new insights on emission and chemistry of vocs from high
TRANSCRIPT
Vinayak Sinha
Indian Institute of Science Education & Research Mohali
ACAM Workshop, 9-12 June, Kathmandu
New insights on emission and
chemistry of VOCs from high time
resolution in-situ measurements in
the Himalayan foothills
Source: Jim Giles, Nature 2005, Vol 435
Asian region :
expected to be
a global hotspot
The Himalayan Foothills : Why ?
VOCs , The Radical Precursors and Emission
Tracers Measured Routinely in Mohali
Isoprene :
Pinene :
O
Methanol :
Dimethyl sulphide :
Marine air tracer
OH
NAcetonitrile :
Acetone :
All at pptV level
sensitivity with
PTR-MS
Acetaldehyde : O
H
Aromatics : Traffic and solvent
Benzene : Toluene :
C-8 and C-9
Aromatics :
OVOCs
Biomass burning tracer
BVOCs
Carc
ino
ge
ns &
SO
A p
recu
rso
rs
http://www.iisermohali.ac.in/facilities/AtmosChemfacility/index.html
IISER Mohali Atmospheric Chemistry Facility-I
Ozone
Nitrogen
Oxides
Carbon
Monoxide
Sulphur
Dioxide
PM 2.5
PM 10
Wind
direction
Wind speed
RH, Temp
Solar
radiation
1 measurement / minute
Installed at
IISERM in
August, 2011
IISER Atmospheric Chemistry
(www.iisermohali.ac.in/facilities/AtmosChemfacility/index.html)
First PTR-MS in India;
Been measuring from
August 2011- till date (June 2013)
Continuous ~2 year in-situ dataset on VOCs, CO
NOx, SO2, PM 2.5, PM10 etc..
Those interested in data/collaborations
welcome to contact me:
Proton Transfer Reaction Mass
Spectrometry (PTR-MS):
Can measure VOCs at ppt level;
Isoprene, Acetaldehyde, Benzenoids and about
40 VOCs present in ambient air
Trace gas inlets at IISER Mohali Air Quality Station
IISER Mohali Atmospheric Chemistry Facility-II
INSIGHT 1: EMISSIONS FROM OPEN
CROP RESIDUE BURNING AND IMPACT
ON REGIONAL AIR QUALITY
Day one: Similar back
trajectory, crop residue
burning absent
72 hour back trajectories
for both Mohali and Delhi
and 96 hour fire counts data
were considered
Air masses had
experienced considerable
contact time over regions
where crop residue
burning was active
• Back trajectory calculations were done using NOAA HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory Model) GDAS (Global Data
Acquisition System) meteorology http://ready.arl.noaa.gov/HYSPLIT.php.
•Moderate Resolution Imaging Spectroradiometer (MODIS) (NASA/University of Maryland, 2002, MODIS Hotspot / Active Fire Detections Data set,
http://maps.geog.umd.edu) remote sensing fire count data was used
Air Mass Back Trajectories on Two Days
Day two: Similar back trajectory
as day one, crop residue burning
is active
Sarkar, Kumar and Sinha, Curr.Sci.,2013
8
6
4
2
CH
3C
N (
pp
bv
)
18:00 21:00 00:00 03:00
Local Time (IST)
8
6
4
2
4x103
3
2
1
0
CO
(pp
bv
)
4x103
3
2
1
0
16
12
8
4
0
Be
nze
ne
(pp
bv
)
16
12
8
4
0
50
40
30
20
10
0
To
lue
ne
(p
pb
v)
50
40
30
20
10
0
100
50
0
NO
x (
pp
bv) 100
50
0
3-4 Nov (fire)
5-6 Oct (clean)
Back Trajectory Arrival Time
Peak values of 100 ppb NOx , 40
ppb Toluene and 16 ppb Benzene
(> 30 minutes) on Day 2 (associated
with extensive crop residue burning)
Increase (shaded bar) starts with
the arrival of air masses at the site
Ambient levels where crop residue
burning actually occurs would be
much higher than the levels
measured at Mohali (a downwind
site)
Comparison of CO, NOx and Selected VOC
levels on Day 1 & 2
Sarkar, Kumar and Sinha, Curr.Sci.,2013
INSIGHT 2: Regional Isoprene &
MT : How important could it be?
Source: India State of Forest Report, 2011
Ministry of Environment & Forests
Government of India
The Famous BVOC Couple
Source: Alex Guenther et al. ACP,
2006
Isoprene and MT dominate Global VOC emissions (550 Tg /yr & 100Tg/yr)
Influence atmospheric oxidation, ozone and SOA formation
Affect air quality and climate
X But no in-situ ambient air measurements of these BVOCs within India!
Wheat and poplar Sugarcane and poplar
Turmeric and poplar
Images from North India
Courtesy : Manish Pareek (IISERM) & K. Bangarwa (Haryana Agricultural Univ)
We Indians like our cities and
campuses to be green !
Summer Monsoon: Box Whisker Plot
SUSKAT: 1st PTR-TOFMS Deployment in South Asia: IISER-IASS-ICIMOD Collaboration made it possible
Separation of furan and isoprene using
PTR-TOF-MS
Furan and isoprene are nominal isobars
Isoprene* at 69.0704
Furan* at 69.034
*Protonated Mass
Furan is a Combustion Tracer
Isoprene is a Biogenic Tracer 550 Tg/yr out of 1300 Tg/yr
SusKAT Supersite at Bode,Kathmandu
Figure courtesy:
Maheswar Rupakheti,
IASS, Postdam; Arnico, ICIMOD
First Results : PTR-TOF-MS SUSKAT
(ace
ton
itri
le)
(be
nze
ne)
Figure courtesy:
Chinmoy Sarkar,
IISER Mohali
INSIGHT 3: REACTIVITY OF MOHALI AIR
OH Reactivity System at IISER Mohali
OH Reactivity Budget at Mohali: Importance
of Reactive Oxidation Products!
Morning time data:
April 13, 2013
Afternoon time data:
April 13, 2013
SUMMARY
Practice of crop residue burning emits reactive VOCs, NOx and CO
PM, causing intense perturbation to regional atmospheric composition ;
Frequent ozone exceedance events / aggravates smog episodes; HCN,
Isocyanic acid ?
Biogenic emissions in IGP have been mostly overlooked;
Isoprene and Monoterpenes in IGP some seasons comparable to forested
regions; land use practices major factor
Atmospheric composition and reactivity in photochemically aged air
masses is not well understood (complex/higher) (e.g. Sinha et al., ACP,
2012)
Secondary photo- oxidation chemistry & comprehensive radical ,
chemical process studies needed
New in-situ fast measurements will improve emission inventories;
improve air quality forecasts
http://www.iisermohali.org/AtmosChemfacility/index.html
Ozone
Nitrogen Oxides
Carbon Monoxide
Sulphur Dioxide
PM 2.5
PM 10
Wind direction
Wind speed
RH, Temp
Solar radiation
40 VOCs
1 measurement every minute
IISER Mohali Ministry of HRD, India
Max Planck Partner Group-DST Partner group;
ICIMOD & IASS Postdam
Saryu Garg , Vinod Kumar, Prafulla
Chandra & Chinmoy Sarkar (L to R )
ACKNOWLEDGEMENTS