Fluctuational analysis of nighttime ground level Ozone (03) concentration due to variations in hourly relative humidity

Ground level ozone (03) is not emitted directly into the atmosphere. It results from photochemical reactions between precursors and influenced by meteorological factors such as relative humidity and temperature. Therefore, this study aimed at investigating the influence of relative humidity and temperature in the fluctuation and transformation of 03 Hourly monitoring data of 03, relative humidity and temperature in Shah Alam from 2006 to 2010 were acquired from the Department of Environment (DoE) which then was extract according for nighttime 03 data. Monitoring for three days has been carried out in Shah Alam for primary data collection. Both primary and secondary data were analyzed using descriptive statistics, box and whisker plot, time series and diurnal plot as well as multiple linear regressions (MLR). The result showed that minimum 03 concentration was 0 ppb during 2006 to 2010 year. Meanwhile, the maximum 03 concentration was 91 ppb in 2009.The diurnal pattern of 03 concentration has higher amount during daytime rather than nighttime. This variation between day and night generally coincides influenced by relative humidity and temperature. MLR analysis was use for modeling the 03 concentration. MLR models showed that variations in ozone concentrations were attributed to variation of few meteorological parameters with R2≈O.299. As conclusion, lower humidity increased the amount of ground level ozone concentration and increasing amount of ground level ozone concentration is influence by the higher temperature of its surrounding.