ULTRAVIOLET-RADIATION RECEIVED IN ANTARCTICA IN COMPARISON WITH THE INDIAN REGION

The decrease in atmospheric ozone over Antarctica during September-October 1987 implies enhanced u.v. radiation received at the ground in the region of the ozone hole. At the ozone hole in Antarctica the decrease in total ozone is enormous and sometimes the ozone level reaches as low as 120-130 DU, whereas the normal value of total ozone is around 300 DU. The decrease in ozone will not only increase u.v.B radiation several-fold but will also shift the cut-off wavelength to lower wavelengths. A model calculation for u.v.B radiation reaching ground level for different total ozone content (100-340 DU) has been carried out for several solar zenith angles appropriate to Indian as well as Antarctic stations. The u.v.B radiation received at Antarctica during the ozone-hole period are comparable to our equatorial stations over the summer period.