Concentrations of surface O 3, NO 2 and CO during winter seasons at a semi-arid region - Agra, India

Indian Journal of Radio & Space Physics

Vol. 37, April 2008, pp. 121-130

Concentrations of surface O3, NO2 and CO during winter seasons at

a semi-arid region – Agra, India

Renuka Saini, G S Satsangi & Ajay Taneja

School of Chemical Sciences, Department of Chemistry, St. John’s College, Agra 282 002, India

(E-mail: [email protected])

Received 6 March 2006; revised 20 February 2008; accepted 22 February 2008

Surface measurements of O3 (ozone) and its precursor gases such as NO2 and CO have been made over an urban site of

Agra (semi-arid region). Ozone and NO2 show diurnal variations to an urban site during winter season. The overall increase

of ozone is attributed to the increase in NO2, CO and other precursor’s emissions by different sources in the proximity of

both the sites, i.e. St. John’s College (SJC) and Dayalbagh. The average concentration of ozone was found to be 27.3 ppbv

and it ranges from 1.2 to 69.0 ppbv, whereas the average concentration of NO2 and CO were 66.3 ± 7.0 ppbv and 710.3 ±

159.4 ppbv, respectively. The coefficient of determination of regression curve between O3 and NO2 were r = 0.50 at SJC and

r = 0.68 at Dayalbagh, whereas correlation between O3 and CO were r = 0.75 at SJC and r = 0.50 at Dayalbagh, indicating

positive correlation. Air samples from the two different locations of Agra city have indicated that the concentrations of

ozone and CO were within the permissible limits but NO2 concentration was above the limit.

Keywords: Ozone, Precursor gases, NO2, CO, Photochemical production, Semi-arid region

PACS No.: 92.60.Sz, 82.33.Tb

1 Introduction It is well recognized that ozone plays an important

role in absorbing the sun’s ultraviolet radiation. Now

the importance of ozone in the troposphere is also

known. It is one of the greenhouse gases absorbing

the outgoing long wave radiation at 9.6 µm. Air

pollution of high surface ozone arising from

photochemical formation and accumulation has

plagued many regions worldwide1,2

. In some of the

developed countries like UK and USA, the problem of

air pollution in urban areas has been successfully

dealt with, while in most developing countries like

China and India, the situation is rather serious due to

their poor economy and insufficient financial

investment for control of urban air pollution3. In the

presence of volatile organic compounds (VOC’s), CO

and nitrogen oxides (NO + NO2 = NOx), ozone is

photo chemically produced and can accumulate to

hazardous levels in favourable weather conditions4,5

.

The anthropogenic volatile organic carbon (VOCs)

emissions, which consist of non-methane

hydrocarbons (NMHC) has been the subject for

extensive control programme in many countries in

order to reduce ambient ozone concentration. Major

contributors to the concentration of upper

tropospheric NOx are lightning, aviation and NOx

emissions at the surface, which largely consist of

energy consumptions, soil emissions, vegetation and

biomass burning. Ozone production depends

nonlinearly on NOx concentration6. However, NO is

readily oxidized to NO2, which has considerable

biological significance. It irritates the alveoli of the

lungs, and the response of the human respiratory

system to short term exposure to NO2 also leads to

increased airway resistance and decreased pulmonary

diffusing capacity7.

Accurate characterization of ozone precursors,

mainly CO (from vehicular exhaust) is extremely

important for understanding tropospheric ozone

formation and accumulation, and crafting effective

control strategies to better address ozone air quality

management issues. Biomass burning in the tropics is

considered to significantly affect the regional and

global distribution of tropospheric ozone, because it

emits a large amount of trace gases such as CO2 and

CH4 as well as ozone precursor gases, NOx, CO and

hydrocarbons7,8

and these can affect distant areas

through long-range transport9-12

. Out of these, CO has

a relatively long lifetime in the atmosphere (between

about two weeks and two months)13

and thus may be

used as an important pollution tracer. The main goal

of measuring CO concentration is to evaluate the

dependency of ozone production upon CO, as it is

directly produced in the biomass burning process, and

can be measured with good precision and accuracy.

