Radiation measurements are a fundamental part of meteorological observation and climate monitoring. Research has been conducted on solar irradiance at the Physical Meteorological Observatory in Davos (PMOD) since 1907. In 1971, the World Meteorological Organization (WMO) gave the PMOD the additional mandate of serving as the World Radiation Center (WRC). The WRC plays a crucial role in maintaining quality standards in global climate monitoring programmes. The WRC fields of activity are divided into four Sections, in which the measurement of solar radiation is the central focus of each one. While the PMOD/WRC develops new techniques and instruments to measure solar radiation, measured data is analysed and used for instance to investigate Climate Change.
The World Optical Depth Research & Calibration Center (WORCC) develops accurate radiometric references for spectral solar radiometry which are used to determine optical depth. The World Meteorological Organization (WMO) instigated the Global Atmosphere Watch (GAW) program in 1989 as a successor to the Background Air Pollution Monitoring Network (BAPMoN). In 1993 it was recommended that AOD measurements, conducted previously under BAPMoN, should be discontinued until new instruments, methods and protocols could be established to collect AOD data of known and assured quality. Based on a recommendation by GAW experts, the World Optical Depth Research & Calibration Center (WORCC) was established in 1996 at the PMOD/WRC in Switzerland. WORCC has since been advised by the GAW Scientific Advisory Group for Aerosols.
PMODWRC has organized and participated in numerous experimental campaigns with solar measurement instrumentation. It is the PI of the GAW-PFR network of global aerosol optical depth retrievals and coordinates networking actions as COST Action HARMONIA (sun photometer homogenization), leads projects on solar radiation and aerosol Metrology and is part of the European ACTRIS-RI (Aerosol and Cloud research infrastructure) as a unit for the aerosol sun photometry calibration reference group. PMODWRC is participating in the Cloud-aERosol inTeractions & their impActs IN The earth sYstem (CERTAINTY) project dealing with aerosol-cloud-radiation interactions and also leads the Swiss project Race-ECV aiming to contribute towards EarthCARE validation. PMODWRC in collaboration with Beyond/NOA has participated in a number of EU funded projects on solar radiation/energy forecasting (GeoCradle, Eiffel, Eurogeo EShape, Destination Renewable Energy).