The UV Index was established more than 20 years ago as a tool for sun protection and health care. Shortly after its introduction, UV Index monitoring started in several countries either by newly acquired instruments or by converting measurements from existing instruments into the UV Index. The number of stations and networks has increased over the years. Currently, 160 stations in 25 European countries deliver online values to the public via the Internet. In this paper an overview of these UV Index monitoring sites in Europe is given. The overview includes instruments as well as quality assurance and quality control procedures. Furthermore, some examples are given about how UV Index values are presented to the public. Through these efforts, 57% of the European population is supplied with high quality information, enabling them to adapt behaviour. Although health care, including skin cancer prevention, is cost-effective, a proportion of the European population still doesn't have access to UV Index information.

No abstract

No abstract

Context. The Stark broadening of the spectral lines of the wavelengths 501. 6, 667.8, 728.1, 388.9, 587.6, and 706.5 nm from neutral helium in plasmas are studied theoretically and experimentally. Aims. The aim of this work is to provide information about the connection between the shape and width of spectral lines and the electron density and temperature to be used as a diagnostic tool. Methods. The theoretical calculations were carried out through molecular dynamics computer simulations with noninteracting particles. The experimental measurements were done in a plasma of pure helium generated in an electromagnetically driven T-tube. The plasma diagnostics used previous results about the Stark broadening of the He I 447.1 nm and He I 492.2 nm lines and the coherence between the shape of these spectra and those obtained here. The electron temperature was obtained through a Boltzmann-plot of eight lines of Si II. Results. Several tables of width and shift are provided in a wide range of electron density and temperature. Furthermore, we supply several fitting formulas, which allow calculating the plasma electron density from the measured values of the spectral line widths. The results obtained in the laboratory and in the simulations are compared with the data from the literature.

A numerical model called "NEOPLANTA" for estimating solar UV irradiance and UV index under cloud-free conditions is being developed and tested at the University of Novi Sad in Serbia. In this paper, the model features, calculation procedure, and input parameters are described. Effects of the absorption of UV radiation by O 3 , SO 2 , and NO 2 and absorption and scattering by aerosol as well as the air molecules in the atmosphere are included. The performance of the model has been tested with respect to its capability of UV index, which is a weighted integral between 280 and 400 nm of the solar irradiance reaching the ground. For this test 10-day data measured during the spring and summer in 2003, 2004, and 2005 are used. Data are recorded by the Yankee UVB-1 biometer located at the Novi Sad university campus (45. 33°N, 19.85°E; 84 m MSL). Error analyses indicate that the modeled values agree well with the observations.