A Procedure to Correct the Historical Atmospheric Longwave Irradiance Data When the World Reference Is Established with Respect to the International System of Units
Keywords:Atmospheric longwave irradiance, pyrgeometer, SI, ACP, IRIS, WISG
Historical atmospheric longwave irradiance data sets with traceability to the International System of Units (SI) are essential for renewable energy and atmospheric science research and applications. To date, all pyrgeometers used to measure the irradiance are traceable to the interim World Infrared Standard Group (WISG), not to SI units. In 2013, the Absolute Cavity Pyrgeometer (ACP) (Reda et al. 2012) was developed at the National Renewable Energy Laboratory (NREL) to measure the atmospheric longwave irradiance. The ACP has been compared against the InfraRed Integrating Sphere (IRIS), developed by the Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC) (Gröbner 2012). The ACP and the IRIS are absolute instruments traceable to SI units through the International Temperature Scale of 1990. Results of six comparisons between the ACP and the IRIS at different locations have shown that the irradiance measured by WISG pyrgeometers underestimates clear-sky atmospheric longwave irradiance by 2 W/m2 to 6 W/m2 (Gröbner et al. 2014); therefore, once the world reference is established with traceability to SI units, the WISG would be corrected, then used to calibrate field pyrgeometers with traceability to SI units. The following described method is used to correct the historical atmospheric longwave irradiance data sets in anticipation of the WISG scale change.
Gröbner, J., 2012: A Transfer Standard Radiometer for Atmospheric Longwave Irradiance Measurements. Metrologia 49, S105–11, https://doi.org/10.1088/0026-1394/49/2/S105.
Gröbner, J., I. Reda, S. Wacker, S. Nyeki, K. Behrens, and J. Gorman, 2014: A New Absolute Reference for Atmospheric Longwave Irradiance Measurements with Traceability to SI Units. J. Geophys. Res.: Atmos. 119: 7083–90, https://doi.org/10.1002/2014JD021630.
Philipona, R., C. Fröhlich, and Ch. Betz, 1995: Characterization of Pyrgeometers and the Accuracy of Atmospheric Long-Wave Radiation Measurements. Appl. Opt. 34, no. 9 (March 20): 1598–1605, https://doi.org/10.1364/AO.34.001598.
Reda, I. J. Zeng, J. Scheuch, L. Hanssen, B. Wilthan, D. Myers, and T. Stoffel, 2012: An Absolute Cavity Pyrgeometer to Measure the Absolute Outdoor Longwave Irradiance with Traceability to International System of Units, SI. J. Atmos. Sol.-Terr. Phys. 77: 132–43, https://doi.org/10.1016/j.jastp.2011.12.011.
Reda, I., J. R. Hickey, T. Stoffel, and D. Myers, 2002: Pyrgeometer Calibration at the National Renewable Energy Laboratory (NREL). J. Atmos. Sol.-Terr. Phys. 64: 1623–29.
How to Cite
Copyright (c) 2022 Ibrahim Reda, Afshin Andreas, Peter Gotseff
This work is licensed under a Creative Commons Attribution 4.0 International License.