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Analysis of Air quality trend over Delhi using Analysis of Air
quality trend over Delhi using
Met. Visibility, Satellites and CPCB Data and Met. Visibility,
Satellites and CPCB Data and
their impact on its Climatestheir impact on its Climates
Dr. Rajendra Kumar Jenamani Dr. Rajendra Kumar Jenamani
India Meteorological India Meteorological
DepartmentDepartment
IGI Airport, New DelhiIGI Airport, New Delhi
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ObjectivesObjectives
Analysis of Air quality trend over Delhi (CNG) Analysis of Air
quality trend over Delhi (CNG)
Met. Visibility and Fog data (Aviation data)Met. Visibility and
Fog data (Aviation data)
CPCB DataCPCB Data
Analysis of Impact Analysis of Impact
On ClimatesOn Climates
Except meteorological parameters, Pollution is the other
importaExcept meteorological parameters, Pollution is the other
important nt parameters causing Increasing Fog hoursparameters
causing Increasing Fog hours
Both increasing pollutions and increasing fog hours have caused
Both increasing pollutions and increasing fog hours have caused
decreasing Trend in Maximum Temperature because of dimming
decreasing Trend in Maximum Temperature because of dimming trend of
Sunlight over Delhi than brightening trend as happens trend of
Sunlight over Delhi than brightening trend as happens elsewhere in
the Westelsewhere in the West
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CPCBCPCB
ANNUAL/MONTHLY TREND ANNUAL/MONTHLY TREND
POLLUTIONPOLLUTION
OF CNG DELHI OF CNG DELHI
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13
18
23
28
33
38
A
n
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u
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l
m
e
a
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c
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c
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r
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/
m
3
5-yearly running means SO25-yearly running means NO2SO2NO2
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300
350
400
450
500
550
600
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
A
n
n
u
a
l
m
e
a
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c
o
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c
e
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t
r
a
t
i
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a
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g
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/
m
3
SPM 5-Yearly running means
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--0.2770.277--0.1380.1380.1270.127>5 KM>5 KM
--0.0340.0340.4940.494##--0.0480.048
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IMPACTIMPACT--PART IPART I
DELHIDELHI
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Variation and Linear Trend Analysis of monthly average Maximum
and Minimum Temperature of IGI and Safdarjung Airport
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Linking Trend of Fog hours and Linking Trend of Fog hours
and
TemperatureTemperature
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* Indicates >99.5%, ** indicates >99%, # indicates 97.5%,
$ * Indicates >99.5%, ** indicates >99%, # indicates 97.5%, $
indicates >95%, & indicates >90%indicates >95%, &
indicates >90%
--0.270.27--0.070.070.090.090.030.03--0.250.25--0.480.48##--0.470.47##--0.340.34&&SafdrajungSafdrajung
0.060.060.160.160.170.170.140.14--0.260.26--0.49**0.49**--0.470.47##--0.330.33&&IGI
AirportIGI Airport
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-0.6-0.5-0.4-0.3-0.2-0.1
00.10.20.30.40.50.60.70.80.9
1981
1983
1985
1987
1989
1991
1993
1995
1997
1999
2001
2003
Years
C
o
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r
e
l
a
t
i
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n
C
o
e
f
f
i
c
i
e
n
t
s
IGI M ax. Temp with V> =3000M IGI M in. with V> =3000mSFD
M ax with V> =3000m SFD M in with V>= 3000mIGI M ax. with
V90% level
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Met. Visibility record at IGI Airport of Delhi shows
deterioratiMet. Visibility record at IGI Airport of Delhi shows
deterioration on of Air cleanness in last 40of Air cleanness in
last 40-- yearsyears
It shows occurrences of reducing visibility 200m or less due It
shows occurrences of reducing visibility 200m or less due duedue to
the Intense fog events over IGI airport have been to the Intense
fog events over IGI airport have been increased by 7increased by
7--10 times from mid 1960s till recent for 10 times from mid 1960s
till recent for December December
While their frequencies has been increased up to 20While their
frequencies has been increased up to 20--times in times in January.
January.
In contrast, because of presence of haze/smoke/ fog/ pollutions
In contrast, because of presence of haze/smoke/ fog/ pollutions
etc., study of trends of number of hours per day with
visibilityetc., study of trends of number of hours per day with
visibilityreaching more than 5000m over the IGI at airport shows it
was reaching more than 5000m over the IGI at airport shows it was
highest in the start of 1964highest in the start of 1964--1968 with
16.8(17.0) hours which 1968 with 16.8(17.0) hours which
significantly decreased to .9(.7) hours i.e. to a one fifth
hoursignificantly decreased to .9(.7) hours i.e. to a one fifth
hours s during 1984during 1984--1988 in December (January). 1988 in
December (January).