None of the other trace gases produced in biomass

INDIAN J RADIO & SPACE PHYS, APRIL 2008

122

burning, such as methane14

and CO2 have variations

as large as CO, thus making changes more difficult to

detect. In the present site, large portion of population

is depending on biomass burning for cooking and

warming houses during winter season. This activity

increases heat, which can also be used for bringing

respite from extreme cold conditions. Thus, increase

in intensity of regional emissions of these precursor

gases could potentially enhance surface ozone

concentrations. Economic projections indicate that

larger increase in emissions may occur over the next

50 years if current development persists. If these

occur, the impact of ozone on public health and

vegetation15-17

would be experienced in the near

future.

In India, few studies have reported ozone

concentrations in tropical rural coastal18

, urban areas19

and high altitude sites20

. This paper deals with the

study of concentration of O3, NO2 and CO at different

locations in Agra city during winter season, because

during winters there is frequent occurrence of fog and

clear sky. Foggy conditions help the pollutants to

settle down and the lifetime of ozone precursors

would be considerably greater in winters than in any

other season. Thus the study of ozone and its

precursor gases is an important subject not only for

understanding atmospheric chemistry but also for

environment and climate related studies. Pollutants

emitted from traffic and industrial activities play an

important role in the formation of ozone. Air

sampling of O3 measurements were designed to obtain

monthly ground level concentration of O3 and to see

the effects of vehicular pollution on O3 concentration.

However, the measurements of ozone and related

gases are very limited over the semi-arid Indian

regions. The growing industrial activities in this

region add to the importance of these studies.

2 Experimental method

2.1 Sampling site

Agra, the city of the Taj Mahal (27°10′N 78°02′E)

is located in the north central part of India, about 200

km south of Delhi in the Indian state of Uttar Pradesh.

A part of the great northern Indian plains, Agra city is

considered as a semi-arid zone as two-thirds of its

boundary is surrounded by the Thar desert of

Rajasthan. Three highways cross this city. Sampling

was carried out at two sites, St. John’s College (SJC)

and Dayalbagh. The first site was SJC, which is

situated in the heart of Agra city, is considered as the

high traffic density sampling site. It lies by the side of

a road that carries a maximum traffic density of about

10,000 (105) vehicles per day (Satsangi et al., 2004).

The second site Dayalbagh is situated in the northern

part of the city. It is devoted to agriculture, where

tube-well pumps are used for irrigation purposes, run

by diesel and has low density of residence. This is a

relatively cleaner site. Major urban activity centers,

i.e. the industrial area (Sikandra Phase 3) as well as

Mathura Refinery are situated in the north-west part

of the first sampling site (SJC) as shown in

Fig. 1, which include foundries, rubber processing

units, chemical industries, tanneries, ferrous and non-

ferrous metal casting and lime processing units. These

units emit major gaseous pollutants21

like CO, NOx

and SO2.

2.2 Sample collection and analysis

The present study was conducted during winter

seasons of years 2003-2005 (November, 2003 to

February, 2005). Agra has a tropical climate.

Summers (April-June) are extremely hot and

maximum temperature can be as high as 45°C while

winters (November to February) are foggy. Heavy

rains and humidity mark the monsoon season

(July-September). In October while the day

temperature remains as in September, the nights

become cooler. From November both day and night

temperature steadily drops and in January, the coldest

month, the mean daily temperature is 10°C and the

mean daily minimum temperature is 6°C. The relative

humidity during the winter months ranges between 60

and 70%. The downward wind is SSE 29% and NE

6% in summers and it is W-NW 9.4% and NNW

11.8% in winters.

Neutral KI buffer method (a chemical method) was

used to measure the air concentration of O3. Surface

O3 and NO2 were collected with the help of a handy

sampler (KDM Instruments, New Delhi). For O3 air

was drawn in impingers containing absorbing solution

of O3 (KH2PO4, Na2HPO4 and KI). Air was drawn for

2 h at a rate of 2 LPM in the KI buffer solution

(pH 7.0 absorbing solution). The liberated iodine,

which forms the triiodide ion, was measured

calorimetrically at 352 nm using UV-VIS

spectrophotometer22

(Heλios-α, Thermospectronic,

UK). During all the winter months, samples were

collected throughout the week with an average of 4-5

samples per day. Total number of 220 samples was

collected during the study. Some samples (14-17)

were collected to see diurnal variation for a particular

time interval. Impingers were shielded from direct

sunlight by covering them with black sheet to avoid

SAINI et al.: SURFACE O3, NO2 & CO DURING WINTER AT AGRA, INDIA

123

photodecomposition. Low temperature was

maintained by putting ice in the box, in which

impingers were kept. Ozone was immediately

analyzed after sampling. Incomplete samples were

discarded whenever there was power failure during

sample collection. Quality assurance parameters like

collection efficiency and reproducibility were

measured. To determine collection efficiency,

samples of air in three different impingers in a series

were taken and the concentration of O3 in each

determined separately. Maximum concentration was

found in the first impinger. Two parallel sets of

measurements were carried out to determine the

reproducibility with identical absorbing solution. The

differences of the parallel measurements under

ambient condition were less than 6%.

