A Web-based tool for UV irradiance data: predictions for European and Southeast Asian sites

There are a range of UV models available, but one needs significant pre-existing knowledge and experience in order to be able to use them. In this article a comparatively simple Web-based model developed for the SoDa (Integration and Exploitation of Networked Solar Radiation Databases for Environment Monitoring) project is presented. This is a clear-sky model with modifications for cloud effects. To determine if the model produces realistic UV data the output is compared with 1 year sets of hourly measurements at sites in the United Kingdom and Thailand. The accuracy of the output depends on the input, but reasonable results were obtained with the use of the default database inputs and improved when pyranometer instead of modeled data provided the global radiation input needed to estimate the UV. The average modeled values of UV for the UK site were found to be within 10% of measurements. For the tropical sites in Thailand the average modeled values were within 1120% of measurements for the four sites with the use of the default SoDa database values. These results improved when pyranometer data and TOMS ozone data from 2002 replaced the standard SoDa database values, reducing the error range for all four sites to less than 15%.