Transcript Slide 1

Detection of NO2 Emission Hotspots, Trend and Seasonal
Variation over Indian Subcontinent Using TEMIS
tropospheric column NO2
Sachin D. Ghude
&
Suvarna Fadnavis, Yogesh K. Tiwari, G. Beig, Suraj Polade
Indian Institute of Tropical Meteorology, Pashan, Pune 411008 (INDIA)
In this study we focus on TEMIS tropospheric column NO2 retrievals from the
GOME and SCIAMACHY satellite spectrometer over Indian Sub-continent for the
period 1996-2006.
This data is obtained from the website:
http://www.temis.nl/airpollution/no2.html
GOME (ERS-2):
1996 – 2003
(0.25o * 0.25o, 1*e1013 Molecules/cm2)
SCIAMACHY (ENVISAT): 2003 – 2006
(0.25o * 0.25o, 1*e1013 Molecules/cm2)
(Version 1.1)
Objective:
1.
2.
3.
4.
5.
Identify the major NO2 emission hotspots
Quantify the trend over major Industrial zone
Identify the largest contributing regions
Seasonal Variation
Comparison with in situ surface observation
India is second to China for various emission and energy consumption in the Asia
region.
India has large variability in regional distribution of population and energy
consumption patterns.
Over the past two decades rapid industrialization, urbanization and traffic growth
due to economical development in India have believe to responsible for
increasing emissions of gaseous pollutants in this region.
The varying sectoral growth rates, consumption patterns and resource
endowments in India have led to widely different regional and sectoral emission
distribution.
This variability is further creating pockets of heavy pollutant emitting regions like
major industrial zones and metro-cities which has rapid rise in the vehicles
number in the last decade.
Many thermal power plants have become operational in last two decades, which
are consuming coal for electricity generation. Many large power plants have
inefficient operations without advanced emission controls resulting in excessive
emissions.
Therefore, a need arises for the policy makers to specially identify these regions
of high pollution and target the sectors for mitigation, which are causing it.
Sectors and sub-sectors for major emissions over India:
The regional distributions for NO2 LPS (large Point Source)
corresponds to coal and petroleum consumption pattern for India.
emissions
Coal contributes 45 % of total NOx emission in India while, transport contributes
32% of NOx emission which mostly consist of small and dispersed sources.
The contribution of biomass burning to NOx production is less over the India
which contributes 10-20% during March to May.
Electric power sector is the dominant component of Indian energy sector.
In India, coal is the primary fuel in thermal power plants, and gasoline and diesel
are the primary fuels for automobiles.
About 70% of all India coal consumption is for power generation.
These plants generated almost 60% of total generated power for the nation.
Thermal power generation in India grew from 27030 MW in 1985 to 86014 MW in
March 2007 out of which 26311 MW in 1985 to 71121 MW in March 2007 is due to
coal used thermal power generation.
The present annual growth rate of electric power consumption in India is 4%
Large point source (LPS) for NOx emission are mostly power plant (Coal, Natural
gas and Oil), Steel and cement plant, and large urban centers.
The regional distribution of these sector are well spread over the country.
However, the regional spread of overall NOx emission per unit area varies widely
across the Indian districts and has a close correspondence with coal
consumption pattern.
The emission also indicate a good correlation with population, level of
economical and Industrial activity.
The emissions per unit power generated have increased for some LPS between
1990 and 1995 indicating a reduction in performance. It may be due to various
reasons including high coal consumption per unit of power generated, poor
quality of coal used, use of inefficient thermal generation technologies, etc.
Almost all the plants in India use sub-critical pulverized coal technology without
any emission control equipment for SO2 and NOx. The newer plants contribute
more to total power generation and therefore to emissions.
Regional distribution of per unit area
coal consumption in India.
Regional distribution of per unit
area NOx emissions in India
Sectoral contribution to Indian NOx emissions
4
2
19
28
Energy (47%)
(Power and Indust)
19
28
Electrical Power Generation
Industry (energy use)
Road Transport
Biomass burning
Other Transport
Other Industries
Biomass peaking in
March- May
The increasing population and urbanization result in a 4 to 6% annual growth rate of energy
consumption in India, which enhances the emissions of NOx and other trace gases [UNEP,
2002].
Long-term air quality data over the residential and industrial locations of different Indian
cities indicate that NO2 levels are increasing steadily over major cities, and some of them
already exceed the permissible limits, as highas 100 to 240 mg/m3.
Different studies based on sector analysis and measurement campaigns show that NOx
emissions over India are expected to increase in the forthcoming years, even though these
estimates have large uncertainties for different sectors.
