Vertical ozone variation in the lower troposphere of Delhi.

Measurements of ozone in the urban environment of Delhi were carried out at ground level and heights of 23m, 51m, 117m and 153m at four different sites synoptically during 1989-90. A considerable ozone build up was observed all over Delhi and a significant vertical variation in its concentration was observed at all sites. At any given time O3 levels were lowest at ground level and invariably increased with increasing distance from the ground.