The constituent NO2 was also measured by the

impinger technique. Air was drawn in to 20-ml. of

sodium arsenite solution at a flow rate of 2 LPM for

2 h. Concentration of NO2 was estimated by the

Saltzman’s method as modified by Jacob and

Hoccheiscer22

. The NO2 (as NO2-) concentration was

detected colorimetrically on reaction with phosphoric

acid, sulphanilamide and n-Naphthylamine diamine

dihydrochloride (NEDA), producing an azo dye. The

absorbance of the colour was read at 540 nm using

UV-VIS spectrophotometer (Heλios-α, Thermo-

spectronic, UK). To determine collection efficiency

same technique as for O3 was used. Maximum

concentration was found in the first impinger. Two

parallel sets of measurements were carried out to

determine the reproducibility with identical absorbing

solution. The differences of the parallel measurements

under ambient condition were less than 4%.

Concentration of CO was measured by a portable

YES-205 multi-gas monitor (Young Environment

System Inc 140-8771 Douglas St. Richmond, B.C.

V6X1V2, Canada). The monitor measures CO in the

interval of 0-50 ppm with a resolution of 0.3 ppm.

Zero and span were checked at regular intervals using

zero air and standard of CO. For CO measurements,

the instrument was positioned 2 m above the ground

level. While measuring CO, temperature and relative

humidity were also measured.

Fig. 1 — Map of Agra city


124

3 Results and discussion The average concentrations of O3, NO2 and CO for

both the sites, for all the months of winter season are

presented in Table 1. The average concentrations of

O3, NO2 and CO were 34.6 ± 5.4 ppb, 56.2 ± 21.7 ppb

and 1088 ± 202.75 ppb at SJC and 20.1 ± 5.9 ppb,

27.4 ± 19.6 ppb and 332.5 ± 116 ppb at Dayalbagh,

respectively. Maximum O3, NO2 and CO

concentrations were found to be 69.0 ppb, 150.7 ppb

and 1130 ppb respectively, at SJC, whereas minimum

O3, NO2 and CO concentrations were found to be

1.2 ppb, 2.1 ppb and 269 ppb at Dayalbagh. It is clear

that the concentrations of these gases are higher at

SJC as compared to Dayalbagh. Higher pollution at

SJC is attributed to diesel/petrol vehicular emissions,

as the major source of pollution.

Figure 2(a) shows the difference in diurnal

variation of O3 averaged over the period from

November 2003 to February 2005. At Agra highest

mixing ratio of O3 in the winter season is observed to

be 59.6 ppb during peak noontime and the lowest of

13.7 ppb appears during early morning. In January,

high variation could be attributed to daily variation in

weather conditions (frequent occurrence of fog and

clear sky). Foggy condition would result in low

photochemical formation. The O3 levels are observed

to be low during nighttime; as there is no photo-

oxidation of precursors (causing O3 production). Low

levels of O3 during early morning and nighttime are

due to combined effects of chemical loss by NO and

NO2 species and suppressed boundary layer mixing

processes (due to low temperature). Moreover, during

nighttime the titration of O3 by surface emission of

NO in shallow boundary layer and loss due to surface

deposition continues. Boundary layer processes and

meteorological parameters also play important role in

the O3 variabilities25

(Y N Ahammed, 2006). Increase

in O3 during the day is basically due to photo-

oxidation of precursor gases like CO, CH4 and

hydrocarbons in the presence of sufficient amount of

NOx.

Diurnal variation of ozone gives a clear picture of

ozone status in Agra region. During the day, ozone

concentration starts increasing gradually after sunrise,

attains maximum value during noontime and then

decreases. As evident from the figure the rate of

increase in O3 concentration during morning is fast,

whereas in the evening it decreases rather slowly.

