Optimized design and experimental validation of a temperature sensor for surface air temperature observation

Accurate air temperature measurements are demanded for climate change research. However, air temperature sensors installed in a screen or a radiation shield have traditionally resisted observation accuracy due to a number of factors, particularly solar radiation. Here we present a novel temperature sensor array to improve the air temperature observation accuracy. To obtain an optimum design of the sensor array, we perform a series of analyses of the sensor array with various structures based on a computational fluid dynamics (CFD) method. Then the CFD method is applied to obtain quantitative radiation errors of the optimum temperature sensor array. For further improving the measurement accuracy of the sensor array, an artificial neural network model is developed to learn the relationship between the radiation error and environment variables. To assess the extent to which the actual performance adheres to the theoretical CFD model and the neural network model, air temperature observation experiments are conducted. An aspirated temperature measurement platform with a forced airflow rate up to 20 m s−1 served as an air temperature reference. The average radiation errors of a temperature sensor equipped with a naturally ventilated radiation shield and a temperature sensor installed in a screen are 0.42° and 0.23°C, respectively. By contrast, the mean radiation error of the temperature sensor array is approximately 0.03°C. The mean absolute error (MAE) between the radiation errors provided by the experiments and the radiation errors given by the neural network model is 0.007°C, and the root-mean-square error (RMSE) is 0.009°C.

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A Spherical Temperature Sensor Array Design for Near-Surface Atmospheric Temperature Studies

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-d-19-0188.1 ◽

2020 ◽

Vol 37 (8) ◽

pp. 1497-1506

Author(s):

Jie Yang ◽

Qingquan Liu ◽

Feng Ding ◽

Renhui Ding

Keyword(s):

Air Temperature ◽

Temperature Sensor ◽

Sensor Array ◽

Elevation Angle ◽

Surface Air Temperature ◽

Longwave Radiation ◽

Absolute Error ◽

Temperature Error ◽

Near Surface ◽

Surface Precipitation

AbstractThe observation accuracy of the surface air temperature less than 0.1 K is a requirement, stated by the meteorological and climatological community. However, the accuracy of a temperature sensor inside a shield is affected by a number of factors including solar radiation, wind speed, upwelling longwave radiation, air density, sun elevation angle, sun azimuth angle, underlying surface, precipitation, moisture, structure, and coating of the radiation shield. Due to these factors, the temperature error of the temperature sensor may be much larger than 1 K under adverse conditions. To improve the observation accuracy, this paper proposed a spherical temperature sensor array. A series of analytical calculations based on a computational fluid dynamics (CFD) method is performed to verify the design principle of this sensor array. The calculation results show that the temperature error ratio can be assumed as a constant. To verify the accuracy of this sensor array, simulations and observation experiments are conducted. The simulation results show that the mean difference between the temperature provided by this sensor array and the reference air temperature is 0.072 K. The field experiment results show that a root-mean-square error (RMSE) and a mean absolute error (MAE) between the temperature provided by this sensor array and the reference air temperature are 0.173 and 0.153 K, respectively.

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On the USCRN Temperature System

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech1715.1 ◽

2005 ◽

Vol 22 (7) ◽

pp. 1095-1100 ◽

Cited By ~ 10

Author(s):

K. G. Hubbard ◽

X. Lin ◽

C. B. Baker

Keyword(s):

Air Temperature ◽

Temperature Sensor ◽

Measurement Errors ◽

Surface Air Temperature ◽

Future Climate Change ◽

Reference Network ◽

Current Configuration ◽

Detection And Attribution ◽

Temperature And Precipitation

Abstract In 2004 a new aspirated surface air temperature system was officially deployed nationally in the U.S. Climate Reference Network (USCRN) commissioned by the National Oceanic and Atmospheric Administration. The primary goal of the USCRN is to provide future long-term and high-quality homogeneous observations of surface air temperature and precipitation that can be coupled to past long-term observations for the detection and attribution of present and future climate change. In this paper two precision air temperature systems are included for evaluating the new USCRN air temperature system based on a 1-yr side-by-side field comparison. The measurement errors of the USCRN temperature sensor are systematically analyzed, and the components of error attributable to the datalogger, lead wires, fixed resistors, and the temperature coefficient of the resistors are presented. Although the current configuration is adequate, a more desirable configuration of USCRN temperature sensor coupled with the datalogger is proposed as a means of further reducing the uncertainty for the USCRN temperature measurement.

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