atmospheric chemistry: from air pollution to climate …mhavas/ariya-50.pdfatmospheric chemistry:...
TRANSCRIPT
Parisa A. Ariya
Department of Atmospheric and Oceanic Sciences
& Department of Chemistry
Atmospheric Chemistry:
From air pollution to climate science
THE ORIGINS OF ATMOSPHERIC SCIENCES AT McGill
•Appointed Professor of Meteorology at
McGill 1856
•Move observatory to McGill 1862
Modified from Daniel Jacob, 1999
Primary Aerosols
aerosols?
Secondary aerosols
aerosols & cloud
drops
Chemical reactions
(e.g., h, HO, O3, …)
Hg
Influence of chemistry on
atmospheric physics
AryaResearch Team
Training HQP: 1998-2010
•15 graduated students (PhD and MSC)• 8 PDF•+ 50 interns and undergraduates•Alumni: 5 faculty members, 2 CEO •Rest: in industrial & environmental agencies
ARIYA RESEARCH TEAM
1. Tropospheric
photochemistry
4. Development of new
methods and Technology For
trace gaseous and
particulate analysis
Aerosols / clouds
Bioaerosols
Research
Themes
2. Chemical
physics of trace
metals in
atmosphere and
atmospheric
interfaces
5. Development of
techniques
for pollution
remediation
3. (bio)organic compounds at
air/water-ice interfaces: Bioaersol
nulceation
Laboratory, field and modeling
complementary approach
High Resolutions
Fourier Transform
Infrared
and FTIR/Raman
SpectrometersA
Mass Spectrometers
(APCI, ESI, GC/MS)
Pump
Pump
UV/Vis lamps
Multipath Cell
Short
Temperature-controlled
Cell
A
HPLC
UV/VIS
Femto second
laser
ATR-FTIR
CVAFS
GC/FID
HPLC
TEM-EDS
Simplified schematic of state of the art
facilities at McGill AC-laboratories
Full facility for air quality: O3, CO, CO2, VOC, aerosols,
Bioaerosols, NOx, SOX analyzers – Ice nucleation
CW diode
pump laser
HW1P1
710-980nm; ~100fs
>700mW
~9J per pulse
Sample
532 nm; 6W
L1
Ti:sapphire laser
PDM1
F1
M3
BS2
I1
CL1CL2
BS1
P2
M2
I2
PC
Preamplifier &
Single Photon
Counter
PMT
Mono-
chromator
High Voltage
Supply
L4F3
F4 F2
M4
BBO
L5
CL3CL4
F5
Detection
Reference Signal
Beam Diagnostics
355 to 490 nm
Legend
M = Mirror PD = Photo Diode
L = Lens CL = Collecting Lens
F = Filters BS = Beam Splitters
I = Iris HW = Half Wave Plate
P = Polarizer BBO = Frequency Doubling
Crystal
PMT = Photo Multiplier
Tube
Second Harmonic Generation (SHG) setup
Transmission Geometry
Surface Chemistry – SHG
(study of chemical equilibrium of molecules at
the colloidal and planar, liquid/solid, gas/liquid,
and liquid/liquid interfaces)
Using multi-pass long path cavity setup absorption spectra of trace
concentration of gaseous molecules and atom can be measured
Kinetic rate constants can be determined for reactions taking place in the
order of micro-seconds
Fluorescence decay experiments provide information about the lifetime
of reactive radicals and molecules in gas and liquid phase
By means of super-continuum generation of visible light source will
enable us to detect and monitor the appearance and/or disappearance of
multiple speciesin the course of a reaction simultaneously
Absorption and Fluorescence Spectroscopy
Tropospheric ozone depletion & MDE
Schroeder et al., Nature, 1998
Ozone and mercury depletion events
Scheme 1:
Hg0 + X2 /X Hg + 2X HgX + X HgX2
Scheme 2:
Hg0 + XO HgOX
HgO + X
HgX + O(1D)
(X = F, Cl, Br, I)
Scheme 3:
Hg0 + O3 HgO + O2Scheme 4:
Hg0 + HO HgOH
Ariya et al., J. Phys. Chem 2002VIswanathan & Ariya, 2002Khalizov, Bala, Ariya, J. Phys. Chem. 2003
Raofie and Ariya, 2003
Pal and Ariya, 2003
Pal and Ariya, 2004
Redox systems:
33 oxidation & 16 reduction
HgOBrHgO
HgBr
Mass spectra of HgOBr, HgBr, HgO
Mercury AerosolsRaofie and Ariya, EST, 2004
First evidence for stable Hg+ in transient
intermediates
Impact of water on O3 + Hg(0) Snider and Ariya, PCCP, 2008
ba
Impact of water clusters on O3 + Hg Formation of clusters
Elevated Hg levels on sea ice; up to 90% associated with particles of 0.45 – 2.7µm size
Poulain, Amyot, Ariya. 2008 GeochimicaCosmochimicaActa(top hot article; cover page, faculty 1000 choice)
Hg speciation in arctic snow
Role of exudates addition (whole cells experiments not shown)
Biogenic organics
Exudates production
0.2 µm
Sea water
Freshwater
Poulain, Amyot, Campell, and Ariya, Environmental Science &Technology. 41 (6): 1883 -1888, 2008 (hot article).