During the day-time, peak O3 concentrations also

coincide with flux of solar radiation, indicating its

photochemical production. Low concentration of O3

during night/early morning time could also be a result

of its deposition and surface chemical reactions. Thus,

NO emitted from vehicular emissions serves as a

Table 1 — Threshold limit for air borne contaminates

Pollutants Time Weighted Average, ppb

O3a 50.3 (8 h)

NO2b 30 (Annual)*

40 (24 h)**

COb 1,750 (8 h)

3,492.8 (1 h)

*Annual Arithmetic mean of minimum 104 measurements in a

year taken twice a week 24 hourly at uniform interval.

**24 hourly/8 hourly values should be met 98% of the time in

a year. However, 2% of the time it may exceed but not on two

consecutive days.

Source: aWHO air quality guidelines 2005

(http://www.euro.who.int/document/E87950.pdf) bWBA,CPCB, 2003

[

Fig. 2 — Difference in diurnal variation of: (a) O3, (b) NO2 and

(c) CO at St. John’s College and Dayalbagh


125

nighttime/morning sink. Besides automotive

emission, NO has also been suggested to be emitted

from soil; emissions depend upon soil temperature

and soil humidity11,22

(Kirchhoff, 1988; Satsangi et al,

2004). Further changes in the boundary layer height,

as well as in the incoming solar radiation, are quite

rapid during morning time, and therefore the

maximum changes in O3 are observed during this

time27

(Naja and Lal, 2002).

Table 2 compares the concentrations of O3 at

present site with similar work done in other sites of

India, i.e. Ahmedabad19

, Mt. Abu20

and Gadanki23

. It

is evident from these results that concentration of O3

in the present site was within the range of urban

(Ahmedabad) and high altitude areas (Mt.Abu,

Gadanki). The daytime increase in ozone

concentration, which is a pronounced feature of a

polluted site, it is basically due to the photo-oxidation

of the precursor gases such as CO, CH4 and NMHC in

the presence of sufficient amount of NOx. The

well-known photo-oxidation cycle of CO can be

represented as28

(Pitts and Pitts, 1998)

CO + OH → CO2,

H + O2 + M → HO2 + M,

HO2 + NO → NO2 + OH,

NO2 + hv → O (3P) + NO,

λ < 420 nm

O (3P) + O2 + M → O3 + M,

Net: CO + 2O2 + hv → CO2 + O3

In this process NOx acts as a catalyst and continues

to do so until physical processes permanently remove

it or it gets transformed to other oxides of nitrogen.

Similar ozone productive cycles take place for CH4

and NMHC’s, but their O3 yield is much higher than

that of CO. Production of O3 from its precursor, NOx

is one of the important features of the polluted

atmosphere. In the troposphere, peroxy radicals that react rapidly with NO mainly play this role.

The main sources of O3 precursors are vehicular

traffic, which significantly emit the oxide of nitrogen

and CO. The increase in number of vehicles is

associated with higher concentrations of NO2 and CO,

which have also increased. Concentration of NO2 and

CO attains higher levels during winter season as they

get transported through northwesterly wind flow from

the polluted regions. Also in winter months, the

pollutants emitted from various anthropogenic and

natural sources, are trapped in the boundary layer due to frequent temperature inversions.

Tropospheric O3 is also produced from the NOx

catalyzed oxidation of various hydrocarbons24,25

.

Figure 2(b) shows the diurnal variation of NO2

averaged at both sites during winter months. The

average concentration of NO2 at SJC and Dayalbagh

were 41.7 ± 8.7 ppb and 26.4 ± 3.2 ppb, respectively

and the range was 5.0-187.4 ppb at SJC while

2.1-111.1 ppb at Dayalbagh. Figure 2(c) shows the

diurnal variation of CO at both the sampling sites

during the study period (November 2003-February

2005). At SJC average concentration of CO was

1088 ± 202.7 ppb and for Dayalbagh it was 332.5 ±

116 ppb while it varied in the range 269-1130 ppb.

To see the effects of NO2 and CO on O3 production

the concentrations of these gases at both sites were

compared (Fig. 3). The concentrations of O3, NO2 and

CO at Dayalbagh were in the ranges 11.8-37.5 ppb,

5.2-187.4 ppb and 147-324 ppb, respectively; while at

SJC these are 13.7-59.6 ppb, 13.7-49.1 ppb and

188-1358 ppb, respectively. The concentrations of

NO2 and CO are greater at SJC than at Dayalbagh,

probably because SJC is located near the main road,

which is a source of these precursor gases. Linear

regression lines are drawn to estimate the associations between O3 and NO2 concentrations at both sites.

