The Variability in the Atmospheric Total Ozone over Kathmandu Measured with Brewer Spectrophotorneter

  • N. P. Chapagainl Department of Physics Patan Multiple Campus, Tribhuvan University Lalitpur
  • S. Gurung Central Department of Physics Tribhuvan
  • S Lal Atmospheric and Aeronomy Division PRL., Ahmedabad

Abstract

Measurements of atmospheric total ozone over Kathmandu (27.67oN, 85.295oE) were carried out with a Brewer spectrophotometer from February 2001 through February 2002. The Brewer ozone data and total ozone mapping spectrometer (TOMS) ozone data were analyzed to study the daily and seasonal variations of total ozone over Kathmandu. The measurements showed that total ozone values were low in winter season and high in summer and spring seasons. The monthly average ozone concentration over Kathmandu was maximum (305 D.U.) in May and minimum (241 D.U.) in December. There are significant correlations between Brewer ozone measurements and TOMS ozone data. The differences between the two results are up to 7% of the mean ozone content. The low ozone concentration could be due to chemical and dynamic destruction processes related to low temperature and less active photochemical reaction as less intense solar radiation are received during December.Measurements of atmospheric total ozone over Kathmandu (27.67oN, 85.295oE) were carried out with a Brewer spectrophotometer from February 2001 through February 2002. The Brewer ozone data and total ozone mapping spectrometer (TOMS) ozone data were analyzed to study the daily and seasonal variations of total ozone over Kathmandu. The measurements showed that total ozone values were low in winter season and high in summer and spring seasons. The monthly average ozone concentration over Kathmandu was maximum (305 D.U.) in May and minimum (241 D.U.) in December. There are significant correlations between Brewer ozone measurements and TOMS ozone data. The differences between the two results are up to 7% of the mean ozone content. The low ozone concentration could be due to chemical and dynamic destruction processes related to low temperature and less active photochemical reaction as less intense solar radiation are received during December.