Volume 13, No. 6, December 2013, Pages 1712-1722 PDF(763 KB)
Spatial Distribution and Temporal Variation in Ambient Ozone and Its Associated NOx in the Atmosphere of Jeddah City, Saudi Arabia
Ibrahim A. Hassan1,2, Jalal M. Basahi2,3, Iqbal M. Ismail2,4, Tutki M. Habeebullah5
1 Faculty of Science, Alexandria University, 21526 El Shatby, Alexandria, Egypt
2 Centre of Excellency in Environmental Studies (CEES), King Abdulaziz University, 80216, Jeddah 21589, Saudi Arabia
3 Department of Hydrology & Water resources Management, Faculty of Environment, Meteorology and Arid Land Agriculture, King Abdulaziz University, Jeddah, Saudi Arabia
4 Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah 21569, Saudi Arabia
5 Haj Research Institute, Umm Al-Qura University, P.O. Box 6287, 21955 Makkah, Saudi Arabia
Concentrations of ambient ozone (O3) and nitrogen oxides (NOx) were measured continuously for a period of 12 months in the city of Jeddah from December 2011 to December 2012. Meteorological parameters, wind speed, temperature, and relative humidity were also monitored. Concentrations of ground O3 were found to be highly dependent on the NOx diurnal cycle and wind speed. Nitrogen oxides were found to exceed air quality standards, especially in industrial sites, while O3 concentrations were found to exceed 40 ppb, averaged over 1 h, on more than 24% of the measured days in the rural sites. Furthermore, they exceeded 30% in all other areas (i.e., the urban ones).
O3 and NOx were inversely related. The highest average NOx concentration (96 ppb) occurred in a rural area downwind of a desalination plant, while the average O3 concentration peaked in a rural area upwind of a desalination plant, reaching 63.5 ppb, although it also reached 72.6 in another rural area, and we consider this latter result as the background figure in the present study. The seasonal variations of O3 were more distinct than those of NOx. To the best of our knowledge, this is the first report providing comprehensive background information on air quality in an arid area of the developing world.
Ambient ozone; Nitrogen oxides; Seasonal variation; Air quality; Jeddah.