An Application of the Theory of Maximum Entropy Production in Modeling Evapotranspiration

最大熵产生理论在蒸散发模拟中的应用

• 批准号: 0943356
• 负责人: Rafael Bras
• 金额: $ 35.32万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-15 至 2011-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0943356&HistoricalAwards=false
• 关键词: Application; Theory; Maximum; Entropy; Production

An Application of the Theory of Maximum Entropy Production in ModelingEvapotranspiration(NSF Proposal 0943356)PIs: Rafael L. Bras and Jingfeng WangUniversity of California, IrvineAbstractThis project aims at developing an innovative model of evapotranspiration (ET) over land surfaces based on the theory of maximum entropy production (MEP), an emerging theoretical framework for non-equilibrium systems. The effort is guided by promising preliminary results that obtained expressions for ground and sensible heat fluxes over a dry land surface. The research is organized in: (1) theoretical development and (2) observational validation. The central task of the theoretical development is to formulate, based on our best understanding of the turbulent transport in the atmospheric boundary layer (ABL), an expression for the ?thermal inertia for transferring latent heat? that is the key parameter of the dissipation function whose extremization leads to the MEP solution of latent, sensible and ground heat fluxes. We follow three leads in formulating the ?thermal inertia for latent heat?: (1) the turbulent mixing responsible for the transport of sensible heat in the ABL is also responsible for the transport of water vapor, (2) water vapor right above the evaporating surface is in equilibrium with the soil water, and (3) the surface variables of temperature and humidity (as well as stomatal conductance over the canopy) are sufficient to determine the energetics of the evapotranspiration. As a result, the ?thermal inertia for transferring latent heat? is expected to be a function of surface temperature and humidity (and stomatal conductance) for the case of bare soil (canopy). The validation phase of the project has a two-fold objective: (1) validating the MEP model of ET for bare soil and canopy at local scales, and (2) exploring a possible application of the MEP model of ET formulated at local scale (defined as the scales at which the Monin-Obukhov turbulence model applies) to regional scales. Validation of the MEP model at local scales will mostly use archived datasets from previous field campaigns supplemented by additional field measurements whenever needed. Test of the MEP model of ET at regional scales will compare latent, sensible, and ground heat fluxes predicted by the MEP model with the reanalysis datasets using other ET models. Depending on progress, the theoretical development may expand to include the case of water (oceans, lakes, etc.) and snow surfaces. The project, if successfully carried out, will provide a new modeling framework for predicting the land surface energy balance at local scales and hopefully producing improved datasets of surface heat fluxes with global coverage.If successful the results of this effort will provide a completely new method to compute the land surface energy balance that would be parsimonious and require little calibration. The method will be implemented in existing land surface models that are used to make hydro-climatic predictions. Besides engaging doctoral students in the effort, the project will use an existing undergraduate research opportunities program to engage at least one undergraduate student, preferably from a disadvantaged group, in learning energy and hydrologic balances by performing field experiments that could yield supporting data sets. A complete set of instruments to measure energy fluxes and temperature, soil moisture and other hydrologic variables required are available. All students, graduate and undergraduate, will be engaged in presenting their results in appropriate scientific meetings and journals. The University publishes a research journal for undergraduates. The senior investigator is a leader, host and participant of the MESA and CAMP outreach programs housed at the school of engineering of the University of California, Irvine. This provides access to underprivileged students in middle and high schools as well as community colleges. This access will be used to engage interested participants in issues related to hydrology and earth sciences. Mechanisms include visits to schools, receiving students at the university, giving public lectures and sponsoring or supervising project work.

最大熵产生理论在建模撤离（NSF提案0943356）中的应用PIS：加利福尼亚州的Rafael L. Bras和Jingfeng Wanguniversity，Irvineabstelts Ththis Project旨在开发基于陆地的创新模型（ET）的创新模型（ET）基于陆地的创新（ET）。非平衡系统。这项工作是通过有希望的初步结果来指导的，这些结果获得了在干地面上获得地面和明智的热通量表达式的表达。该研究在：（1）理论发展和（2）观察验证中。理论发展的中心任务是根据我们对大气边界层（ABL）中湍流传输的最佳理解，这是？热惯性的表达方式，用于转移潜热？这是耗散函数的关键参数，其极端变化导致潜在，敏感和地面热通量的MEP解决方案。我们遵循三个导线，以制定潜在热热的热惯性？：（1）负责ABL中明智的热量运输的湍流混合也负责水蒸气的运输，（2）蒸发表面上方的水蒸气在蒸发表面上的水蒸气与土壤水和湿气的表面相同（3）均具有稳定的范围（3），以及（3）均具有良好的范围（3），以及均匀的污染物（3）蒸散量。结果，用于转移潜热的热惯性？对于裸露土壤（树冠）的情况，预计将是表面温度和湿度（以及气孔电导）的函数。 该项目的验证阶段具有两个倍的目标：（1）在本地尺度上验证裸土和冠层的ET的MEP模型，以及（2）探索在局部规模上配制的ET的MEP模型的可能应用（定义为Monin-Obukhov湍流模型的规模）。在本地尺度上对MEP模型的验证将主要使用以前的字段广告系列中的存档数据集，并在需要时补充了其他字段测量。在区域尺度上对ET的MEP模型的测试将比较MEP模型预测的潜在，明智和地面热通量与使用其他ET模型的重新分析数据集进行比较。根据进步的不同，理论发展可能会扩展到包括水（海洋，湖泊等）和雪表面的情况。该项目如果成功进行，将提供一个新的建模框架，以预测本地尺度上的土地表面能量平衡，并希望能够在全球覆盖范围内产生改进的表面热通量数据集。该方法将在用于进行水力气候预测的现有陆地表面模型中实施。除了让博士生参与这项工作外，该项目还将使用现有的本科研究机会计划，通过执行可以产生支持数据集的现场实验，使至少一名本科生（最好是来自弱势群体的本科生，最好来自一个处境不利的群体）。一组完整的仪器，用于测量所需的能量通量和温度，土壤水分和其他水文变量。所有的学生，毕业生和本科生，都将在适当的科学会议和期刊中介绍他们的结果。该大学出版了本科生的研究杂志。高级调查员是加州大学欧文分校工程学院的MESA和CAMP外展计划的领导者，主持人和参与者。这为中学和社区大学的贫困学生提供了访问。此访问将用于吸引感兴趣的参与者参与与水文和地球科学有关的问题。机制包括对学校的访问，在大学接待学生，进行公开讲座以及赞助或监督项目工作。