PMOD/WRC

Physikalisch-Meteorilogisches Observatorium Davos / World Radiation Center

The "Physikalisch-Meteorologisches Observatorium Davos" (PMOD) was founded in 1907 by Carl Dorno as a privately operated institute with the objective of finding out why tuberculosis patients were curing better in Davos than elsewhere. The most obvious climatic difference of an alpine station compared with one at lower elevations, e.g. the Baltic sea shore where Dorno originated from, is obviously the radiation environment: the direct solar radiation is much more intense whereas the sky radiance of the dark-blue sky is of lower intensity. With this in mind, Dorno began operational measurements of the direct solar irradiance in 1909, initiating the world's longest and still continuing time series of this kind. In addition, he began investigating the biological influences of ultra-violet radiation - then known as Dorno Radiation, and today as UV-B. With his world famous solar and UV radiation measurements he set the corner-stone of the PMOD which has continued his work as an internationally recognized center for research in radiation measurements and instrumentation. Since 1926, PMOD has been part of the SFI private foundation ("Schweizerisches Forschungsinstitut für Hochgebirgsklima und Medizin").

In 1971, the PMOD was designated by the World
Meteorological Organization
(WMO, Geneva) to serve as a World Radiation Center (WRC). The Swiss government offered the WMO to operate the WRC as a contribution to the World Weather Watch Program (WWW )

A further service was added in 1996 with the operation of the World Optical depth Research and Calibration Center (WORCC), a Swiss contribution to the WMO Global Atmosphere Watch program with the following terms of reference:

  • Develop accurate radiometric references for spectral solar radiometry used to determine optical depth (as in the case of the World Radiometric Reference for total solar irradiance radiometry);
  • Develop procedures to ensure world-wide homogeneity of optical depth measurements by e.g. providing transfer standards for precision filter radiometry (formerly called sunphotometry);
  • Develop and test new instrumentation and methods for the determination of optical depth;
  • Implement a trial phase of Precision Filter Radiometers (PFR) at GAW GLOBAL OBSERVATORIES to test methods for optical depth determination and calibration transfer;
  • Develop relevant quality control procedures in cooperation with GAW Quality Assurance/Science Activity Centers;
  • Training of staff to operate Precision Filter Radiometers.

Research Activities

  • Development of instruments and calibration procedures for absolute total and spectral solar and long-wave radiometry;
  • Investigation of the solar total irradiance, its spectral distribution and variability for global climate research, solar physics and helioseismology (VIRGO Experiment);
  • Investigation of radiation in the atmosphere and at the ground to determine its spectral distribution and variability in the UV, for diagnostics of the atmospheric composition and aerosol content as well as to determine the surface radiation budget within the ASRB program.