Air-water exchange and energy flux paths in small lakes

小湖泊中的空气-水交换和能量通量路径

• 批准号: 326125489
• 负责人: Professor Dr. Andreas Lorke
• 金额: --
• 依托单位: Department of Physics
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/326125489?language=en
• 关键词: Air; water; exchange; energy; flux

Wind-induced water motions are an important physical characteristics of lakes and play a vital role in their ecology and biogeochemistry. Wind stress acting at the water surface generates a turbulent mixing layer, surface waves, large-scale flow structures as well as internal waves, which can convey energy to greater depths. The surface momentum transfer and the corresponding intensity of boundary-layer turbulence also affects the exchange of heat and dissolved gases between the lake surface and the atmosphere as well as the rate of evaporation. The processes which control air-water exchange have mainly been studied in the ocean and at high wind speeds. Not much is known about the rate of momentum transfer and its interrelation to other transfer coefficients in small lakes, where the wind speed and fetch length are typically small. In this project, we compile recently conducted atmospheric eddy-covariance (EC) measurements of momentum, heat, water vapor and gas fluxes over 10 different small lakes. This unique data set will be used to analyze the dependence of the momentum transfer from wind to water on wind speed and fetch length and to derive mechanistic relationships between the different transfer coefficients. The energy flux paths within lakes will be studied by complementing ongoing atmospheric EC measurements with extensive measurements of waves, currents and turbulence in three lakes. We will analyze the partitioning of kinetic energy into different types of flows and its fate from generation to dissipation as a function of wind speed, lake size and vertical density stratification. As a result, we provide a comprehensive mechanistic understanding of energy flux paths in small lakes in relation to atmospheric forcing. The project findings will improve current capabilities for modelling and predicting lake-atmosphere interactions and will contribute to a number of up-to-date research questions in biogeochemistry and freshwater ecology.

风引起的水体运动是湖泊的一个重要物理特征，在湖泊生态和地球化学中起着重要作用。作用在水面上的风应力产生湍流混合层、表面波、大尺度流动结构以及内波，它们可以将能量传递到更深的深度。表面动量转移和相应的边界层湍流强度也影响湖面和大气之间的热量和溶解气体的交换以及蒸发速率。控制空气-水交换的过程主要是在海洋和高风速下研究的。在小湖泊中，风速和取水长度通常较小，关于动量传递率及其与其他传递系数的相互关系知之甚少。在这个项目中，我们汇编了最近进行的大气涡动相关（EC）测量的动量，热量，水汽和气体通量超过10个不同的小湖泊。这个独特的数据集将被用来分析从风到水的动量转移对风速和取风长度的依赖性，并推导出不同转移系数之间的机械关系。湖泊内的能量通量路径将通过补充正在进行的大气EC测量与波，电流和湍流在三个湖泊的广泛测量进行研究。我们将分析动能划分成不同类型的流和它的命运从产生到耗散作为风速，湖泊大小和垂直密度分层的函数。因此，我们提供了一个全面的机械理解的能量通量路径在小湖泊的大气强迫。该项目的研究结果将提高目前模拟和预测湖泊-大气相互作用的能力，并将有助于解决地球化学和淡水生态学方面的一些最新研究问题。

项目成果

Variable Physical Drivers of Near‐Surface Turbulence in a Regulated River

• DOI: 10.1029/2020wr027939
• 发表时间: 2021-11
• 期刊: Water Resources Research
• 影响因子: 5.4
• 作者: S. Guseva;M. Aurela;A. Cortés;R. Kivi;E. Lotsari;S. Macintyre;I. Mammarella;A. Ojala;V. Stepanenko

Energy Flux Paths in Lakes and Reservoirs

湖泊和水库中的能量通量路径

• DOI: 10.3390/w13223270
• 发表时间: 2021
• 期刊: Water
• 影响因子: 3.4
• 作者: Guseva;Casper
• 通讯作者: Casper