Abstract Global lake evaporation is a critical component of the terrestrial water cycle. Accurate quantification of lake evaporation dynamics is of high importance for understanding lake energy budgets, land-atmosphere interactions, as well as regional water availability. However, the accurate quantification of lake evaporation has been hindered by the complexity involved with addressing the heat storage of water bodies. In this study, a new model—the Lake Temperature and Evaporation Model (LTEM)—was developed to simulate lake water temperature profiles, which were then used to calculate heat storage changes and evaporation rates. Inputs for the LTEM include the meteorological and bathymetric data, as well as the Moderate Resolution Imaging Spectroradiometer (MODIS) water surface temperature (WST)—which is the land surface temperature (LST) over water. The MODIS WST was leveraged to constrain the hydrodynamic simulations. Model results over 11 lakes around the world show robust performance of LTEM. The long term average temperature biases range from -0.5 °C to 0.5 °C, and the evaporation rate biases range from -0.19 mm/day to 0.28 mm/day. In particular, it is found that LTEM significantly improves the simulation of the seasonality of lake evaporation rates. The validation results suggest that the averaged coefficient of determination (R2) for the evaporation rate is 0.84, which is 0.28 higher than that obtained when the conventional Penman equation (without heat storage) is used. The volumetric evaporation time series was then calculated as a product of the monthly evaporation rate and lake surface area (derived from MODIS near-infrared image classifications). This study provides an end-to-end framework for quantifying volumetric evaporation for the world’s lakes and reservoirs. It also provides the capability to investigate the thermal dynamics of lake systems, and thus can benefit the various water resources applications across scales.

中文翻译：

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利用 MODIS LST 数据估算湖泊温度剖面和蒸发损失

摘要 全球湖泊蒸发是陆地水循环的重要组成部分。准确量化湖泊蒸发动态对于了解湖泊能量收支、陆地-大气相互作用以及区域水资源可用性非常重要。然而，湖泊蒸发的准确量化受到了解决水体蓄热问题的复杂性的阻碍。在这项研究中，开发了一种新模型——湖泊温度和蒸发模型 (LTEM)——来模拟湖泊水温剖面，然后用于计算蓄热变化和蒸发率。LTEM 的输入包括气象和测深数据，以及中分辨率成像光谱仪 (MODIS) 水面温度 (WST)——这是水面上的地表温度 (LST)。MODIS WST 被用来约束水动力模拟。全球 11 个湖泊的模型结果显示了 LTEM 的强大性能。长期平均温度偏差范围从 -0.5 °C 到 0.5 °C，蒸发率偏差范围从 -0.19 mm/day 到 0.28 mm/day。特别是，发现 LTEM 显着改善了湖泊蒸发率季节性的模拟。验证结果表明，蒸发率的平均决定系数 (R2) 为 0.84，比使用传统 Penman 方程（无蓄热）时获得的系数高 0.28。然后将体积蒸发时间序列计算为月蒸发率和湖表面积的乘积（源自 MODIS 近红外图像分类）。这项研究为量化世界湖泊和水库的体积蒸发提供了一个端到端的框架。它还提供了研究湖泊系统热动力学的能力，因此可以使各种水资源应用受益。