TITLE:
Diurnal and Seasonal Variations of Surface Ozone and Its Precursors in the Atmosphere of Yanbu, Saudi Arabia
AUTHORS:
Hesham A. Al-Jeelani
KEYWORDS:
Ozone, Precursors, Diurnal and Seasonal, Urban, Saudi Arabia
JOURNAL NAME:
Journal of Environmental Protection,
Vol.5 No.5,
April
18,
2014
ABSTRACT:
Surface
ozone (O3) and its precursor’s gases (nitrogen monoxide (NO),
nitrogen dioxide (NO2), nitrogen oxides (NOx), carbon monoxide
(CO), methane (CH4) and non-methane hydrocarbons (NMHCs), and sulfur
dioxide (SO2) were measured in Yanbu, Saudi Arabia from January
2004-December 2004. The annual average concentrations of O3, NO, NO2,
NOx, SO2, CO, CH4, TNMHCs and THC were 22.51 ppb, 15.58
ppb, 17.25 ppb, 23.84 ppb, 6.66 ppb, 165.13 ppb, 3.44 ppm, 0.56 ppm and 3.88
ppm, respectively. The SO2/NOx and SO2/NO2 concentration ratios during the period of study indicate that the mobile
emissions are the predominant sources in yanbu. The diurnal cycles of O3 concentrations revealed highest levels in the daytime and lowest levels in
night time. The diurnal variations of NO, NO2, NOx, SO2,
CO, NMHCs concentrations were similar and showed peaks concentrations linked to
traffic density, boundary layer mixing processes and chemical processes in the
atmosphere. The mean concentrations of O3 in different seasons
follow the order of summer > spring > autumn > winter. In contrary to
O3, NO has higher concentrations in autumn and winter than those in
summer and spring seasons. The highest concentrations of NO2, NOx,
SO2, CO, and TNMHCs were found in autumn and spring, whereas the
lowest concentrations were found in summer and winter. THC and CH4 have no significant change over winter, autumn and summer seasons, while their
concentrations decrease sharply in spring. Although the studied area does not
suffer from NO2, O3, SO2 and CO pollution and
no health risk, comprehensive and long-term air quality management programmes
are needed in order to keep air quality in a good condition.