Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans–...

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Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute for Space Aeronomy, Brussels, Belgium Eurochamp 2 Workshop, Manchester, 2011

Transcript of Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans–...

Page 1: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

Parameterization of SOA formation for α-pinene, based on a detailed mechanism

Karl Ceulemans– Steven Compernolle – Jean-François Müller

Belgian Institute for Space Aeronomy, Brussels, Belgium

Eurochamp 2 Workshop, Manchester, 2011

Page 2: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

Outline

BOREAM: Detailed model for α-pinene SOA

Simulations of smog chamber experiments

10-product model parameterization including ageing

Page 3: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

BOREAM : explicit model for α-pinene SOA

Gas phase reaction model with additional generic chemistry and aerosol formation module

10000 reactions, 2500 compoundsUsing KPP solverCapouet et al. (2008), Ceulemans et al. (2010)

Page 4: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

Explicit chemistry• Based on

advanced theoretical calculations and SARs

• Oxidation by OH, O3 and NO3

• Oxidation products react with OH or photolyse (now also in aerosol phase)

• Vapour pressure method: Capouet & Müller (2006)

Page 5: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

Generic chemistrySecond generation oxidation products lumped

into semi-generic and generic products

• Semi-generic: carbon number and functional groups

• Generic: carbon number, vapour pressure classes (11) and 1explicit functional group

LA10HPP

10 carbons1 alcohol &2 hydroperoxide

Implicit parent structure, with pvap,im

LX9cONO2

Page 6: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

Smog chamber Photo-oxidation

low-NOx experiments (Ng et al. 2007)

α-pinene and O3 given in Valorso et al. (2011)

Initial: 330 ppt NO, 330 ppt NO2 , 4 ppb O3 , blacklights

α-pinene decay well-reproducedozone : reasonable agreement, sensitive to

assumptions!

Page 7: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

Smog chamber Photo-oxidation: SOA evolution

for Ng et al. 2007 exp. 1 (low NOx):

SOA mass yields are overestimated: experimental SOA yield is 40%, BOREAM simulation: 60%

Page 8: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

Smog chamber Photo-oxidation: SOA composition

Molar composition for Ng et al. (2007) exp. 1 (low NOx):

SOA is dominated by hydroxy dihydroperoxidesParticle phase chemistry of hydroperoxides?

Page 9: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

Model performance: Photo-oxidation

two low-NOx experiments, (Ng et al. 2007) ; somewhat overestimated

most SOA yields within factor 2

*

Page 10: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

10-product parameter model

5 scenarios: ◦ OH (low and high-NOx )

◦ O3 (low and high-NOx )

◦ NO3 (high-NOx)

Products fit to full model simulations with ageing

Diurnal cycle for VOC, OH, HO2 and O3 ; deposition

SOA equilibrium after 12 days

APOHHO22' APOHHO21' HO APINOHO2

NO APOHNO2' APOHNO1' NO APINOHO2

APINOHO2 OH APIN

432

221

Page 11: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

Two-product model parameterizations Odum (1996)

Y : SOA mass yield

M0 : absorbing organic mass

αi : mass stoichiometric coefficient of product i

Ki : Pankow (1994) absorption

equilibrium constant

i i

ii

MK

KMY

00 1

gasi

aerii CM

CK

,0

,

.

Page 12: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

Temperature dependence of parameters

Absorption equilibrium constant:

Stoichiometric coefficient

)())11

(exp()()()( ,,rr

i

rripip m

m

TTR

H

T

TTKTK

))298(exp()( 10 TT iii 0°C

30°C

Page 13: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

10-product model parameters

)())11

(exp()()()( ,,rr

i

rripip m

m

TTR

H

T

TTKTK

))298(exp()( 10 TT iii

0i 1

i )298(,ipK iHscenario product m3 µg-1 kJ mol-1

α-pinene + OH, low NOx

1 0.307 -0.022 6.98 85.6

2 0.211 -0.0135

0.117 22.2

α-pinene + OH, high NOx

3 0.028 -0.040 0.762 132.2

4 0.109 -0.025 0.00486

85.3

α-pinene + O3, low NOx

5 0.282 -0.0132

4.155 86.8

6 0.142 -0.025 0.0158 77.1

α-pinene + O3, high NOx

7 0.016 -0.057 0.837 161.8

8 0.213 -0.0054

0.00326

111.4

α-pinene + NO3 high NOx

9 0.018 -0.049 0.493 172.4

10 0.251 -0.015 0.00092 147.6

i i

ii

MK

KMY

00 1

APOHHO22' APOHHO21' HO APINOHO2

NO APOHNO2' APOHNO1' NO APINOHO2

APINOHO2 OH APIN

432

221

APO3HO22' APO3HO21' HO APINO3O2

NO APO3NO2' APO3NO1' NO APINO3O2

APINO3O2 O APIN

872

265

3

Reactions

APNO32.' APNO31' NO APIN 1093

OA

pineneii MW

MWTT ).()('

Page 14: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

10-product model curves at 298K

More SOA in low-NOx than in high-NOx (factor 8 difference)

α-pinene + OH leads to more SOA than α-pinene + O3

Page 15: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

Why more SOA in low than high-NOx ?

++ O2

OH OHO O

+ NO

OHO NO210%

+ NO 90%OH

O

decomposition

OO

pinonaldehyde

+ HO2

OHO OH

++ O2

OH

O

OHO OH

O

+ HO2

O

OHO OH

OH

O2

OH++

OO

O O

NONO2+ +O

O

O ON

O

O CH2

O + CO2

High-NOx

Low-NOx

Hydroperoxides (condensable)

Peroxy acyl nitrates

nitrates

More decompositionsMore volatile products

Page 16: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

Verification at intermediate NOx

Full model

parameter model(modified)

Page 17: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

Sensitivity to photolysis and oxidants

Not accounting for photolysis of SOA during ageing

Accumulation of condensables very high yields

Not very sensitive to chosen OH or HO2

Page 18: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

Comparison with other parameterizations

Low-NOx :

Yields in this study are higher than for others, ◦ Aging impact

◦ Very low-NO x

But, also high yields in

Ng et al. (2007)

High-NOx :

similar to Presto et al. (2005)

T = 298 K

Page 19: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

SummaryBOREAM simulations of smog chamber photo-

oxidation: most SOA yields within factor 2Some overestimations for low-NOx

10-product model fit to explicit box model BOREAM including aging

Low-NOx SOA higher than previous parameterizations based on smog chambers (impact aging)

Photolysis of compounds in aerosol phase important

EVAPORATION: New vapour pressure estimation method

Page 20: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

Thank you for your attention!

Page 21: Parameterization of SOA formation for α-pinene, based on a detailed mechanism Karl Ceulemans– Steven Compernolle – Jean-François Müller Belgian Institute.

α-pinene + O3 and pinonaldehyde chemistry