Abstract

In the present work we analyze the UV index (UVI), based on the solar erythemal irradiance incident over Santiago de Chile. Ground measurements were done continuously from 1995 to 2009 each minute, employing a multiple narrowband PUV-510 radiometer centred at 305, 320, 340 and 380 nm with a 10 nm bandwidth. The monthly mean UVI for all the considered period varies from a maximum value of 9.5 in January (near Southern Hemisphere Summer solstice) to a minimum of 1.4 in June (SH winter solstice). The monthly mean trend from April to August is negative, which seems to be produced by the large aerosol contamination in these months. The time series of monthly UV index data was applied to the development of the forecast of this index, which is informed daily by the Faculty of Medicine, University of Chile. A test of the predictions for October 2009-February 2010, shows very good agreement of the relative difference with respect to measurements, considering the maximum (5.0 %) as well as the mean (4.6 %) values, one hour around noon for clear sky.