Instead of stagnation in such high trends, the unusual Instead
of stagnation in such high trends, the unusual decreasing trend
continued till present period of 1999decreasing trend continued
till present period of 1999--2003 and 2003 and thus finally making
IGI airport, an unique airport in the world thus finally making IGI
airport, an unique airport in the world which have never been
experienced good visibility conditions which have never been
experienced good visibility conditions with visibility reaching
more than 5000m in the last few years with visibility reaching more
than 5000m in the last few years in December with average of only a
chance of half an hour to in December with average of only a chance
of half an hour to have such good visibility in January have such
good visibility in January
Conclusions Conclusions
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Pollutions levels of SO2 have been increased till 1994 from
Pollutions levels of SO2 have been increased till 1994 from 1991
and then their values remain stagnated till 1997. When 1991 and
then their values remain stagnated till 1997. When strict measures
was started to be implemented from 1998 , it strict measures was
started to be implemented from 1998 , it shows a decreasing trends
till 2005. But again increased shows a decreasing trends till 2005.
But again increased recentlyrecently
However in case of NO2, the most important pollutants which
However in case of NO2, the most important pollutants which can act
as CCN, have been steadily increased till 1995 from can act as CCN,
have been steadily increased till 1995 from beginning(1987) and
then decreased thereafter till 2001. This beginning(1987) and then
decreased thereafter till 2001. This decrease is very significant
as it was observed during the decrease is very significant as it
was observed during the period when there was an exponential growth
in number of period when there was an exponential growth in number
of vehicles and population. The most significant part of decrease
vehicles and population. The most significant part of decrease was
from 1998 till 2001 with increasing trend thereafter till was from
1998 till 2001 with increasing trend thereafter till 2006.
2006.
A study conducted by CPCB shows that 50 % of NO2 emission A
study conducted by CPCB shows that 50 % of NO2 emission comes in
air from vehicular activity and hence the fall in the comes in air
from vehicular activity and hence the fall in the levels of NO2
during 1998levels of NO2 during 1998--2001 for 2001 for
fewyearsfewyears can be related to can be related to the CNG
implementation. the CNG implementation.
Similarly like trend of NO2, SPM level at Delhi plotted shows a
Similarly like trend of NO2, SPM level at Delhi plotted shows a
general decrease from 1994 till 1997 which again decreased general
decrease from 1994 till 1997 which again decreased during
1998during 1998--2001. However in last 22001. However in last
2--years, there has been a years, there has been a slight increase
of SPM (Data of 2003). slight increase of SPM (Data of 2003).
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Hence, the effect of CNG conversion of public transport system
Hence, the effect of CNG conversion of public transport system and
other measures implemented by Govt. from 1998 to control and other
measures implemented by Govt. from 1998 to control various
pollutants over Delhi was though significantly able to various
pollutants over Delhi was though significantly able to control
raise of SO2 up to 2005 and the other two pollutants e.control
raise of SO2 up to 2005 and the other two pollutants e.g. g. NO2
and SPM during initial years of implementation, have been NO2 and
SPM during initial years of implementation, have been again started
increasing for last few years adding more CCN and again started
increasing for last few years adding more CCN and hence one of
reason due to which fog hours might be still hence one of reason
due to which fog hours might be still remaining higher of
Delhiremaining higher of Delhi
For the first time, present study unravels fall of average For
the first time, present study unravels fall of average maximum
temperature by 2maximum temperature by 2C to 3C to 3C over both the
stations at C over both the stations at Delhi in the peak winter of
January since 1989 with increase of Delhi in the peak winter of
January since 1989 with increase of average fog hours per day by 8
hours during the same periodaverage fog hours per day by 8 hours
during the same period
While minimum temperature shows a mixed and complicated While
minimum temperature shows a mixed and complicated response to such
alarming rising of fog.response to such alarming rising of fog.
Correlation coefficients computed among them also confirm that
Correlation coefficients computed among them also confirm that
maximum temperatures over Delhi are very strongly negatively
maximum temperatures over Delhi are very strongly negatively
correlated (correlated (--0.5 to 0.5 to --0.6) with fog hours which
again strongly 0.6) with fog hours which again strongly positively
correlated with pollutant levels (0.6), both significpositively
correlated with pollutant levels (0.6), both significant at ant at
> 99%. In contrast, non fog hours of visibility > 99%. In
contrast, non fog hours of visibility 3000m are 3000m are strongly
positively correlated (0.5) with both temperatures at strongly
positively correlated (0.5) with both temperatures at Delhi.
Delhi.
It is further interesting to find presence of mostly high CC
betIt is further interesting to find presence of mostly high CC
between fog hours ween fog hours with other meteorological
parameters e.g. with concurrent relatiwith other meteorological
parameters e.g. with concurrent relative humidity ve humidity