MONITORING SUMMER SOLAR ULTRAVIOLET (UV) RADIATION ON THE GROUND LEVEL OVER ARDABIL-SAREIN, NW IRAN

Abstract. The UV radiation level at the Earth’s surface is generally affected by several factors such as time, geographic location, and climate. first observations of solar ever made in NW Iran, obtained June 2019 are reported this work. analysis hourly values irradiances measured study area reveals significant diurnal variation during daylight hours, with lower morning afternoon higher around noon. Mean (A+B) ranged from 2755 to 10434 µW/cm2 an average value being about 7960 µW/cm2. (C) 40 91 76 results a short but intense measurement campaign Ardabil-Sarein indicate trends for geographical latitude, longitude, altitude measurements. intensity associated longitude (r2= 0.15 (A+B); r2= 0.13 (C)). Furthermore, varies local latitude area. There strong linear relationship between trend rising increasing obtained. A decrease zenith (°) was observed. However, correlation azimuth not significant. Understanding influencing near-surface through systematic ground-based will help determine whether long-term changes occur result cloud cover or climate change, how specific it means identifying causes.