The resource serves monthly, daily or hourly values of UV clear and all sky radiation on a global scale. Hourly values are calculated and summed to daily or monthly values.
General input variables.
1. Spectral part of UV: UVA, UVB or Erythemal clear sky (cs) and all sky (as) radiation.
2. Ozone [DU] (fix value); if not set, mean values are taken.
3. Angstrom Beta (fix value); if not set, mean values are taken.
4. Water vapour [cm] (fix value); if not set, mean values are taken.
5. Angstrom Beta (optional).
6. Ozone (optional).
7. Water vapour (optional).
8. Linke turbidity for airmass 2 (optional).
9. Day: Day of month (if output of only one day is wished).
The resource accesses the databases of SODA Linke turbidity for airmass 2 (maps: January, February, March, April, May, June, July, August, September, October, November, December) , water vapour in cm, based on NASA NVAP data 1987-96, (maps: January, February, March, April, May, June, July, August, September, October, November, December) and Ozone [D.U.], based on GOME data 1996-2000: January, February, March, April, May, June, July, August, September, October, November, December). The standard deviation of Ozone during the 5 years is shown for 4 months in the following maps: January, April, July, October. If not given, beta is calculated with TL and water vapour as input. If water vapour and beta is given, TL is calculated. The UV parts are calculated according a new set of algorithms based on smart2 calculations.
This resource makes use of a slightly changed clear-sky model of the European Solar Radiation Atlas (see the ESRA handbook , volume 2). It simulates the hourly irradiances in W.m-2 under clear skies for any geographical location, any day and any elevation.
The clear-sky model is also described in the following article: Rigollier C., Bauer O., Wald L., 2000. On the clear sky model of the 4th European Solar Radiation Atlas with respect to the Heliosat method. Solar Energy, 68(1), 33-48.