Study of variations in Columnar Ozone Concentration at Rajkot

The ozone data obtained from Total Ozone Mapping Spectrometer (TOMS) and Solar Back scatter Ultra Violet spectrometer (SBUV) on Nimbus 7 satellite have been used to study the variability of the total column amount of ozone and ozone concentration in different atmospheric layers respectively at Rajkot (22.30N, 70.8 0E) over a period from 1980 2004. An examination of the monthly mean values obtained from TOMS indicates a marked seasonal variation with a maximum around June and a minimum around December. The SBUV profile of springtime ozone indicates that the stratospheric ozone concentration at Rajkot has decreased consistently from 1982 to1999. The concentration is found to have increased suddenly in 2000 and further in 2001. Thereafter it decreased in 2002 and again increased in 2003. An insignificant overall downward trend is observed in the total column amount of ozone (0.85%) from 1997 to 2004. Latitudinal variation of ozone from Srinagar to Kanyakumari has also been studied for the year 2003, which indicates an increase in ozone concentration with latitude. The results are discussed in the light of photochemical and dynamical effects