• ARM SGP

The Atmospheric Radiation Measurement Program (ARM) Near-Surface Observation Dataset came from the ARM Cloud and Radiation Test Bed site (34◦–39◦N and 94.5◦–100.5◦W). The average elevation is 314 m. The surface skin temperature used in this paper is observed at 60-sec intervals at the Central Facility (36.6◦N, 97.48◦W) of the Southern Great Plains (SGP) site. The instrument used to observe the skin temperature is the Infrared Thermometer (IRT). It is a ground-based radiation pyrometer that measures the equivalent blackbody brightness temperature of the scene in its field of view. The downwelling version has a narrow field of view for measuring sky temperature and detecting clouds. The upwelling version has a wide field of view for measuring the narrowband radiating temperature of the ground surface (https://www.arm.gov/capabilities/instruments/irt). Time series and scatter plots are produced and inspected to compare surface temperature measured by the IRT and a precision infrared radiometer (PIR). The temperature measuring range is from 173 to 473 K. The accuracy is the greater value of a) ±0.5 K + 0.7% of the temperature difference between the internal reference temperature and the object measured or b) the temperature resolution. The spectral sensitivity is from 9.6 to 11.5 µm [43].