The O3-NO2 correlation graph [Fig. 4(a)] depicts

that the regression (r = 0.50) at SJC, i.e. the efficiency

of O3 production per mol of NO2 was 50%, as this

area is polluted by commercial and heavily vehicles,

where CO is (the other dominant precursors of O3)

present in sufficient amount, which contributes in O3

Table 2 — O3 concentration (ppb) in different cities of India

compiled from literature data

Study area Month Average

concentration

± s.d.

Reference

November 51.4±10.9

December 46.9±13.8

January 40.2±12.6

Ahemdabad

February 34.2±15.9

Lal et al, 2000

[Ref. 19]

November 26.1±14.1

December 30.0±15.0

January 26.2±13.5

Gadanki

February 30.1±16.5

Naja et al, 2002

[Ref. 23]

November 48.8±7.7

December 44.4±9.0

January 46.2±9.5

Mt. Abu

February 46.7 ±10.9

Naja et al, 2003

[Ref. 20]

November 28.5± 4.2

December 31.1± 7.3

January 20.4± 7.4

Agra

February 24.5± 3.9

Present Study

[


126

production. Whereas, Fig. 4(b) suggests that at

Dayalbagh, the regression (r = 0.68) showing that the

efficiency of O3 production per mol of NO2 was 68%,

as this is a residential area dominated by agricultural

activities. Similarly, the O3-CO correlation graph

[Fig. 5(a)] shows regression (r = 0.75) at SJC,

indicating that the efficiency of O3 production per mol

of NO2 was 75%, as the concentration of CO usually

remain constant because of daily routine of traffic

(same routine is nearly followed by all the vehicles

due to specific timings for school, college and offices

in the morning and evening). At Dayalbagh,

regression (r = 0.50), illustrating that the efficiency of

O3 production per mol of NO2 was 50% at this site.

This correlation values are in an air mass where O3

production has just occurred.

Table 3 provides a comparison of correlation

coefficient and slope with the other observations

made in different sites of Asia. Slope between ozone

and CO provides the information on ozone production

per molecules of CO. Correlation between

concentrations of O3 and CO give ozone production

efficiency (slope 0.076), which is similar to those of

other studies over the Asian region. Lower ozone

production efficiency and lower correlations are

indications of incomplete photochemical processes

over the Asian region. It has been studied that

biomass burning and fossil fuel burning emissions

occur simultaneously over Asian region unlike North

America and Europe31

(Reiner et al, 2001) and carbon

to NOx emission ratio is much higher over Asia than

over North America32

(Lelieveld et al., 2001).

Calculated intercept and slope in O3 and CO at the

present site is 1.97 and 0.076, respectively, with

correlation coefficient of 0.40. Lower slope and

relatively lower correlation between ozone and CO

may be the indicators of incomplete photochemical

processes26

. The present results are consistent with the

studies made over the Asian region20,27,28

, which also

show lower values of slopes and intercept. This result

further supported the lower ozone production

efficiency, which earlier the present authors compared

with that of Ahmedabad, Mt. Abu and Gadanki.

Fig. 4 — Correlation of O3 and NO2 at (a) St.John’s College

(r = 0.50, p = 0.004, n = 40) and (b) Dayalbagh (r = 0.68,

p = 0.07, n = 40)

Fig. 3 — Diurnal Variation of O3, NO2 and CO at

(a) St. John’s College and (b) Dayalbagh


127

Table 4 shows the permissible limits of

concentration of O3, NO2 and CO. Present data of O3

and CO were compared with permissible limits of

respective species and found to be within the range.

So it is believed that there is no harmful effect of

Fig. 5 — Correlation of O3 and CO at (a) St. John’s College

(r = 0.75, p = 0.004, n = 40) and (b) Dayalbagh (r = 0.50,

p = 0.07, n = 40)

these gases in the climate of this region, but

concentration of NO2 is alarming and crossed the

permissible limits. This was further confirmed by the

earlier study, which calculates the exposure index of

O3, i.e. AOT 40. Calculated results suggested that the

present O3 exposures are lower than the critical level

of O3 and the present level of O3 does not pose

harmful impact on vegetation29

. Although the present

level of O3 exposures are lower than the critical level

of O3, immediate implementation of effective control

technologies for reducing emissions of O3 precursors

is suggested.

