A two-source time-integrated model for estimating surface fluxes using thermal infrared remote sensing
A two-source time-integrated model for estimating surface fluxes using thermal infrared remote sensing
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DOI：
10.1016/s0034-4257(96)00215-5
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发表时间：
1997-05-01
影响因子：
13.5
通讯作者：
Mecikalski, JR
中科院分区：
文献类型：
--
作者：
Anderson, MC;Norman, JM;Mecikalski, JR
我们提出了一个业务的两个源（土壤+植被）模型，用于评估的表面能量平衡的辐射表面温度（T-RAD）的时间变化率的测量在早上的时间。该模型由一个双源表面组件描述T-RAD和显热通量之间的关系，再加上时间积分组件连接表面显热与行星边界层发展。通过将地面温度和边界层温度随时间变化的行为与从地面到大气的显热通量联系在一起，消除了对近地面空气温度的辅助测量的需要。当远程获取T-RAD时，这是一个显著的好处。空气温度可以强烈耦合到当地的生物物理表面条件，如果一个模型使用的表面空气和亮度温度测量不搭配，能量通量估计可能会显着损坏。此外，因为这个模型只使用辐射温度的时间变化，而不是绝对温度，在T-RAD的时间无关的偏差，造成的大气效应或其他来源，不影响估计通量;只有随时间变化的校正部分需要计算。该算法还分解成它的土壤和植被的贡献的表面辐射温度，因此，T-RAD的角度依赖性可以从一个单一的视角T-RAD的观测预测。这种能力对于准确解释极轨道和地球同步卫星的非天底测量至关重要。该模型的性能进行了评估，在两个大规模的现场实验中收集的数据进行比较：第一个国际卫星陆地表面气候学项目现场实验，在堪萨斯的Konza草原和周围进行，季风'90实验，在亚利桑那州南部的核桃沟流域的半干旱牧场进行。这两个比较产生的不确定性，实现了那些需要空气温度作为输入和测量误差的标准微气象方法通量估计的模型。简要概述了在区域或大陆尺度上应用双源时间积分模式的战略。(C)Elsevier Science Inc.，1997.
We present an operational two-source (soil+vegetation) model for evaluating the surface energy balance given measurements of the time rate of change in radiometric surface temperature (T-RAD) during the morning hours. This model consists of a two-source surface component describing the relation between T-RAD and sensible heat flux, coupled with a time-integrated component connecting surface sensible heating with planetary boundary layer development. By tying together the time-dependent behavior of surface temperature and the temperature in the boundary layer with the flux of sensible heat from the surface to the atmosphere, the need for ancillary measurements of near-surface air temperature is eliminated. This is a significant benefit when T-RAD is acquired remotely. Air temperature can be strongly coupled to local biophysical surface conditions and, if the surface air and brightness temperature measurements used by a model are not collocated, energy flux estimates can be significantly corrupted. Furthermore, because this model uses only temporal changes in radiometric temperatures rather than absolute temperatures, time-independent biases in T-RAD, resulting from atmospheric effects or other sources, do not affect the estimated fluxes; only the time-varying component of corrections need be computed. The algorithm also decomposes the surface radiometric temperature into its soil and vegetation contributions; thus the angular dependence of T-RAD can be predicted from an observation of T-RAD at a single view angle. This capability is critical to an accurate interpretation of off-nadir measurements from polar orbiting and geosynchronous satellites. The performance of this model has been evaluated in comparison with data collected during two large-scale field experiments: the first International Satellite Land Surface Climatology Project field experiment, conducted in and around the Konza Prairie in Kansas, and the Monsoon '90 experiment, conducted in the semiarid rangelands of the Walnut Gulch Watershed in southern Arizona. Both comparisons yielded uncertainties comparable to those achieved by models that do require air temperature as an input and to measurement errors typical of standard micrometeorological methods for flux estimation. A strategy for applying the two-source time-integrated model on a regional or continental scale is briefly outlined. (C) Elsevier Science Inc., 1997.