Development and Application of CACM/MPMPO

Development and Application of
CACM/MPMPO
R.J. Griffin 1 , J. Chen 1 , C.E. Jordan 1 , H. Mao 1 , R.W.
Talbot 1 , S. Vutukuru 2 , and D. Dabdub 2
1
UNH, 2 UCI
December 6, 2006
International Conference on Atmospheric Chemical
Mechanisms

Polycyclic
Low Y
Functionalized Hydrocarbons
Primary
VOC
Aromatic
Non-Arom.
Aromatic
Non-Arom.
Monoaromatic
Alkanes
Alkenes
Biogenics
Phenolic
Aldehydic
Acidic
Carbonyls
Ethers
High Y
C 2 -C 6
C 6 -C 12
C 13 +
Ethene
C 3 -C 6
C 7 +
Terpenes
Isoprene
Aldehydes
Ketones
MeOH
EtOH
α-Pinene
β-Pinene
d-Limonene
Low Y
High Y
HCHO
CH 3 CHO
C 3 +
C 3 -C 6
Alcohols
C 3 +
C 7 +

Surrogate Determination
Example:
AROL – low SOA yield aromatics: two or more methyl
substituents
3 xylene isomers
3 TMB isomers
3 TetMB isomers
More highly substituted}
Average C#: ~9 TMB
1,2,3-TMB
k OH
,
prevalence

The Mechanistic Approach
A + ox
α RP/UR 1
}
if α, β, and γ have
β RP/UR 2 been determined
γ RP/UR 3
ox
…
(1−α−β−γ) RO 2 i
NO
ξ ROi + ξ NO2 + (1-ξ) APi
OH
RP/UR
isomerization
decomposition
reaction with O 2
RP/UR

Example Chemistry
Now over 500 reactions to describe the formation of SOA precursors,
ozone, and other photochemical pollutants (Griffin et al., 2002, 2005;
Chen and Griffin, 2005)

Formation of SOA
VOC + ox
P 1 , P 2 , …P n
G 1 ,G 2 ,...,G n
A 1 ,A 2 ,...,A n
AQ 1 ,AQ 2 ,...,AQ n
K om,i
Partitioning Theory
A i
/ M o
= ∼
G i
Griffin et al. (2003, 2005)
RT
p o L,i MW om γ i
Henry’s Law and
Dissociation
H i
= γ i
aq
AQ i
/G i
AQ i AQ i - AQ i
2-
Inorganics using ISORROPIA

Simulation of Chamber Experiments
700
70
NO, NO 2 and O 3 mixing ratio (ppb)
600
500
400
300
200
100
0
d-limonene
NO
0 30 60 90 120 150 180
Time (min)
O 3
NO 2
60
50
40
30
20
10
0
d-limonene mixing ratio (ppb) -
Experiment: Griffin et al. (1999)
Simulation: Chen and Griffin (2005)

Simulation of Chamber Experiments
SOA (µg m -3 )
40
30
20
10
Predicted
Observed
0
0 100 200 300
Time (min)
Experiment (α-pinene + O 3 ): Griffin et al. (1999)
Simulation: Chen and Griffin (2005)

Simulation of Chamber Experiments
Predicted SOA / Observed SOA
3.0
2.0
1.0
0.0
α-pinene
β-pinene
d-limonene
1 10 100 1000
Observed SOA (µg/m 3 )
Experiments: Odum et al. (1996); Hoffmann et al. (1997); Griffin et al. (1999)
Simulations: Chen and Griffin (2005)

Implementation into CMAQ
Caltech Atmospheric
Chemistry Mechanism
Updated with α-Pinene,
β-Pinene & d-Limonene
Chemistry
H 2
SO 4
,HNO 3
NH 3
ISORROPIA Inorganic
Aerosol Module
H 2
O, H +
SOA
Precursors
POA
Model to Predict the
Multi-phase
Partitioning of Organics
SOA Output

Model
Domain
62 x 66 cells
36km resolution
21 vertical layers
Dates: August 3-4, 2004
August 1-2 spin-up
(ICARTT)
Meteorological fields:
MM-5
Emissions: 1999 NEI/BEIS3
Circles: IMPROVE
Star: AIRMAP
Triangles: SEARCH

Example Gas-Phase Results: AI*
160
Observation
120
CACM
CB4_1
O 3 Mixing Ratio (ppb)
80
40
0
2004-8-3 0:00 2004-8-3 12:00 2004-8-4 0:00 2004-8-4 12:00 2004-8-5 0:00
Time (UTC)
*Appledore Island, ME Chen et al., 2006

Aerosol-Phase Results: Domain
18
Concentration (µg/m 3 )
16
14
12
10
8
6
Measured
CACM/MPMPO
CB4/SORGAM
4
2
0
PM2.5 Sulfate Nitrate Ammonium EC OC
24-hour filter measurements; ions by IC, EC and OC by thermo-optical method
Chen et al., 2006

Aerosol-Phase Results: TF*
12.0
AMS measured
6.0
Measured OC (µg/m 3 )
10.0
8.0
6.0
4.0
2.0
CACM/MPMPO
CB4/SORGAM
4.0
2.0
Modeled OC (µg/m 3 )
0.0
8-3 0:00 8-3 12:00 8-4 0:00 8-4 12:00 8-5 0:00
Time (UTC)
0.0
Data from an Aerodyne Q-AMS (Cottrell et al., 2006, in prep.)
*Thompson Farm, NH
Chen et al., 2006

Domain-Wide Results: SOA
CACM/MPMPO
CB4/SORGAM
Chen et al.,
2006

Chen et al., 2006
Aqueous-Phase SOA

Other Recent Applications
•Study of dynamics of SOA in the SoCAB (Vutukuru et al.,
2006)
• SOA source apportionment in the SoCAB (Ying et al.,
2006; Kleeman et al., 2006)
• SOA study in southern France (high contribution of
diesel!; Tulet et al., 2006)
• Photochemical formation of CO in the eastern US and the
SoCAB (Griffin et al., 2006)
• Photochemical modeling of peroxy radicals for φ
calculations in New England (Griffin et al., 2006)

Hot Off the Press (1) – In-cloud
Chen et al.
poster here!

Hot Off the Press (2) - Alkanes
Jordan et al.
poster here!

Hot Off the Press (3) - Dynamics
Vutukuru et al.
AAAR poster

Example Strengths and
Weaknesses
Strengths
• Not specific to one set of chamber conditions
• Chemical and phase specificity
• Appropriate NO x
dependence (though not strong enough)
• A dynamic duo
Weaknesses
• Missing SOA sources (i.e., isoprene, sesquiterpenes,
organic-sulfate interactions including aldehydes, ?, etc.)
• Computationally expensive
• Specificity of emissions is somewhat burdensome
• POA and vapor pressure characterization
• Biased to SoCAB?

What’s Next?
• Missing chemistry
– Isoprene and sesquiterpenes
– Particle-phase/heterogeneous reactions (organicsulfate,
peroxides)
–Low-NO x chemistry
– Ammonia-acid interactions
– Cl-VOC chemistry for application to the MBL

Thanks to…
• My co-authors
• Laura Cottrell, Luke Ziemba, Pieter Beckman
(AMS data)
• Additional collaborators (Meteo France, UCD,
UCR)
• NOAA, EPA, NSF, & EPRI for funding
• The organizers