One of the primary factors influencing

photochemical formation is the intensity of solar

radiation. Other parameters that influence the

concentration of O3 are the temperature, humidity,

wind direction and wind speed and levels of

pollutants. Figure 6 shows the correlation between O3

with meteorological parameters. There is good

correlation of O3 with solar radiation and temperature

(r = 0.63; p = 0.01 and r = 0.75; p = 0.001), which is

followed by very poor correlation with relative

humidity (r = 0.01, p = 0.001). High concentrations of

O3 are therefore likely to occur with high temperature

and solar radiation and low relative humidity. The

effect of air transport has been examined by the wind

study of the winter season. The prevailing winds were

WNW and NNW. The levels of O3 were found to be

higher during winds from WNW and NNW. This is

supported by the fact that the major urban activity

centers are situated at NW direction of the sampling

sites. These units emit significant amount of NO2 and

other gases. Winds from WNN and WNW directions

probably transport air at the sampling sites. The

precursors produce O3 photo-chemically during the

transportation time.

Table 3 — Ozone and CO correlations details from different sites of world compiled from literature data

Site Ozone, ppb CO, ppb Slope Corr. Coeff. References

Sable Island 33.3 114 0.3 0.68 Chin et al. 30

Parrish et al. 26

Seal Island 38.9 129 0.31 0.74 Chin et al. .30

Parrish et al. 26

Cape Race 30.3 124 0.33 0.47 Chin et al.30

Parrish et al. 26

Bermuda 11-65 65-255 0.27 0.65 Dickerson et al. 31

Oki 29.2-55.0 105-248 0.006-0.23 0.18-0.66 Pochanart et al. 27

Mt Fuji 24.8-59.8 92.4-158.6 0.09-0.19 0.41-0.50 Tsutsumi & Matsueda28

Mt Abu 30.1 ± 12.8 154.6 ± 73.3 0.13 ± 0.01 0.52 Naja et al. 20

Agra 26.1 ± 5.7 710.2 ± 159.3 0.076 0.40 Present Study


128

Fig. 6 — Correlation between (a) peak noontime O3 and solar

radiation (r = 0.62, n = 13), (b) O3 and temperature (r = 0.75, n =

25) and (c) O3 and solar relative humidity (r = 0.01, n = 27)

4 Conclusions It is well known that ozone-forming capacity in the atmosphere is highly dependent on the amount of NO2, CO and other precursors, which are closely related to traffic. Out of the two sites in the present study, SJC which is situated near a busy road is considered as a heavy vehicular traffic area, whereas Dayalbagh is areas covered partly by agriculture and relatively clean residential area. The results indicate higher concentrations of O3, NO2 and CO at SJC compare to the values observed at Dayalbagh. This shows that high concentration of O3 at SJC is due to higher abundance of precursors, i.e. NO2 and CO. The present study also demonstrate that O3 shows a strong diurnal variation with maximum value of 69 ppb at peak noontime, due to the photochemical production, while minimum value of 2.1 ppb was observed at early morning time, as there is no photo-oxidation of precursors. Mixing ratios of O3 decreases more slowly during the evening than they increase during the morning. This has been attributed to slower titration of O3 by NO during the late evening times. Lower slope and relatively lower correlation between O3 and CO may be the indicators of incomplete photochemical processes.

Acknowledgements The authors would like to thank the Principal, Dr. F

M Prasad and the HOD, Dr. Ashok Kumar, SJC, Agra

for providing them the necessary facilities. One of the

authors (GSS) also wishes to acknowledge the award

of Research Associateship from CSIR, New Delhi for

this study.

Table 4 — Maximum, minimum, mean and standard deviation values of concentration (all in ppb) of O3, NO2 and CO at

St. John’s College and Dayalbagh at Agra during winters of 2003-2005

St. John’s College Dayalbagh

Nov. Dec. Jan. Feb. Nov. Dec. Jan. Feb.

O3

Mean 35.7 41.7 28.7 32.6 21.4 20.5 12.1 26.4

S.d. 3.9 8.7 11.8 4.6 4.6 6.0 3.0 3.2

Max. 65.5 76.2 68.0 63.6 28.3 37.3 29.7 27.4

Min. 6.4 9.7 7.7 3.9 3.1 2.4 1.4 1.2

NO2

Mean 40.0 84.7 61.7 38.4 7.1 51.4 34.7 16.7

S.d. 4.1 13.8 15.2 6.2 1.1 5.3 6.6 2.6

Max. 118.1 187.4 129.5 168.0 50.7 104.0 82.4 111.1

Min. 7.0 7.5 8.2 5.0 5.0 6.9 4.6 2.1

CO

Mean 1130 1126 975 1121 269 384 390 287

S.d. 120 129 397 165 96 97 182 89

Max. 1295 1261 1101 1279 381 486 502 393

Min. 876 812 784 889 112 126 245 119


129

References 1 Greenfelt P & Schjoldanger J, Photochemical oxidant in the

troposphere: a mountain menace, Ambio (Sweden), 13 (1984)

61.

