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

RADAR GROUPIN 1940s

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

MinamataMinamata disaster

Tropospheric ozone depletion & MDE

Schroeder et al., Nature, 1998

Ozone and mercury depletion events

What about people?What about the living organisms?

Reactive Halogens

Platt et al., GRL, 2002 Ariya et al., J. Atmos.Chem., 1999

Reactive Halogens

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

Importance of Br in destruction of Hg0Importance of Br in Hg depletion

Ariya, Dastoor, Shroeder and Barrie, Tellus, 2004; Dastoor, et al., EST, 2008

Arctic: A sink for mercuryArctic: A sink for mercury

IPCC, 2007

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

Alert and Alaska

Sampling snow

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

Bacte

ria

count

(CfU

/ml)

Fungi c

ount

(CfU

/ml)

Bioaerosols: Atmosphere and snow

Bacillus cereus16s-rDNA sequence:

• GGCaAtTgCGCGTCGCAGCCGTCCTTAGCATGCCAGTCGATTCGAATGGATTGAGAGCTTGCTCTCAAGAAGTTAGCGGCGGACGGGTGAGTAACACGTGGGTAACCTGCCCATAAGACTGGGATAACTCCGGGAAACCGGGGCTAATACCGGATAATATTTTGAACTGCATGGTTCGAAATTGAAAGGCGGCTTCGGCTGTCACTTATGGATGGACCCGCGTCGCATTAGCTAGTTGGTGAGGTAACGGCTCACCAAGGCAACGATGCGTAGCCGACCTGAGAGGGTGATCGGCCACACTGGGACTGAGACACGGCCCAGACTCCTACGGGAGGCAGCAGTAGGGAATCTTCCGCAATGGACGAAAGTCTGACGGAGCAACGCCGCGTGAGTGATGAAGGCTTTCGGGTCGTAAAACTCTGTTGTTAGGGAAGAACAAGTGCTAGTTGAATAAGCTGGCAcCTTGACGGTACCTAACCGAGGAAAG

Air-snow interactions of bioaerosols

13C NMR

Microbial activities in snow

Ariya et al., Environmental Chemistry, 2010, in press

Microbial activities: Change is snow

microphysics and air-snow partitioning

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

Happy Anniversary AOS

&

Have a wonderful day!