Trace Gas Measurements in IndiaTrace Gas Measurements in India

S. LalPhysical Research Laboratory,

Ahmedabad, India

Indo-US WorkshopChennai

July 12-16, 2006

Background

The tropical atmosphere is a vast natural photochemical laboratory with intense solar radiation and higher amount of water vapour. It is also a region of strong upwelling and convection.

Anthropogenic emissions of various trace gases are increasing due to rapid industrialization and urbanization specially in the Asian region.

Increasing levels of pollutants (gases and particulate matter) can perturb the natural chemistry, radiation balance and can cause environmental and climatic changes.

IPCC 2001

Anthropogenic Emissions of Pollutants

Emissions of air pollutants in Gg (Tg for CO2 only) during 2000

Country SO2 NOx CO2 CO CH4 NMHCs

China 20,385 11,347 3,817 115,749 38,356 17,432

Japan 801 2,198 1,203 6,806 1,143 1,920

Indonesia 884 1,317 587 23,105 6,443 6,903

India 5,536 4,591 1,886 63,340 32,851 10,844

Asia Total 34,316 26,768 9,868 278,564 106,821 52,150

America 16,498 25,038 5,840 94,033 61,450 17,907

Europe 33,337 15,603 4,642 85,424 34,195 20,750

Adapted from Streets et al., 2003 (JGR) for Asia while data for America (USA) are taken

from recent EPA report.

1990 2000 2010 2020

China 8273 13719 21906 32364India 3481 5615 10842 22824Indonesia 793 1630 2914 5090South Korea 977 1995 3131 4590Japan 2468 3168 3758 4271

NOx emissions during 1990-2020 (Gg NO2 /yr)

Van Aardenne (1999) AE

Anthropogenic emissions of NOx from Asia

Industrial & power plants : 45% Transportation sector : 37% Biomass burning : 18%

Streets et al. 2003, JGR

Tropospheric Ozone

Production Loss Balance

O3 + h O(1D) + O2

HO + O3 HO2 + O2

HO2 + O3 OH + 2O2

NO + O3 NO2 + O2

2

2 2

2 2420

2

2 3

4202 2 3

HO +NO NO +OH

__________________________2

nm

nm

CO OH H COH O M HO M

NO hv NO OO O M O M

CO O CO O

Dry Deposition

Similar set of reactions for CH4 and NMHCs

Environmental impact of O3 exposure:

Crop yields Human Health

Lungs

Respiration

Ozone is the only source of OH radicals which are known as ‘detergent’ in the troposphere.

O3 + h -> O(1D) + O2

O(1D) + H2O -> 2OH

Chemistry

Radiation forcing

Forster and Shine, 1997

Role in Chemistry and Climate

Mount Abu 1700m

Gadanki Port Blair

Trivandrum

Ahmedabad

ISRO-GBP : Monitoring of Ozone and Related Gases

•An increase in surface level ozone concentration from 1954-55 to 1991-93 at 0.5%/year is found over Ahmedabad.

• Efficiency of O3 production more at rural sites than at urban sites. Lower net

surface ozone production (0.15 O3 /CO) over the Indian region as compared to

in US or Europe (0.35 O3 /CO).

Comparison with a 3D Model

Model of Atmospheric Transport and Chemistry (MATCH)

Naja and Lal, GRL 1996Lal and Lawrence, GRL 2001

Measurements over the Bay of Bengal

Percentage compositions of C2-C4 NMHCs

At Ahmedabad, local emissions of various NMHCs play very important role while at Mt. Abu transport from the source regions is a key parameter in their distributions.

Among all the NMHCs measured, propane dominates at Ahmedabad while it is ethane at Mt. Abu.

Sahu and Lal, AE, 2006

NPL & CRRIPRLIITMNRSA AUIISc & AntpUSPL

RoutesFor Feb. 2004

Shadnagar/Hyderabad

Distance Travelled ~ 15000 kmNumber of Stations ~ 150Number of Participants ~ 50

ISRO GBP Land Campaign I - Feb. 2004

ISRO GBP Land Campaign II – Dec. 2004 Land Campaign II - Dec. 2004

H issar

N ew D elh iN ain ita l

A graK anpur

A llahabad

JadugudaK haragpur

Land Campaign II - Dec. 2004

H issar

N ew D elh iN ain ita l

A graK anpur

A llahabad

JadugudaK haragpur

H issar

N ew D elh iN ain ita l

A graK anpur

A llahabad

JadugudaK haragpur

17 Indian Institutes and Universities participated

Transport and Transformation of Pollutants

• Higher levels of ozone at rural/ remote sites. Efficiency of O3 production more at rural sites than at urban sites.

•Dominance of fossil fuel combustion related emissions based on measured NMHCs and other gases.

• Higher levels of ozone at rural/ remote sites.

• Dominance of Fossil fuel combustion related emissions based on first time measured NMHCs and other gases.

•No clear diurnal variation during foggy days

LC-II, Dec. 2004

AHMEDABADHISAR

KANPURCHIN

A US

EUROPE

CO

/NO

x

0

10

20

30

40

Transport and transformation of pollutants

Increasing anthropogenic emissions : Impact on chemistry and climate

GOME satellite

Akimoto (2003), Science

Brasseur et al., GRL 1998

Past and future changes in global tropospheric ozone

NH Mid lat : Boundary Layer : 80 % (15 ppb) Free Troposphere : 40-70 % (20-40 ppb)

1850 to 1990

1990 to 2050IPCC scenario IS92a ‘medium case’CO : 1.7 fold increaseNOx : 2.1 fold increaseNMHCs : 2.4 fold increaseLarge (3-7 fold) changes in SE Asia and Africa

Focus of tropospheric research on chemistry-climate interactions over the Asian region

Prather et al JGR 2003

“Understanding the processes that connect emissions (source precursors) to abundances and abundances to the climate forcings are essential for an accurate prediction of the future climate and an assessment of the impact of climate change and variations on the earth system.”

SPARC-IGAC

Stratospheric Processes and their Role in the Climate

2100

Future Plans

ISRO GBP - Ground based monitoring stations

Longterm measurements of CO, NOx, O3, SO2 , HCs etc will be made at selected sites to study their emission fluxes and changes in their concentrations.

Mountain sites : Mt. Abu Nainital (Towers will also be useful)

Remote/ : Port Blair Rural sites Gadanki Thumba Shillong Roorkee

Urban sites : Ahmedabad Kanpur Bhubneswar/Visakhapatnam/Chennai

Detailed measurements of trace gases will be made along with meteorological parameters (temperature, humidity, winds, solar and IR radiation etc.). Also these measurements will be supported by chemical-transport 3D models.

Satellite based measurements of key pollutants (like CO, O3, aerosol) are needed to study future changes in this region.

• Low inclination satellite• Limb and nadir viewing • High resolution spectrometer 2 - 16 m.

Trace gases measurements from space

Summary

In view of the increasing levels of trace gases due to anthropogenic activities, there is a need to know their emissions and their impacts on environment and future climate.

We plan to study levels and changes occurring due to natural as well as anthropogenic processes in different regions of India using ground based, aircraft and satellite based measurements.

These observation will be supported by 3D model simulations.

Thanks