Seasonal variations in surface ozone and its precursors over an urban site in India

Lal, Shyam; Naja, Manish; Subbaraya, B. H.

doi:10.1016/s1352-2310(99)00510-5

Cited by 290 publications

(171 citation statements)

References 26 publications

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“…The increase of ozone in the troposphere is the result of increase in human produced ozone precursor emissions. Ozone concentrations are found to be increasing in the free troposphere as well as near the surface in many parts of the northern hemisphere Lal et al, 2000;Varotsos et al 1994;Nair et al 2002;Debaje and Kakade 2006). Table 1 shows the average surface-ozone concentration rate of change in the daytime (08:00-20:00 hours) and nighttime (20:00-08:00 hours) at Anantapur for the study period.…”

Section: Diurnal and Seasonal Variations Of Surface Ozonementioning

confidence: 99%

“…These are reformed for 15 min each on a daily basis for an initial period of 1 year and then once very 3-4 weeks afterward. The minimum detection limit of the analyzer is about 1 ppbv and its response is about 10 s. Lal et al (1998Lal et al ( , 2000 and Nair et al (2002) have also been employed the same O 3 analyzer described above in their study. The absolute accuracy of these types of system is reported to be 5% (Kleinman et al 1994).…”

Section: Experimental Techniquementioning

confidence: 99%

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Measurements of surface ozone at semi-arid site Anantapur (14.62°N, 77.65°E, 331 m asl) in India

et al. 2008

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In the present study, an attempt has been made to examine the governing photochemical processes of surface ozone (O 3 ) formation in rural site. For this purpose, measurements of surface ozone and selected meteorological parameters have been made at Anantapur (14.62°N, 77.65°E, 331 m asl), a semi-arid zone in India from January 2002 to December 2003. The annual average diurnal variation of O 3 shows maximum concentration 46 ppbv at noon and minimum 25 ppbv in the morning with 1σ standard deviation. The average seasonal variation of ozone mixing ratios are observed to be maximum (about 60 ppbv) during summer and minimum (about 22 ppbv) in the monsoon period. The monthly daytime and nighttime average surface ozone concentration shows a maximum (55±7 ppbv; 37±7.3 ppbv) in March and minimum (28±3.4 ppbv; 22±2.3 ppbv) in August during the study period. The monthly average high (low) O 3 48.9±7.7 ppbv (26.2± 3.5 ppbv) observed at noon in March (August) is due to the possible increase in precursor gas concentration by anthropogenic activity and the influence of meteorological parameters. The rate of increase of surface ozone is high (1.52 ppbv/h) in March and lower (0.40 ppbv/h) in July. The average rate of increase of O 3 from midnight to midday is 1 ppbv/h. Surface temperature is highest (43-44°C) during March and April months leading to higher photochemical production. On the other hand, relative humidity, which is higher during the rainy season, shows negative correlation with temperature and ozone mixing ratio. It can be seen that among the two parameters are measured, correlation of surface ozone with wind speed is better (R 2 =0.84) in compare with relative humidity (R 2 =0.66).

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Section: Diurnal and Seasonal Variations Of Surface Ozonementioning

confidence: 99%

Section: Experimental Techniquementioning

confidence: 99%

Measurements of surface ozone at semi-arid site Anantapur (14.62°N, 77.65°E, 331 m asl) in India

et al. 2008

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“…No long-run records of either surface ozone or ozone precursor concentrations exist for India, but global background levels of tropospheric ozone are increasing in general (37), and several site-specific measurements in India corroborate this trend (38,39). Emissions of all ozone precursors are rising in India, with NOx emissions outpacing NMVOCs; the ratio of these two precursors varies dramatically across the country (Fig.…”

Section: Ozonementioning

confidence: 99%

Recent climate and air pollution impacts on Indian agriculture

Burney

Ramanathan

2014

Proc. Natl. Acad. Sci. U.S.A.

