Characteristics of vertical profile of ozone near the equator

Abstract

Although ozone is rare in several vital roles which the atmosphere, it has depend on vertical distribution of the gas. Consequently, the major objectives of this study were to determine the vertical distribution and dynamics of ozone. An attempt was also made to determine the influence of meteorological parameters on the vertical profile of ozone. Measurements of the primary data that were used to compute the vertical profiles of ozone were obtained by the use of Dobson ozone spectrophotometer No. 18. The instrument is stationed at Chiromo campus , University of Nairobi (1° S, 36° E) at an altitude of 1710 m above sea level. The data were collected for six months (November 1995-April 1996) that represented a hot and a cold season. The primary data were subjected to the new Umkehr inversion algorithm to yield the vertical profiles of ozone. To investigate the general vertical distribution of ozone, arithmetic average of ozone quantity in each layer over the entire duration of the study was computed. An investigation of the dynamics of ozone was realized by studying the monthly variation of ozone in each layer. This investigation was further enhanced by analyzing the ozone standard deviations. The degree of relationship between ozone profiles and some meteorological parameters that included long-term mean tropopause height, tropopause temperature, temperature wind speed wind direction at various levels was carried out. Subjection of raw data to the new Umkehr inversion algorithm yielded 34 Umkehr observations. ozone profiles out of 65 days of The average vertical profile of ozone indicated low and high ozone concentration in the troposphere and stratosphere respectively. About 10.4% of ozone was located below 12.5 km whereas the remaining amount (89.6%) was above this level. Analysis of ozone variability in each layer showed three distinct patterns. These patterns were associated with the three vertical cells (Lower, middle and upper cells) . Highest negative spearman rank correlation coefficients between ozone amount and tropopause height were obtained in layers 4 and 5. Ozone correlation with tropopause temperature indicated high coefficients in layers 3, 4, and 5 relative to other layers. Relationship between temperature and ozone in layers 1- 2 and layers 3-5 depicted positive and negative correlations respectively. Correlation between zonal wind speed and ozone quantity in layers 1-5 indicated variability which was associated with varying wind directions.