improved prediction of in-cloud biogenic soa
TRANSCRIPT
Improved Prediction of In-Cloud Biogenic SOA: Experiments and CMAQ Model Refinements
Barbara Turpin, PISybil Seitzinger, Co-I
Rutgers UniversityNew Brunswick, NJ
SOA –
a major fine particle constituent
Zhang GRL 2007
organicsulfateammoniumnitrate
OOAHOA
Aerosol Mass Spectrometer Data
CondensationEvaporation
VolatileOrganicCompound>C7
Oxidation (+OH, NO3 , O3 )
Semi-volatile Products
pre-existing particlePartitioning into OM
SOAVolatileproducts
Gas-phaseReactions
Pankow 1994, AE
Odum 1996, ES&T
Traditional “smog chamber”
SOA
Precursors must be large (>C7) to produce high yields because partitioning depends on product vapor pressure
Dept of Environmental SciencesWhile important, fails to explain:
•Predictive models capture organic aerosol poorly (Hallquist ACP 2009)
•Atmospheric O/C > smog chamber O/C (Aiken EST 2008)
atmos. HOA = 0.06 – 0.1atmos. OOA-SV = 0.5 – 0.6atmos. OOA-LV = 0.8 – 1.0
sm. chamber SOA = 0.3 – 0.5
•Liquid water may be more accessible than OMe.g., high humidities of eastern US
Cloud evaporation
SOA
·OH
·OH
·OH
NOx
·OH
·OH
·OH
NOx
NOx, alkenes, aromatics
O
OO
O
·OH O3
·OH
Isoprene
In Clouds and Fogs:Hypothesis: Blando and Turpin, AtmosEnv, 2000
Gelencser and Varga, ACP, 2005
Organic gases are oxidized forming water-soluble compounds.
These partition into cloud droplets and react further (e.g., by ·OH).
Cloud droplets evaporate, lower volatility products remain, forming SOA.
and in Aerosol Water:Hypothesis: Carlton AtmosEnv, 2007
Volkamer GRL, 2007
Water-soluble gases partition into aerosol water and react.
Lower volatility products remain, forming SOA.
SOA through Aqueous Chemistry: Partitioning driven by water solubility
isoprene
Wet aerosol
SOAglyoxal OH
PartitioningOH
oligomerization
Aerosol water(LWC)
Organic/inorganic
constituents
Partitioning
low volatilityproducts
OH
oligomerization
Clouddroplet
SOACloud Droplet Evaporation
Volatile butHighly water soluble
~M
~0.1- 10M
glyoxal uptake
glyoxal evaporation
Implications•organic PM loading •vertical distribution•different precursors
(Volkamer ACP, 2009)
•product O/C
1
Carlton GRL 2006, AE 2007; Altieri EST 2006, AE 2008; Perri AE 2009
Previous research:Major products of OH radical oxidation verified (≥1mM)
Phase transfersRxs with •OH
Aqueous phase
ISOPRENE + oxidants (·OH, O3, NO3)
HOCH2CHO CHOCHO CH3COCHO(glycolaldehyde) (glyoxal) (methylglyoxal)
HOCH2CH(OH)2 (OH)2CHCH(OH)2 CH3COCH(OH)2
HOCH2COOH CH3COCOOH(glycolic acid) (pyruvic acid)
(OH)2CHCOOH CH3COOH(glyoxylic acid) (acetic acid)
HOOCCOOH CH2(OH)2(oxalic acid) (formaldehyde - hydrated)
CO2 HCOOH(formic acid)
Gas phase
(hydrated glyoxal)
Demonstrate kinetic feasibility of SOA formation through cloud processing using (mostly) measured rate const.
Rate constants available from cloud and wastewater literature Herrmann, Monod, Stefan and Bolton
Questions:How does precursor concentration matter?How do high molecular weight products form?Can the chemical model reproduce experiments?How do anthropogenic emissions impact biogenic
“aqueous” SOA formation?
