Theme 4: Radiation ECVs ~ Surface based radiation networks
The objective of Theme 4: Radiation ECVs is to develop instrumentation and standards for traceable climate quality measurements, including temperature of the Mesopause and thermal infrared sky radiance, from surface-based networks such as those operated under the WMO and UN, e.g. NDMC.
The artefact-based WRR (World Radiometric Reference) is due to be to replaced by CSAR (an SI standard) after having participated in two WMO comparisons. However, for full acceptance, work to operationalise and remove associated uncertainties of the measurement of window transmittance and diffraction is required. Other scales, such as . WISG (World Infrared Standard Group) received attention in MetEOC-3, that designed a calibration source. This source needs full characterisation before calibrating the WISG radiometers.
MetEOC-4 will make devise spectral and spatially resolved measurements of infrared sky radiance, to support understanding of discrepancies between pyrgeometer types and unexplained dependence on atmospheric opacity. A new pyrgeometer will be designed and built.
MetEOC-4 will extend traceability and performance to the full NDMC (Network for the Detection of Mesopause Change). This will be combined with a complementary space measurement of the mesopause using a next-generation spectrometer, on-board a CubeSat, to be fully calibrated in this project.