Surface energy fluxes with the Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER) at the Iowa 2002 SMACEX site (USA)
Surface energy fluxes with the Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER) at the Iowa 2002 SMACEX site (USA)
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DOI：
10.1016/j.rse.2005.05.015
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发表时间：
2005-11
影响因子：
13.5
通讯作者：
A. French;F. Jacob;Martha C. Anderson;W. Kustas;W. Timmermans;A. Gieske;Z. Su;H. Su;M. Mccabe-M.-M
中科院分区：
文献类型：
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作者：
A. French;F. Jacob;Martha C. Anderson;W. Kustas;W. Timmermans;A. Gieske;Z. Su;H. Su;M. Mccabe-M.-M
从空间以高空间分辨率准确估计地表能量通量，有可能改进对土地使用变化对当地环境影响的预测，并提供一种评估当地作物状况的手段。为实现这一目标，需要将基于物理的地表通量模型与高质量遥感数据相结合。来自ASTER传感器的数据特别适合这项任务，因为它收集可见光、近红外和热红外波段的高空间分辨率（15 - 90米）图像。这些波段中的数据产生地表温度、植被覆盖密度和土地利用类型，这些都是地表能量平衡模型评估当地环境条件的关键输入。ASTER是目前唯一收集多谱段热红外图像的卫星传感器，这种能力使对各种地表覆盖类型的地表温度估计具有前所未有的准确性。利用ASTER数据研究地表能量通量，可以直接与地面测量值进行比较，并有助于发现建模的局限性，这两种可能性都是因为ASTER的空间分辨率较高。利用土壤-大气耦合实验（SMACEX）的框架下，在美国爱荷华州中部的一个实验站收集的数据，从ASTER反演地表能量通量。这个实验发生在2002年夏天的异质性农业农田的研究。两种不同的通量估计方法，旨在占空间变异，被认为是：双源能量平衡模型（TSEB）和表面能量平衡算法或土地模型（SEBAL）。ASTER数据显示，空间和光谱分辨率足以获得所需的表面变量作为输入的物理为基础的能量平衡建模。将通量模型的结果相互比较以及与地面测量结果进行比较是很有希望的，通量值通常在150 W m − 2以内。TSEB和SEBAL表现出系统的协议，并响应空间变化的表面温度和植被密度。与地面涡动协方差数据的直接比较表明，TSEB方法是有帮助的稀疏植被的地形。
Accurate estimation of surface energy fluxes from space at high spatial resolution has the potential to improve prediction of the impact of land-use changes on the local environment and to provide a means to assess local crop conditions. To achieve this goal, a combination of physically based surface flux models and high-quality remote-sensing data are needed. Data from the ASTER sensor are particularly well-suited to the task, as it collects high spatial resolution (15–90 m) images in visible, near-infrared, and thermal infrared bands. Data in these bands yield surface temperature, vegetation cover density, and land-use types, all critical inputs to surface energy balance models for assessing local environmental conditions. ASTER is currently the only satellite sensor collecting multispectral thermal infrared images, a capability allowing unprecedented surface temperature estimation accuracy for a variety of surface cover types. Availability of ASTER data to study surface energy fluxes allows direct comparisons against ground measurements and facilitates detection of modeling limitations, both possible because of ASTER's higher spatial resolution. Surface energy flux retrieval from ASTER is demonstrated using data collected over an experimental site in central Iowa, USA, in the framework of the Soil Moisture Atmosphere Coupling Experiment (SMACEX). This experiment took place during the summer of 2002 in a study of heterogeneous agricultural croplands. Two different flux estimation approaches, designed to account for the spatial variability, are considered: the Two-Source Energy Balance model (TSEB) and the Surface Energy Balance Algorithm or Land model (SEBAL). ASTER data are shown to have spatial and spectral resolution sufficient to derive surface variables required as inputs for physically based energy balance modeling. Comparison of flux model results against each other and against ground based measurements was promising, with flux values commonly agreeing within ∼50 W m−2. Both TSEB and SEBAL showed systematic agreement and responded to spatially varying surface temperatures and vegetation densities. Direct comparison against ground Eddy Covariance data suggests that the TSEB approach is helpful over sparsely vegetated terrain.