Open AccessOzone ( O 3 ) ambient levels as a secondary airborne precursor in Fahaheel urban area, the State of Kuwait
Author(s) -
AlQassimi Masumah,
AlSalem Sultan Majed
Publication year - 2020
Publication title -
atmospheric science letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.951
H-Index - 45
ISSN - 1530-261X
DOI - 10.1002/asl.983
Subject(s) - daytime , ozone , atmospheric sciences , environmental science , air pollution , meteorology , chemistry , environmental chemistry , geography , physics , organic chemistry
Two years of continuous monitoring data over two time‐spans (2004–2005 and 2014–2015) were used to investigate the relationship between ozone (O 3 ) and nitrogen oxides (NO X ≈ NO + NO 2 ) in Fahaheel urban area (Kuwait). Their relationship was used to understand their chemical reactions and the NO 2 and O 3 concentration ratio to gain an insight into the sources of total atmospheric oxides (O X = O 3 + NO 2 ) levels. A Chemical Mass Balance (CMB) model was developed to detect likely point sources around the monitoring station and quantify their contribution to the overall air pollution load. Hourly diurnal variations in O 3 ground level concentrations during weekends showed a slight increase in O 3 levels. In addition, it was observed that overall hourly average O 3 concentration reached higher levels during weekdays and weekends in 2004–2005 compared to 2014–2015. The concentration of photochemical oxidants (e.g., O 3 and NO 2 ) can be decreased by controlling the emissions of their precursors; NO X and VOCs. The net effect of NO X emissions on O 3 concentrations was negative with a weak exponential decline correlation between NO X and O 3 , indicating Fahaheel urban area's VOC‐sensitive characteristics. For all years considered, the slopes of the linear O X –NO X relationships were higher during daytime compared to night‐time, showing that NO 2 oxidations were dominant during daytime and that O 3 net production was high. The study also showed the high NO X oxidation level and the possible presence of O 3 net production. The slopes during night‐time indicated that NO 2 consumption exceeded its formation rate. During day and night‐time, the NO 2 /NO X ratio was found to decline significantly as newly emitted NO X increased, supporting the area's VOC‐sensitive nature. By setting up a CMB model around the Fahaheel receptor point, it was revealed that downstream petroleum facilities have been the major contributor to pollutants environmental load over the years.