The reported study examines the diurnal and seasonal variations of tropospheric ozone and its precursors in Bangalore,India,from January to December 2020,and explores the impact of meteorological parameters and the ve...The reported study examines the diurnal and seasonal variations of tropospheric ozone and its precursors in Bangalore,India,from January to December 2020,and explores the impact of meteorological parameters and the ventilation coefficient(VC)on ozone levels.Tropospheric ozone,a significant secondary pollutant,poses a major environmental and health challenge in urban areas.The study focuses on ozone,nitrogen oxides(NO and NO2),Sulphur dioxide(SO2),and carbon monoxide(CO),revealing that ozone peaks in the early afternoon due to solar radiation,while precursor pollutants show morning and evening peaks linked to traffic emissions.Higher ozone levels occur in winter(due to reduced boundary layer height)and summer(due to increased photochemical activity),while the monsoon period shows the lowest levels due to the washout effect.The VC values are generally higher during the day(587 m^(2)/s)compared to night(246 m^(2)/s),with the highest recorded in summer(1,935 m^(2)/s)and the lowest in the post-monsoon season(209 m^(2)/s).Higher VC enhances pollutant dispersion,while lower VC leads to accumulation.However,surface ozone concentrations increase with higher VC due to photochemical processes.The findings highlight the complex interplay of meteorology,emissions,and boundary layer dynamics,informing strategies for urban air quality management.展开更多
In the urban atmosphere of Bengaluru, various volatile organic compounds(VOCs), particularly Benzene,Toluene, Ethylbenzene, and Xylene(BTEX), have shown an increasing trend in concentration. The present research was c...In the urban atmosphere of Bengaluru, various volatile organic compounds(VOCs), particularly Benzene,Toluene, Ethylbenzene, and Xylene(BTEX), have shown an increasing trend in concentration. The present research was conducted during summer and monsoon seasons, focusing on Kadubeesanahalli, a high-traffic area within the Bengaluru Metropolitan City. Hourly sample data was collected using a BTEX analyzer(Model GC955-600) and subsequently transformed into daily, monthly, and seasonal values. The study revealed distinct patterns in benzene concentrations. Benzene levels were lowest during the early morning hours, specifically from 1:00 a.m.to 7:00 a.m.. Concentrations then increased from 7:00 a.m. to 9:00 a.m. and again from 4:00 p.m. to 11:00 p.m.,corresponding to the morning and evening peak traffic hours. However, between 10:00 a.m. and 4:00 p.m., the concentration decreased due to reduced traffic levels. These diurnal variations in benzene concentration are influenced by meteorological parameters. Comparing the two seasons, higher concentrations of Benzene, EthylBenzene, and MP-xylene were observed during the summer season. This increase is attributed to the elevated temperatures during summer, which promote the vaporization of BTEX compounds. Conversely, lower BTEX concentrations were recorded during the monsoon season due to the wet deposition process. The observed positive correlation(r > 0.5) among BTEX parameters strongly suggests a common source, most likely originating from vehicular emissions.展开更多
文摘The reported study examines the diurnal and seasonal variations of tropospheric ozone and its precursors in Bangalore,India,from January to December 2020,and explores the impact of meteorological parameters and the ventilation coefficient(VC)on ozone levels.Tropospheric ozone,a significant secondary pollutant,poses a major environmental and health challenge in urban areas.The study focuses on ozone,nitrogen oxides(NO and NO2),Sulphur dioxide(SO2),and carbon monoxide(CO),revealing that ozone peaks in the early afternoon due to solar radiation,while precursor pollutants show morning and evening peaks linked to traffic emissions.Higher ozone levels occur in winter(due to reduced boundary layer height)and summer(due to increased photochemical activity),while the monsoon period shows the lowest levels due to the washout effect.The VC values are generally higher during the day(587 m^(2)/s)compared to night(246 m^(2)/s),with the highest recorded in summer(1,935 m^(2)/s)and the lowest in the post-monsoon season(209 m^(2)/s).Higher VC enhances pollutant dispersion,while lower VC leads to accumulation.However,surface ozone concentrations increase with higher VC due to photochemical processes.The findings highlight the complex interplay of meteorology,emissions,and boundary layer dynamics,informing strategies for urban air quality management.
文摘In the urban atmosphere of Bengaluru, various volatile organic compounds(VOCs), particularly Benzene,Toluene, Ethylbenzene, and Xylene(BTEX), have shown an increasing trend in concentration. The present research was conducted during summer and monsoon seasons, focusing on Kadubeesanahalli, a high-traffic area within the Bengaluru Metropolitan City. Hourly sample data was collected using a BTEX analyzer(Model GC955-600) and subsequently transformed into daily, monthly, and seasonal values. The study revealed distinct patterns in benzene concentrations. Benzene levels were lowest during the early morning hours, specifically from 1:00 a.m.to 7:00 a.m.. Concentrations then increased from 7:00 a.m. to 9:00 a.m. and again from 4:00 p.m. to 11:00 p.m.,corresponding to the morning and evening peak traffic hours. However, between 10:00 a.m. and 4:00 p.m., the concentration decreased due to reduced traffic levels. These diurnal variations in benzene concentration are influenced by meteorological parameters. Comparing the two seasons, higher concentrations of Benzene, EthylBenzene, and MP-xylene were observed during the summer season. This increase is attributed to the elevated temperatures during summer, which promote the vaporization of BTEX compounds. Conversely, lower BTEX concentrations were recorded during the monsoon season due to the wet deposition process. The observed positive correlation(r > 0.5) among BTEX parameters strongly suggests a common source, most likely originating from vehicular emissions.
