Vertical profile variations of NO sub(2) and O sub(3) using slant column density observations during twilight period

• Published in: Indian journal of radio & space physics 1999-01, Vol.28 (6), p.291-301
• Main Authors: Londhe, AL, Bhosale, C S, Meena, G S, Jadhav, D B, Gil, M, Puentedura, O, Yela, M
• Format: Article
• Language: English
• ISSN: 0367-8393

An algorithm developed to derive the vertical profiles of atmospheric species from their slant column density measurements using twilight spectroscopy is discussed. The algorithm has been tested by using the slant column density measurements at polar station, Reykjavik (64 degrees N, 22.6 degrees W) and tropical station, Pune (18.53 degrees N, 73.85 degrees E). The vertical profiles of NO sub(2) and O sub(3) are retrieved by considering slant column densities for ten different solar zenith angles and ten different atmospheric layers of equal thickness. These vertical profiles are used to differentiate the tropospheric and stratospheric contribution of NO sub(2) and O sub(3) . The observations of NO sub(2) at polar station and at tropical station showed frequent higher values of tropospheric concentrations due to pollution episodes and are not correlated with stratospheric NO sub(2) and O sub(3) . The correlation between total column density variations of NO sub(2) and O sub(3) is not observed; however, the stratospheric variations of NO sub(2) and O sub(3) showed good correlation.