It is clear that more efforts are needed to understand the
spatial and temporal evolution of regional NOx
emissions over India with respect to the increasing
demand of energy consumptions and rapid urbanization.
Data from satellites provide valuable information to
improve estimates of NOx emissions as well as to
identify the source regions and to study the regional O3
chemistry in light of seasonal meteorology.
Regional spread of LPS locations
Major emission locations
Major Thermal Power Plants in India
Large number of TPP are
observed to distributed over the
Indo-Gangetic Basin.
Most of this TPP are located in
Urban, sub-urban centers.
Near coal mines area.
Surrounded by Industrial area.
Density of the TPP and major
industrial area is found to be
higher in the northern part of
India as compared to southern
India.
Wanakbori, Ukri, Bhurvaran
(2700 MW/day)
Nagpur, Korhadi (1200 MW/Day)
Delhi
Orba, Singrauli, Rihand
(>4000MW/Day)
Vindhyachal (2300 MW/Day)
Korba (3200 MW/Day)
Kota
Talcher (1500)
Chandrapur, 2340 MW/day
Ramagundam, 2600MW/day
Pune
Mumbai
Bangalore
Kottagudem (1200MW/Day)
Vijayawada (1300 MW/Day)
Raichur (1300 MW/Day)
Bokaro, Chandrapura, Durgapur,
Santaldih, Subermarekha, Culcutta
The location of emission hot spots correlates well with the location of
mega thermal power plants, mega cities, urban and Industrial Region,
emphasizing the contribution of emission through thermal power plants,
transport sector, and Industrial sector.
Emission Intensities are particularly higher over densely populated
Gangetic plains.
Satellite-retrieved NO2 columns shows maxima in the areas with mixed
urban, industrial and TPP sources, such as Bombay-Gujarat urban
corridor, and Punjab, Haryana, Uttar Pradesh, Zharkhand, West Bengal,
northern part of Chhattisgarh and Orissa industrial corridor.
Retrieved NO2 also shows emission from the individual TPP not mixed
with urban and industrial sources, such as Chandrapur (29, Installed
capacity 2340 MW/day) and Ragundam (44, 2100MW/day)
Data and Regression Model:
NO2 Data set for 11 year period (1996-1006).
Regression model is applied for 5 different region
1.
2.
3.
4.
5.
Mumbai Gujarat Golden Corridor
Delhi Region
Northeast and East India Industrial Sector
Southern Region
Central India
(lon=72-74, lat=18-23)
(lon=74-81, lat=26-32)
(lon=81-91, lat=20-27)
(lon=77-80, lat=10-13)
(lon=79-80.5, lat=18-21.5)
General expression for the regression model used for trend analysis
(Ziemke et al. [1997]) :
NO2(t) = b(t) + A(t).Trend(t) + Res(t)
Where, t
NO2(t)
b(t)
A(t)
Res(t)
=
=
=
=
=
Month index (1996-2006)
Time series NO2.
Seasonal cycle coefficient
Seasonal trend coefficient
Residual error time series for regression model
1. Mumbai Gujarat Golden
Corridor. (Urban centers,
transport, Power, Industrial
processes)
2
3
1
5
4
2. Delhi
Region
(Urban
centers, transport, Power,
Industrial
processes,
Biomass burning, Cement)
3. Northeast and East India
Industrial Sector (near coal
mine)
(Power,
Steel,
Cement transport, Urban
centers, Industrial process,
Biomass burning,)
4. Southern Region (Power,
Cement Urban centers)
5. Central India Power Plant
region (near coal mine).
(Power, Steel, Cement)
1.e1013 molecules/cm2
NO2 column amount (10
13
-2
molecules cm )
Temporal evolution of tropospheric NO2 column from 1996-2006 period over the
major emission region
600
550
500
450
400
350
300
250
200
150
100
Region-1
600
550
500
450
400
350
300
250
200
150
100
10 20 30 40 50 60 70 80 90 100 110 120 130
600
550
500
450
400
350
300
250
200
150
100
Region-3
10 20 30 40 50 60 70 80 90 100 110 120 130
600
550
500
450
400
350
300
250
200
150
100
Region-5
2.4 %/Year (1)
Region 2:
3 %/Year (1.1)
Region 3:
1.6 %/Year (0.7)
Region 4:
1.55 %/Year (1.1)
Region 5:
1.3 %/Year (1.1)
Region-4
All India : 1.4 %/Year (1)
10 20 30 40 50 60 70 80 90 100 110 120 130
10 20 30 40 50 60 70 80 90 100 110 120 130
650
600
550
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450
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250
200
150
100
Region-2
Region 1:
340
320
300
280
260
240
220
200
180
160
140
120
10 20 30 40 50 60 70 80 90 100 110 120 130
India
10 20 30 40 50 60 70 80 90 100 110 120 130
Months
However when OctoberMarch
months
are
considered the NO2 show
increase of about 3% and
4.7% / year over region 1
and 2 respectively. While
over India it is observed 2.1
%/year.