Warneck AE 2003; Ervens JGR 2004; Lim EST 2005
Previous research:Cloud chemistry/parcel model predictions
Overall Goal:Improve the simulation of secondary organic aerosol (SOA)
formation through atmospheric aqueous chemistry
Approach:• Conduct aqueous experiments at cloud concentrations and
HNO3 (glyoxal/ methylglyoxal + OH)
• Validate/refine aqueous chemical mechanisms; update the cloud chemistry model
• Add in-cloud SOA formation to CMAQ
• Begin to explore the magnitude of in-cloud SOA formation and role of NOx /HNO3 in SOA formation from isoprene through cloud processing
Improved Prediction of In-Cloud Biogenic SOA
Roles of NOx in Aqueous SOA from Isoprene:
1. Gas phase formation of atmospheric oxidants
2. Gas phase formation of water soluble carbonyls
3. Aqueous NO3 catalysis, organic nitrogen products?
Project Experiments
Modeling (collaborators)
This Project
On-line ESI MS; IC-ESI-MS; FT-ICR MS; ESI-MS-MS, UV or IC for organic acids, DOC for mass balance, H2 O2
Experiments 10 ‐
3000 M ORG H2
O2
+hν ∙OH (10‐12 M)2‐5 pH± HNO3
, NH4
ORG: glyoxal, methylglyoxal
Controls ORG+Prod+UV
± HNO3
, NH4
ORG+Prod+H2
O2
± HNO3
, NH4UV+H2
O2
Aqueous-Phase Reactions with Product Analysis
Goal: Validate/Refine Aqueous Chemistry Model
Precursor/products modeled in reaction vessel: C
once
ntra
tion
(M
)
Time (min)
Methylglyoxal + OH radical
methylglyoxal
pyruvic acid
acetic acid
glyoxylic acid, formic acid, formaldehyde
oxalic acid
Methylglyoxal
Acetic acid
Glyoxylicacid
Pyruvic acid
formic acid
H2O2
·OH
Oxalic acid
Formaldehyde
Tan AE, 2010
Dilute aqueous chemistry model reproduces oxalic, pyruvic acid and total organic carbon at 30 M
0 50 100 150 2000
5
10
15
20
25
30
35
0 50 100 150 2000
50
100
150
200
250
0 50 100 150 2000
200
400
600
800
1000
(a)
30 M glyoxal
(b)
300 M glyoxal
Oxa
lic A
cid
Con
cent
ratio
n (
M)
Model Prediction No H2SO4
280 M H2SO4
840 M H2SO4
(c)
3000 M glyoxal
Time (min)
0
2
4
6
8
10
0
20
40
60
80
100
0 100 200 300 4000
100
200
300
400
without H2SO4
280 M H2SO4
840 M H2SO4
model prediction
Oxa
lic a
cid
(M
)
Time (min)
30 M methylglyoxal + 0.15 mM H2O2
300 M methylglyoxal+ 1.5 mM H2O2
MethylglyoxalGlyoxal
Cloud relevant ~30 M
300 M
3000 M
Oxa
lic A
cid
(M
)
Oxa
lic A
cid
(M
)
Time (min) Time (min)
Tan EST 2009; AE 2010
Methylglyoxal (3000 M) + OH radical (10-12 M)
Oxalate formation verified with IC ESI-MSMethylglyoxal
Acetic acid
Glyoxylic acid
Pyruvic acid
formic acid
H2 O2
·OH
Oxalic acid
Formaldehyde
Oxalic acid (pk I, m/z- 89)
Pyruvic acid
40
30
20
10
00 5 10
Abu
ndan
ce
93
J
I
H
contaminant 1
CA+B
JI
H
contaminant 1
C
117
89
11997
92
87
14175 A+BConductivity (S)
Tim
e (m
in)
1000
2000
3000
1x105
2x105
2000
4000
1x104
2x104
1x105
2x105
0 100 200 300
3x104
6x104
m/z-
IC ESI-MS
Acetic acid
Oxalic acid
Tim
e (m
in)
m/z-
(180 min)
Tan AE, 2010
40
35
30
25
20
15
10
5
00 10 20 30 40 50
157143131
8789
89
191
C
A
unknown 1
C
Aunknown 1
Conductivity (S)
Tim
e (m
in)
0
2x104
4x104
6x104
8x104
0
1x105
2x105
3x105
abun
danc
e
0 100 200 3000
2x104
4x104
6x104
8x104
m/z-
40
35
30
25
20
15
10
5
00 20 40 60 80
113 199
191B
A+B
A
Conductivity (S)
Tim
e (m
in)
0 100 200 3000
2x104
4x104
6x104
m/z-
Methylglyoxal (3000 M) + UV
Methylglyoxal experiment with IC ESI-MS
IC ESI-MS IC ESI-MS
Methylglyoxal (3000 M) + H2 O2
Acetic acidPyruvic acid
Oxalic acid
Tim
e (m
in)
m/z-
m/z-
Oxalic acid forms only in the presence of OH radical
