Association of Agrometeorologists

UV-B radiation in the tropical monsoon climates

G.S.L.H.V. PRASADA RAO, C. S. GOPAKUMAR and K. N. KRISHNAKUMAR

The UV-B radiation was of the order of more than one MED/hr between 10.30 a.m. and 2.30 p.m., reaching to its maximum of more than two and two-and-a-half MED/hour for about two to three hours during the peak noon hours. It crossed even more than 3MED/hr on 12.9.2002. It was high in the year 2002 when compared to that of 2003, 2004 and till June, 2005. Interestingly, the intensity of UV-B radiation was high (29.8%) in the range of more than 2MED/hr during September. Again, it was more so in the year 2002. Whether high UV values in 2002 could be due to all India drought? All the UV phenomena could be attributed to low level of ozone in addition to meteorological factors. Hence, it is suggested that protective measures round-the- year against the sun rays between 10.30 a.m. to 2.30 p.m. may be adapted to avoid the high intensity of UV-B radiation under the tropical monsoon climate since it has harmful effects on living organisms over the Earth’s surface.

UV-B radiation,Minimum Erythema Dose, Ozone depletion