Regional evaporation estimates from flux tower and MODIS satellite data
Regional evaporation estimates from flux tower and MODIS satellite data
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DOI：
10.1016/j.rse.2007.04.015
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发表时间：
2007-02-15
影响因子：
13.5
通讯作者：
Running, Steven W.
中科院分区：
文献类型：
--
作者：
Cleugh, Helen A.;Leuning, Ray;Running, Steven W.
以MODIS遥感数据和地面气象数据为输入，对两种模型估算16天间隔的地表蒸发能力进行了评估。第一种是空气动力学阻力 - 地表能量平衡模型，第二种是彭曼 - 蒙特斯（P - M）方程，其中所需的地表导度是根据遥感叶面积指数估算的。利用来自澳大利亚两个对比鲜明的生态系统（一个凉爽温带的常绿桉树林和一个干湿热带稀树草原）3年的蒸发量和气象测量数据对模型进行了测试。空气动力学阻力 - 地表能量平衡方法失败了，因为辐射表面温度的微小误差会转化为感热的大误差，进而影响蒸发量的估算。P - M模型充分估算了两个生态系统中蒸发量的大小和季节变化（均方根误差 = 27瓦/平方米，决定系数 = 0.74），证明了所提出的地表导度算法的有效性。这一点以及通过能量平衡约束蒸发量估算的能力，表明了P - M方程相对于基于地表温度的模型的优越性。当用更粗空间（0.05度）和时间（每日）分辨率的网格气象数据替代当地测量的输入数据时，P - M模型的性能没有下降。利用P - M方法生成了2001年至2004年澳大利亚的月蒸发气候学数据，以展示这种方法在监测地表蒸发以及构建从1千米到大陆空间尺度的月水量平衡方面的潜力。（c）2006爱思唯尔公司。保留所有权利。
Two models were evaluated for their ability to estimate land surface evaporation at 16-day intervals using MODIS remote sensing data and surface meteorology as inputs. The first was the aerodynamic resistance-surface energy balance model, and the second was the Penman-Monteith (P-M) equation, where the required surface conductance is estimated from remotely-sensed leaf area index. The models were tested using 3 years of evaporation and meteorological measurements from two contrasting Australian ecosystems, a cool temperate, evergreen Eucalyptus forest and a wet/dry, tropical savanna. The aerodynamic resistance-surface energy balance approach failed because small errors in the radiative surface temperature translate into large errors in sensible heat, and hence into estimates of evaporation. The P-M model adequately estimated the magnitude and seasonal variation in evaporation in both ecosystems (RMSE=27 W m(-2), R-2 = 0.74), demonstrating the validity of the proposed surface conductance algorithm. This, and the ability to constrain evaporation estimates via the energy balance, demonstrates the superiority of the P-M equation over the surface temperature-based model. There was no degradation in the performance of the P-M model when gridded meteorological data at coarser spatial (0.05 degrees) and temporal (daily) resolution were substituted for local ly-measured inputs.The P-M approach was used to generate a monthly evaporation climatology for Australia from 2001 to 2004 to demonstrate the potential of this approach for monitoring land surface evaporation and constructing monthly water budgets frorn 1-krn to continental spatial scales. (c) 2006 Elsevier Inc. All rights reserved.