No oxalic acid forms in control experimentsNo oxalic acid
forms in control experiments
(180 min)
Tan AE, 2010
Little effect on oxalate (slighly faster decay with nitric acid)No change in nitrate or sulfate throughout the reactionNo discernable change in IC ESI-MSMight still form enough organic-N to observe by FT-ICR MS
Addition of HNO3
(1.7 mM) or (NH4
)2
SO4
(0.84 mM)to glyoxal (1 mM) and OH radical (10‐12
M)
Kirkland, in prep
0 10 20 30 40 50 600.3
0.4
0.5
0.6
0.7
0.8
0.0 0.1 0.2 0.3 0.40.3
0.4
0.5
0.6
0.7
0.8
0.0 0.1 0.2 0.3 0.43
4
5
6
7
8
9
10
0 10 20 30 40 50 60
Y c [%
]
3
4
5
6
7
8
9
10
[min h-1]
[min h-1]
Y c [%
]
Y c [%
]Y c
[%]
LWCav [g m-3]
LWCav
[g m-3]
(a) VOC/NOx = 5 r2 = 0.72
(b) VOC/NOx = 5 r2 = 0.45
(d) VOC/NOx = 100 r2 = 0.55
(c) VOC/NOx = 100 r2 = 0.69
0.1 1 10 10005
1015202530354045
Trajectory 1Trajectory 2Trajectory 3
VOC/NOx
Y c [%
]
Impact of NOx on SOA from isoprene through cloud proc.
Note: higher SOA yields with higher NOx because more gas phase production of water soluble carbonyls
Ervens GRL 2008Ervens ACP 2010
Yield (%) = mass C in SOAmass isoprene C
Feingold microphys. cloud model
•multiple cycles •stratocumulus•partitioning of wsoc•gas+aq chem•Ervens aq chem •altered Gly, PA chem
Cloud contact time
VOC/NOx
Yiel
d c(%
)
Yiel
d c(%
)
Yiel
d c(%
)
Model deviates from measurements at higher concentrations – what happens in wet aerosols?
0 50 100 150 2000
5
10
15
20
25
30
35
0 50 100 150 2000
50
100
150
200
250
0 50 100 150 2000
200
400
600
800
1000
(a)
30 M glyoxal
(b)
300 M glyoxal
Oxa
lic A
cid
Con
cent
ratio
n (
M)
Model Prediction No H2SO4
280 M H2SO4
840 M H2SO4
(c)
3000 M glyoxal
Time (min)
0
2
4
6
8
10
0
20
40
60
80
100
0 100 200 300 4000
100
200
300
400
without H2SO4
280 M H2SO4
840 M H2SO4
model prediction
Oxa
lic a
cid
(M
)
Time (min)
30 M methylglyoxal + 0.15 mM H2O2
300 M methylglyoxal+ 1.5 mM H2O2
MethylglyoxalGlyoxal
Cloud relevant ~30 M
Aerosol relevant ~1-10 M
Oxa
lic A
cid
(M
)
Oxa
lic A
cid
(M
)
Time (min) Time (min)
300 M
3000 M
(a) ESI-MS 69 min. neg mode
(b) ESI FT-ICR MS69 min. neg mode
Peak Location300 350 400 450 500
Peak
Hei
ght
0
20
40
m/z50 100 150 200 250 300 350 400 450 500 550 6001000
Ion
abun
danc
e
0
2000
4000
6000
8000
10000
C14H17O12377.070380
C17H13O11393.044360
C16H19O14435.075940
C13H15O12363.054800
C23H13O20465.177920
C12H13O20476.99925
m/z0 100 200 300
Ion
abun
danc
e
0100000200000300000400000500000
73
87
89
PA
GA
•High MW products
•O/C ~ 1
•Not seen in std mix (not ESI artifact)
•Not in controls (·OH involved)
Ultra high resolution FT-ICR MS (9.4 T) provides exact elemental comp. > m/z 300
OA
Methylglyoxal (1mM) + ∙OH
*Electrospray ionization Fourier transform-ion cyclotron resonance mass spectrometry
Altieri AE 2008
40
35
30
25
20
15
10
5
00 10 20
Abu
ndan
ce
unknown 2
221 263249
235
89
119177
133177
175161
87
75
177
103
117
177
131
unknown 3
I
H
F
E
unknown 2
A+B+C
unknown 3
IH
FE
A+B+C
Conductivity (S)
Tim
e (m
in)
02x104
4x104
0
3x105
6x105
03x105
6x105
05x104
1x105
0
1x104
2x104
01x105
2x105
0 100 200 3000
3x104
6x104
m/z-
Chemistry at Higher Concentrations―Methylglyoxal
Higher-MW ions
Oxalic acid (peak I, m/z- 89)
RT of Succinic acid (m/z- 117)
RT of Malonic acid (m/z- 103)
Formation of higher C# products
Tan AE, 2010
0 100 200 300 4000
100
200
300
400
Oxa
lic a
cid
(M
)
Time (min)
Chemistry at Higher Concentrations―Methylglyoxal
Larger acids are important products at higher concentrations.