Biological and chemical Hg redox
transformation in Arctic waters
Deposition Emission
* Rolf Sander, MPI
*210 gas-phase reactions,
*19 photolysis reactions
*20 liquid photolysis Phase
* Three types of Aerosols
(sea salt, sulfate urban, and
sulfate remote)
* Mercury reactions are added
MOCCA & MOCCA-ICE
Ariya, Dastoor, Shroeder and Barrie, Tellus, 2004; Dastoor, et al., EST, 2008
Arctic: A sink for mercuryArctic: A sink for mercury
Modified from Daniel Jacob, 1999
Primary Aerosols
aerosols?
Secondary aerosols
aerosols & cloud
drops
Chemical reactions
(e.g., h, HO, O3, …)
Hg
Influence of chemistry on atmospheric
physics
FF
F
O
OO N
F F
F
ONF
F
F
F
ONH2
F
F
F
F
F
+
PFBHA Bis(PFBHA) dioxime methylglyoxal
Solid phase micro-extraction (SPME)
Volatile Organic Compounds & the Atmosphere
Sea water & airSnow and airGC-FID
GC-MS
GC-FID
GC-MS
VOC Chemistry
octanal nonanal
0.06 5.5
octanal nonanalbutanal pentanal
0.28 1.76.0 4.7
Hudson, E.D.; Ariya, P.A. Environ Chem, in preparation3. Jumars, P.A. et al., Mar Microb Food Webs 1993
2. Wanninkhof, R., J Geophys Res 1992
1. Williams, J et al., Geophys Res Lett 2004
4. Hayduk, W.; Laudie, H. AlChE J. 1974
F = k(Cw – Hca ) 1
k = 0.31u2(660/Sc)0.52
Sc = ν/D 3,4
5. Zhou, X.L.; Mopper, K. Environ Sci. Technol .1990
butanal 80 pptv
pentanal 100 pptv
octanal 100 pptv
nonanal 150 pptv
Sargasso Sea5
Estimated carbonyl compound fluxes in the
North-western Atlantic (µmol/m2/day; medians)
Ocean a sink or a source for VOC
Bacillus cereus16s-rDNA sequence:
• GGCaAtTgCGCGTCGCAGCCGTCCTTAGCATGCCAGTCGATTCGAATGGATTGAGAGCTTGCTCTCAAGAAGTTAGCGGCGGACGGGTGAGTAACACGTGGGTAACCTGCCCATAAGACTGGGATAACTCCGGGAAACCGGGGCTAATACCGGATAATATTTTGAACTGCATGGTTCGAAATTGAAAGGCGGCTTCGGCTGTCACTTATGGATGGACCCGCGTCGCATTAGCTAGTTGGTGAGGTAACGGCTCACCAAGGCAACGATGCGTAGCCGACCTGAGAGGGTGATCGGCCACACTGGGACTGAGACACGGCCCAGACTCCTACGGGAGGCAGCAGTAGGGAATCTTCCGCAATGGACGAAAGTCTGACGGAGCAACGCCGCGTGAGTGATGAAGGCTTTCGGGTCGTAAAACTCTGTTGTTAGGGAAGAACAAGTGCTAGTTGAATAAGCTGGCAcCTTGACGGTACCTAACCGAGGAAAG
Air-snow interactions of bioaerosols
Ice nucleating efficiencies of bioaerosols
BacteriaLeafFungiPollen
He
ight (K
m)
Time (min)
0.05
1e-2
1e-3
1e-04
1e-05
1e-06
(L-1)
Evolution of ice-nucleus-containing ice pellet concentrations
in immersion freezing mode
Sun, Ariya, Leighton and Yau, Geo-physcial Research Letter, 2010.
Ice nucleating efficiencies of bioaerosols impact the initiation time
and concentrations of primary ice pellets
Acknowledgments of Funding Agencies
•NSERC (discovery, strategic, network)
• CFCAS (project, group, and network)
•FCAR –FQRNT (nouveau chercheur,
Professeur-chercheur, centre and strategique)
•CFI
•McGill (Dawson chair fund)
•Environment Canada
•CSA
•EU - MPI
•NOAA
•NATO
•CNRS