Effect of Monsoonal Period toward Night-time Ground Level Ozone in East Coast Malaysia

Abstract

Abstract This study aims to identify the effect of monsoonal period toward nighttime ground level ozone in East Coast Malaysia depending on different land use area which is industrial and urban areas. The concentration of O3, NO, NO2 temperature (T), relative humidity (RH) and wind speed (WS) were used and collected from Air Quality Division of the Department of Environment, Malaysia. The data proceeded in descriptive analysis and statistical analysis. Temperature, relative humidity and wind speed parameters (symbol of East Coast Monsoonal period), was compared with O3, NO and NO2 concentration with Pearson correlation analysis. During nighttime, O3 concentration continuously decreasing starting at 7 p.m. promotes by chemical removal and other removal processes. The highest nighttime O3 concentration was recorded 65 ppb (Kemaman) with the lower nighttime ozone achieved zero value. Meanwhile, nighttime O3 concentration in Kota Baharu (nighttime) was recorded lower with maximum (612 ppb) and mean (9.15±8.60 ppb) compared to Kemaman. The temperature and relative humidity correlation with O3 concentration in both locations shown different correlation as Kemaman - 0.149 and 0.212 while Kota Baharu exhibited 0.137 and -0.159. Meanwhile, wind speed has a positive correlation in both locations as Kemaman is 0.388 and Kota Baharu is 0.462 which indicates wind was a factor that induces ozone formation as ozone was transported to the monitoring area. Therefore, NO, NO2, T, RH and WS was not the only factor influences ozone depletion during nighttime as the correlation display was lower.