Formation of higher C# products suggests radical-
radical reactions0
100
200
300
peak F quantified as malonic acid
peak E quantified as succinic acid
Con
cent
ratio
n (
M)
without H2SO4
280 M H2SO4
840 M H2SO4
0 100 200 300 4000
50
100
150
200
Con
cent
ratio
n (
M)
Time (min)(Tan AE 2010)
OO 2 H2O OHHO
OHHOH+
OH
H2O
OHHO
OHHO
O2OHHO
OHHO
OHO
OHHO
OO
RO2
OHHO
OHHOO
HO
HO+ O
OH
OH
O2 HO2
O
HO
glyoxal(hydrated)
1 glyoxylic acid(hydrated)
2 formic acid
+ HO2
OHO
OHHO
O2OHO
OHHOOO
OO
OHHO3 oxalic acid
+ HO2
OHO
OHHOO
OHO
OHHOO +
OO
OHO
O
HO+ CO2
CO2
CO2
glyoxal
decomposition
+ O2
+ O2
OH
H2O
RO2decomposition
decomposition
decomposition
O2 HO2
OH
H2O
O2 HO2
decomposition
R*1
R*3
R*2
R*4
R*4
4(hydrated)
4
4
4
4(hydrated)
Aqueous Mechanism - Glyoxal Y Lim ACPD 2010
Y Lim ACPD 2010
Mass o
xalat
e
formed
per m
ass
glyox
al rea
cted
Mass high MW
products formed
per mass glyoxal
reacted
Model produces oxalate at cloud‐relevant concentrations and oligomers at aerosol‐relevant
glyoxal concentrations (OH radical = 10‐12
M)
Cloud wet aerosol
Chemistry in wet aerosols –
complex
•Photolysis and photooxidation reactions
•Reactions of organics with ammonium and amines to form organic-nitrogen compounds
•Reactions of organics with sulfate to form organic-sulfates
•Acid and ammonium catalyzed oligomerization
Investigators include:Anastasio, Claeys, Cordova, de Haan, Flagan, Galloway, Grgic, Guzman, Hoffmann, Jimenez, Keutsch, Liu, Maenhaut, Michaud, McNeill, Monod, Noziere, Sareen, Seinfeld, Shapiro, Sun, Tolbert, Volkamer, Wortham, Yasmeen, Zhang
SOA formation from glyoxal
increases with LWC
SOA formation faster with OH radical (light)
Volkamer ACP 2009
(Seed: ammonium bisulfate + humic acid salt; acetylene; hydrogen peroxide; light/dark) Dark reaction
(Carlton EST 2008)
Improved model
performance;
ICARTT
SOA through cloud processing now in CMAQ (yields)
“Aqueous” comparable in magnitude to “smog chamber” SOA(Chen ACP 2007; Fu JGR 2008; Carlton EST 2008; Fu Atmos.Environ. 2009)
Dept of Environmental SciencesOverview
(Lim et al., ACPD 2010)
•Predictive models capture organic aerosol poorlyaqueous SOA precursors different (Volkamer ACP 2009)improved with “aqueous” SOA (Carlton EST 2008)
•Atmospheric O/C > smog chamber O/C (Aiken EST 2008)
atmos. OOA-LV = 0.8 – 1.0 atmos. OOA-SV = 0.5 – 0.6sm. chamber SOA = 0.3 – 0.5aqueous SOA = 1-2
•Sometimes liquid water is more accessible than OM e.g., high humidities of eastern US
•Atlanta - SOA is correlated with liquid waterAtlanta (Hennigan GRL 2008; Hennigan ACP 2009)
•Anthropogenic pollutants generate biogenic SOAhigher yields for aqueous SOA from isoprene at high NOx (Ervens GRL 2008)
Secondary Organic Aerosol
Past/present Students, PostdocsHo Jin LimKatie AltieriYi TanMark PerriYong Bin LimDiana Ortiz SupportMary Moore U.S. EPA – STARAnjuli RamosPhyllis KuoJeff Kirkland
Acknowledgements