Comparative Study of the Influence of Air Pollution on UVI at Maitri in Antarctica and New Delhi in India

Abstract

The influence of air pollution on the erythemal ultraviolet irradiance (UVI) reaching the earth's surface has been investigated at the Indian Antarctic station Maitri and compared with that at New Delhi, the capital of India, over a period of three years from 2005 to 2007. Total ozone column (TOC), surface ozone, NO2 column, middle tropospheric SO2 column, and BrO column are observed to exhibit a deceasing trend at Maitri, having a clean and pristine environment, while UVI and aerosol optical depth at 500 nm exhibit an increasing trend. This negative correlation suggests that O3, NO2, SO2, and BrO act as filters against erythemal ultraviolet irradiance reaching the earth's surface, while the aerosols, which are present in the atmosphere of Maitri, may not be either very effective in filtering out the UVI reaching the earth's surface or may not be large enough to produce measurable effects on UVI. TOC and BrO column are observed to exhibit a deceasing trend at New Delhi, having comparatively higher levels of pollution, while UVI, NO2 column, middle tropospheric SO2 column, surface ozone, and aerosol optical depth at 500 nm exhibit an increasing trend. This suggests that TOC and BrO act as filters against UVI, while NO2, surface ozone, SO2, and aerosols in the atmosphere of New Delhi may not be large enough to produce measurable effects on UVI.