Air temperature measurement errors in naturally ventilated radiation shields
Air temperature measurement errors in naturally ventilated radiation shields
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DOI：
10.1175/jtech1762.1
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发表时间：
2005-07-01
影响因子：
2.2
通讯作者：
Mahrt, L
中科院分区：
文献类型：
--
作者：
Nakamura, R;Mahrt, L
在估算气温时，考虑了两个系统误差来源。第一个来源是在不同高度的植被表面上标准化测量高度的定义不明确。如果没有这样的标准化，水平气温梯度的评估就会受到气温垂直变化的影响。这种误差在白天不稳定的情况下通常很小，但在夜间随着稳定度的增加而增加。为了减少这种误差，提出使用零面位移高度来标准化测量高度。系统误差的第二个来源是对传感器-屏蔽系统的辐射强迫。在草地上进行了一系列实验，以研究在自然通风的多板屏蔽层中，HOBO Pro热敏电阻的辐射引起的气温估计误差。通过比较机械吸气屏蔽层中铂电阻温度探测器(RTD)传感器测量的空气温度，可以估计该误差的大小。与第一源引起的误差相反，辐射引起的误差随着不稳定性的增加而增加。建立了利用风速和净辐射或短波辐射信息修正辐射温度误差的经验模型。用独立数据检验了模型的稳健性。
Two sources of systematic errors are considered for estimating air temperature. The first source is ambiguity of the definition of the standardized measurement height over vegetated surfaces of varying heights. Without such a standardization, evaluation of the horizontal air temperature gradient is contaminated by the vertical variation of air temperature. This error is generally small in daytime unstable conditions, but increases with increasing stability at night. In an attempt to reduce such error, the use of the zero-plane displacement height for standardizing the measurement height is proposed.The second source of systematic errors is radiative forcing on the sensor-shield systems. A series of experiments is performed over a grass field to investigate the radiatively induced error in the air temperature estimate by the Onset HOBO Pro thermistor in a naturally ventilated multiplate shield. The magnitude of this error is estimated by comparing air temperature measurements by a platinum resistance temperature detector (RTD) sensor in a mechanically aspirated shield. In contrast to the errors resulting from the first source, the radiatively induced error increases with increasing instability. An empirical model is developed for correcting the radiatively induced temperature error using information on wind speed and net or shortwave radiation. The robustness of the model is examined with independent data.