Ozone and Spectroradiometric UV Changes in the Past 20 Years over High Latitudes

Abstract This study analyzes changes in solar ultraviolet (UV) irradiances at 305 and 325 nm at selected sites located at high latitudes of both hemispheres. Site selection was restricted to the availability of the most complete UV spectroradiometric datasets of the past twenty years (1990–2011). The results show that over northern high latitudes, between 55° and 70°N, UV irradiances at 305 nm decreased significantly by 3.9% per decade, whereas UV irradiance at 325 nm remained stable with no significant long-term change. Over southern high latitudes (55°–70°S), UV irradiances did not show any significant long-term changes at either 305 or 325 nm. Changes in solar UV irradiances are discussed in the context of long-term ozone and other atmospheric parameters affecting UV variability at ground level.