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

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

CPCBCPCB

ANNUAL/MONTHLY TREND ANNUAL/MONTHLY TREND

POLLUTIONPOLLUTION

OF CNG DELHI OF CNG DELHI

13

18

23

28

33

38

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5-yearly running means SO25-yearly running means NO2SO2NO2

300

350

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550

600

1987

1988

1989

1990

1991

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1994

1995

1996

1997

1998

1999

2000

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2002

2003

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SPM 5-Yearly running means

--0.2770.277--0.1380.1380.1270.127>5 KM>5 KM

--0.0340.0340.4940.494##--0.0480.048

IMPACTIMPACT--PART IPART I

DELHIDELHI

Variation and Linear Trend Analysis of monthly average Maximum and Minimum Temperature of IGI and Safdarjung Airport

Linking Trend of Fog hours and Linking Trend of Fog hours and

TemperatureTemperature

* 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

-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

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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

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

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).

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