266

152

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Recent research on the agricultural impacts of climate change has primarily focused on the roles of temperature and precipitation. These studies show that India has already been negatively affected by recent climate trends. However, anthropogenic climate changes are a result of both global emissions of long-lived greenhouse gases (LLGHGs) and other short-lived climate pollutants (SLCPs). Two potent SLCPs, tropospheric ozone and black carbon, have direct effects on crop yields beyond their indirect effects through climate; emissions of black carbon and ozone precursors have risen dramatically in India over the past three decades. Here, to our knowledge for the first time, we present results of the combined effects of climate change and the direct effects of SLCPs on wheat and rice yields in India from 1980 to 2010. Our statistical model suggests that, averaged over India, yields in 2010 were up to 36% lower for wheat than they otherwise would have been, absent climate and pollutant emissions trends, with some densely populated states experiencing 50% relative yield losses. [Our point estimates for rice (−20%) are similarly large, but not statistically significant.] Upper-bound estimates suggest that an overwhelming fraction (90%) of these losses is due to the direct effects of SLCPs. Gains from addressing regional air pollution could thus counter expected future yield losses resulting from direct climate change effects of LLGHGs.climate impacts | ozone | aerosols | agriculture | India

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“…Daytime increase in O 3 concentrations is a pronounced feature of urban polluted site, because of the photochemical oxidation of precursors such as CO, and VOCs in presence of sufficient NO x . Hyderabad being an urban location, NO x concentrations are commonly observed above the threshold level (* 10 pptv) which is conducive for O 3 formation (Lal et al 2000). However, NO x in the form of NO 2 produces O 3 by photolysis during sunlit hours, and NO in NO x reduces O 3 during night time.…”

Section: Temporal Study Of Trace Gasesmentioning

confidence: 99%

“…Thereafter, O 3 concentration increased and reached to a peak value in the afternoon. Daytime change in O 3 level depends on the intensity of solar flux and boundary layer height (Lal et al 2000). Increase in boundary layer height in the afternoon due to convective heating and consequent stratification, leads to the mixing of air in the lower altitude with the air in higher altitude rich in ozone concentration.…”

Section: Temporal Study Of Trace Gasesmentioning

confidence: 99%

Environmental monitoring of surface ozone and other trace gases over different time scales: chemistry, transport and modeling

Venkanna

Nikhil

Rao

et al. 2014

Int. J. Environ. Sci. Technol.

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Increasing concentration of tropospheric ozone (O 3 ) is a serious air pollution problem faced commonly by the urban people. The present study emphasizes on variations of air pollutant concentrations viz., O 3 , nitrogen oxides (NO x ), carbon monoxide (CO), sulfur dioxide (SO 2 ) and black carbon (BC) at a tropical urban site located in the Deccan plateau region with semi-arid climate. The air monitoring site revealed typical diurnal/seasonal trends attributing to the complex chemistry of surface O 3 formation from its precursors. Role of SO 2 in the formation of free radical (HO Á 2 ) and its impact on O 3 concentration is distinguished part of the study. The results showed the highest mean O 3 in summer (57.5 ± 15.2 ppbv) followed by winter and monsoon. Observations of BC aerosols showed the highest mean value during winter (8.2 ± 2 lg m -3 ) and the lowest in monsoon (4.2 ± 1 lg m -3 ). Besides local influences, long-range transport of air masses were also studied by simulating back trajectories at different elevations during the study period. Furthermore, statistical analysis and modeling was performed with both linear (regression) and nonlinear (neural network) methods.

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Seasonal variations in surface ozone and its precursors over an urban site in India

Cited by 290 publications

References 26 publications

Measurements of surface ozone at semi-arid site Anantapur (14.62°N, 77.65°E, 331 m asl) in India

Measurements of surface ozone at semi-arid site Anantapur (14.62°N, 77.65°E, 331 m asl) in India

Recent climate and air pollution impacts on Indian agriculture

Environmental monitoring of surface ozone and other trace gases over different time scales: chemistry, transport and modeling

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