2 Volz A & Kley D, Evalution of the Montsouris series of

ozone measurements made in nineteenth century, Nature

(UK), 332 (1988) 240.

3 Zhang L, Chen C & Murlis J, Study on winter air pollution

control in Lanzhou, China (MIT Press, UK), (2000) 351.

4 Davidson A, Update on ozone trend in California’s south

coast air basin, J Air Waste Manage Assoc (USA), 43 (1993)

226.

5 Wakamatsu S, Ohara T & Uno I, Recent trends in precursor

concentrations and oxidant distribution in the Tokyo and

Osaka areas, J Atmos Chem (Netherlands), 30 (1996) 715.

6 Lin X, Trainer M & Liu S C, On the non-linearity of the

tropospheric ozone production, J Geophys Res (USA), 93

(1988) 15879.

7 Mudgal R, Sharma B, Upadhyay R & Taneja A, Seasonal

variation of ambient air quality at selected sites in Agra city,

Indian J Radio Space Phys, 29 (2000) 127.

8 Curtzen P J, Detany A C, Greenberg J, Haagenson P, Heidt

L, Lueb R, Pollock W, Seiler W, Wartburg A, Zimmerman P,

Tropospheric chemical composition measurements in Brazil

during the dry season, J Atmos Chem (Netherlands), 2 (1985)

233.

9 Curtzen P J & Andreae M O, Biomass burning in the tropics:

impact on atmospheric chemistry and biogeochemical cycles,

Science (USA), 250 (1990) 1669.

10 Andreae M O, Soot carbon and excess fine potassium: long-

range transport of combustion-derived aerosols, Science

(USA), 220 (1983) 1148.

11 Kirchhoff V W J H & Nobre C A, Atmospheric chemistry

research in Brazil: Ozone measurements at Natal, Manaus

and Cuiaba, Rev Bras Geofis (Brazil), 24 (1986) 95.

12 Reichle H G, Connors V S, Holland J A, Hypes W D, Wallio

H A, Casas J C, Gomsen B B, Saylor M S & Hesketh W D,

Middle and upper Tropospheric carbon monoxide mixing

ratios as measured by a satellite borne remote sensor during

November 1981, J Geophys Res (USA), 91 (1986) 10865.

13 Fishman J, Watson C E, Larsen J C & Logan J A,

Distribution of tropospheric ozone determined from satellite

data, J Geophys Res (USA), 95 (1990) 3399.

14 Novelli P C, Masarie K A & Lang P M, Distributions and

recent changes of carbon monoxide in the lower troposphere,

J Geophys Res (USA), 103 (1998) 19015.

15 Alvala P C & Kirchhoff V W J H, Observations of

atmospheric methane and monoxide in Brazil: SCAR B

mission, J Geophys Res (USA), 103 (1998) 32101.

16 Pochanart P, Akimoto H, Kinjo Y & Tanimoto H, Surface

ozone at four remote sites and the preliminary assessment of

the exceedences of its critical level in Japan, J Atmos Chem

(Netherlands), 36 (2002) 4235.

17 Lefohn A S, Jackson W, Shadwick D S & Knudesen H P,

Effect of surface ozone exposure on vegetation grown in the

southern Appalachian mountains; identification of possible

areas of concern, Atmos Environ (UK), 11 (1997) 1695.

18 Mauzerall D L & Wang X, Protecting agricultural crops from

the effects of tropospheric ozone exposure: reconciling

science and standard setting in the United States, Europe and

Asia, Ann Rev Energy Environ (Japan), 26 (2001) 237.

19 Debaje S B, Jeyakumar S J, Ganeshan K, Jadhav D B &

Seetaramayya, Surface ozone measurements at tropical rural

coastal station Tranquebar, India, Atmos Environ (UK), 37

(2003) 4911.

20 Lal S, Naja M & Subbaraya B H, Seasonal variations in

surface ozone and its precursors over an urban site in India,

Atmos Environ (UK), 34 (2000) 713.