• According to the study conducted by Garg et al. (2001), NOx emission over the
Indian region growing at an annual rate of 5.5% /year, with a substantial
heterogeneity.
• Similarly, Badhwar et al. (2006) computed that NO2 concentration over Delhi is
growing at a rate of 3.8% /year (Vehicular growth during this period is 5.7%
/year).
• Ghude et al (communicated 2007) computed that surface ozone concentration
(based on monthly noontime and monthly mean of daily maximum values during
1997-2004 period) over Delhi is growing at the rate of 3.2% /year (Mega city in
region 1).
• Whereas Naja and Lal (1996) showed that it is growing of about 1.45% /year at
Ahamabad (Urban city in region 1).
• This suggests that the changes in NO2 column over the Indian region and
majority of selected industrialized regions are consistent and not dominated by
year to year variation.
The annual cycle of the tropospheric column NO2 above the major
emission region for the period 2003-2006 using SCIAMACHY
observations over India.
500
450
400
450
Region-1
400
350
300
350
250
300
NO2 column amount (10
13
-2
molecules cm )
200
150
330
Pronounced
seasonal
variation in NO2 concentration
is observed.
250
100
360
Region-2
200
450
Region-3
400
300
350
270
300
240
Region-4
250
210
200
Minimum is observed during
monsoon (JJAS) seasons over
India.
180
150
280
450
400
Region-5
260
240
350
300
220
250
200
200
180
150
India
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
160
MONTHS
maximum is observed during
winter to pre-monsoon period
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Comparison between tropospheric column NO2 derived from the satellite
measurement and in situ NOx measurements at surface level for
(using IR NOx analyzer) region 1 and 2.
20
450
14
350
12
300
250
22
DELHISURF
460
20
440
16
400
13
NO2 column amount (10
18
Region2
420
18
400
16
380
360
14
10
340
12
8
320
10
300
200
150
6
280
8
4
260
6
2
100
0
1
2
3
4
5
6
7
Months
8
9
0
10 11 12 13
NOx in PPB
Region1
PuneSurf
-2
molecules cm )
500
240
4
220
200
2
1
2
3
4
5
6
7
8
9
10 11 12
--
Months
Good agreement between the NO2 seasonal cycle measurements from satellite
and from ground based stations, demonstrates well the ability of SCIAMACHY to
detect pollution within the PBL.
Large seasonal variations of OH associated with photochemistry and moisture
transport through the monsoon circulation can be generally seen over India. Over
India strongest actinic fluxes are found in summer, leading to both high OH
production rates and high NO2 loss by photolysis, and consequently to a reduced
NO2 lifetime.
Biomass burning occurs mainly from January to may peaking in March and April,
and maximum emission of NOx due to biomass burning are estimated to occur
during this period. However, the contribution of biomass burning to NOx
production is less over India than the other tropical regions during their biomass
burning seasons. Biomass burned in the southern Indian states is very small (1.4
Tg/month) compared to eastern Indian states (6-7 Tg/months) and the western
Indian states (4.6 Tg/month).
Whereas during spring (pre-monsoon) although the lifetime of NO2 starts
decreasing (due to increase in solar actinic flux) biomass burning peaks (MarchApril) which sustain the higher NO2 concentration particularly over northern
Indian region.
NO2 Column amount (1013 molec/cm2)
Maximum concentration of tropospheric column NO2 occurs over an IG plain
despite moderate season to season variation.
Over middle to eastern part of IGP, western part of IGP (region 2 and 3) and
Mumbai-Gujarat Industrial corridor (region 1) prominent high concentration of
tropospheric column NO2 is observed during winter season.
A reasonable gradient of tropospheric column NO2 occur between southern part
and northern plain of Indian subcontinent.
Conclusion:
The location of emission hot spots correlates well with the location of mega
thermal power plants, mega cities, urban and Industrial Region, emphasizing the
contribution of emission through thermal power plants, transport sector, and
Industrial sector.
This suggests that the changes in NO2 column over the Indian region and
majority of selected industrialized regions are consistent and not dominated by
year to year variation.
Pronounced seasonal variation in NO2 concentration is observed with minimum
during monsoon and maximum during winter.
Good agreement between the NO2 seasonal cycle measurements from satellite
and from ground based stations, demonstrates well the ability of SCIAMACHY to
detect pollution within the PBL.
Southern Indian region dose not seem to be a large source of emissions as
compared to rest of the india.