Introduction
Professor Carl Dorno (founder of PMOD in 1907), who’s main interest was solar radiation and its relation to bioclimatological effects, investigated the very short wavelength part of direct solar radiation already in his early years at Davos. Spectrally resolved measurements were first performed using photochemical and photometrical methods. In honour of his work, the shortest solar radiation penetrating to the Earth surface, became known as “Dornostrahlung”, the spectral part which is nowadays called solar UV-B radiation. Dorno was a strong advocate of the “Cadmiumzell” which from 1916 to the 1930s was routinely used at Davos for spectrally integrated UV-measurements. The large solar height (seasonal dependency) and altitude dependency of solar UV-radiation was deduced from these measurements among other interesting findings.
Dr. Paul Bener conducted intensive investigations of the UV-radiation field between 1954 and 1976. His spectrophotometric measurements of direct, diffuse and global UV-radiation at Davos, Weissfluhgipfel and Basel, allowed him to investigate the UV part of the solar radiation with regard to solar height, altitude, ozone amount and cloud influence. Bener also performed extensive UV calculations to extrapolate into regions in which measurements could not be performed due to technical or logistical reasons. Assumptions had to be made to cover the full picture for a global UV-climatology. Beners investigations were published in many reports and publications.
From 1975 to 1985, Davos was one of 14 stations of the worldwide UV-network which was maintained by the Temple University School of Medicine (Philadelphia, PA, USA). Robertson-Berger Type-500 broadband UV-Biometers, which integrate over the human skin erythema action spectrum, were used at these stations. The network was unfortunately discontinued due to the lack of funding.