21 Naja M, Lal S & Chand D, Diurnal and seasonal variabilities

in surface ozone at a high altitude site Mt. Abu (24.6°N,

72.7°E, 1680 m asl) in India, Atmos Environ (UK), 37 (2003)

4205.

22 Satsangi G S, Lakhani A, Kulshrestha P R & Taneja A,

Seasonal and diurnal variation of surface ozone and a

preliminary analysis of exceedence of its critical levels at a

semi-arid site in India, J Atmos Chem (Netherlands), 47

(2004) 271.

23 National Environmental Engineering Research Institute

(NEERI) Nagpur, Ministry of Environment & Forest, New

Delhi, 1993.

24 Harrison R M, Secondary Pollutants in Handbook of Air

Pollution Analysis, edited by R M Harrison and R Perry

(Chapman and Hall, New York, USA), 1986.

25 Ahammed Y N, Reddy R R, Gopal K R, Narasimhulu K,

Basha D B, Reddy L S S & Rao T V R, Seasonal variation of

surface O3 and its precursor gases during 2001-2003,

measured at Anantapur (14.62°N), a semi-arid site in India,

Atmos Res (Netherlands), 80 (2006) 151.

26 Kirchhoff V W J H & Rasmussen R A, Time variations of

CO and O3 concentrations in a region subject to biomass

burning, J Geophys Res (USA), 95 (1990) 7521.

27 Naja M & Lal S, Surface ozone and precursor gases at

Gadanki (13.5°N, 79.2°E), a tropical rural site in India, J

Geophys Res (USA), 107 (2002) 8.

28 Pitts Finlayson B J & Pitts J N, Atmospheric Chemistry:

Fundamentals and Experimental Techniques, (John Wiley,

New York), 1998.

29 Rowland F S, Stratospheric ozone depletion by

chlorofluorocarbons, Ambio (Sweden), 19 (1990) 281.

30 Cahoon Jr., D R, Stockes B J, Levines J S, Cofer III W R &

O’Neill K P, Seasonal distribution of African savannah fires,

Nature (UK), 359 (1992) 812.

31 Reiner T, Sprung D, Jost C, Andreae M O & Shetter R E,

Chemical characterization of pollution layers over the

tropical Indian ocean: signature of emission from biomass

and fossil fuel burning, J Geophys Res (USA), 106 (2001)

28497.

32 Lelieveld J, The Indian ocean experiment: widespread air

pollution from South and Southeast Asia, Science (USA), 291

(2001) 1031.

33 Parrish D D, Trainer M, Williams, E. J., Fahey, D.W.,

Hubler, G., Liu, S.C. and Fehsenfeld F C, Measurements of

the NOx-O3 photostationary state at Niiwot Ridge, Colorado,

J Geophys Res (USA), 91 (1986) 5361.

34 Pochanart P, Hirokawa J, Kajii Y, Akimoto H & Nakao M,

The influence of regional scale anthropogenic activity in

Northeast Asia on seasonal variations of surface ozone and

carbon monoxide observed at Oki, Japan, J Geophys Res

(USA), 104 (1999) 3621.

35 Tsutsumi Y & Matsueda H, Relationship of ozone and CO at

the summit of Mt. Fuji (35.35°N, 138.73°E, 3776m above

sea level) in summer 1997, Atmos Environ (UK), 34 (2000)

553.


130

36 Chin M, Jacob D J, Munger L W, Parrish D D & Doddridge

B G, Relationship of ozone and carbon monoxide over North

America, J Geophys Res (USA), 99 (1994) 14565.

37 Dickerson R R, Doddridge B G, Kelley P & Rhoads K O,

Large-scale pollution of the atmosphere over the remote

Atlantic ocean: evidence from Bermuda, J Geophys Res

(USA), 100 (1995) 8945.

38 WHO air quality guidelines 2005 (http://www.euro.who.int/

document/E87950.pdf).

39 WBACPCB (World Bank Aided Central Pollution Control

Board), Sponsored Training Course on Air Pollution

Meteorology and Air Quality Modeling June 9-13, IIT

Kanpur, India, 2003.

40 Lawrence A J, Masih A & Taneja A, Indoor/outdoor

relationships of CO and oxides of nitrogen in domestic

homes with roadside, urban and rural location in central

Indian region, Indoor Air (Denmark), 15 (2004) 76.

Concentrations of surface O 3, NO 2 and CO during winter seasons at a semi-arid region - Agra, India

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Transcript of Concentrations of surface O 3, NO 2 and CO during winter seasons at a semi-arid region - Agra, India