the reservoir will be more strongly related to changing temperature and volume of the incoming water than atmospheric forcing as in many large natural lakes.

中文翻译：

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河流流入对热带安第斯水库气候的影响

现场数据和数值模拟被用来研究河流流入对热带安第斯水库中湖泊平均温度、热结构和盆地尺度内波季节性的影响。在厄尔尼诺-南方涛动 (ENSO) 的严寒 (2011-2012) 和暖 (2015-2016) 阶段调节的对比水文时期测量了湖泊温度和外部强迫，这是安第斯山脉水文的主要驱动因素。水库的季节性热量收支是由流入和通过地表加热的竞争冷却速率驱动的。由于大气升温速率基本保持不变，河流流入热通量的季节性驱动着季节性水库温度。流入还干预了水库内的热传输，在干旱时期，从表层向下混合热量并在中间深度引入热量，从而形成厚金属膜，使 V2H1 模式与昼夜风力共振。在潮湿时期，流入压缩和冷却金属膜，调整 V1H1 模式以与昼夜风共振。还观察到大量流入破坏了暂时相干的盆地尺度内部波浪运动。由于流入对季节性水库温度的主导作用，与许多大型天然湖泊中的大气强迫相比，水库内的变化与流入水的温度和体积变化的相关性更强。在潮湿时期，流入压缩和冷却金属膜，调整 V1H1 模式以与昼夜风共振。还观察到大量流入破坏了暂时相干的盆地尺度内部波浪运动。由于流入对季节性水库温度的主导作用，与许多大型天然湖泊中的大气强迫相比，水库内的变化与流入水的温度和体积变化的相关性更强。在潮湿时期，流入压缩和冷却金属膜，调整 V1H1 模式以与昼夜风共振。还观察到大量流入破坏了暂时相干的盆地尺度内部波浪运动。由于流入对季节性水库温度的主导作用，与许多大型天然湖泊中的大气强迫相比，水库内的变化与流入水的温度和体积变化的相关性更强。