Variations of Ground-level Ozone Concentration in Malaysia: A Case Study in West Coast of Peninsular Malaysia

Hourly ground ozone concentration, measured from the monitoring stations in the West Coast of Peninsular Malaysia for the period of 10 years (2003-2012) were used to analyse the ozone characteristic in Nilai, Melaka and Petaling Jaya. The prediction of tropospheric ozone concentrations is very important due to the negative impacts of ozone on human health, climate and vegetation. The mean concentration of ozone at the studied areas had not exceeded the recommended value of Malaysia Ambient Air Quality Guideline (MAAQG) for 8-hour average (0.06 ppm), however some of the measurements exceeded the hourly permitted concentration by MAAQG that is 0.1 ppm. Higher concentration of ozone can be observed during the daytime since ozone needs sunlight for the photochemical reactions. The diurnal cycle of ozone concentration has a mid-day peak (14:00-15:00) and lower night-time concentrations. The ozone concentration slowly rises after the sun rises (08:00), reaching a maximum during daytime and then decreases until the next morning