1

Global Budgets of Atmospheric Glyoxal and Global Budgets of Atmospheric Glyoxal and

Methylglyoxal and Implications for Formation of Methylglyoxal and Implications for Formation of

Secondary Organic AerosolsSecondary Organic Aerosols

Tzung-May Fu, Daniel J. JacobDepartment of Earth and Planetary Sciences

Harvard University

Folkard Wittrock, John P. Burrows, Mihalis VrekoussisInstitute of Environmental Physics and Remote Sensing

University of Bremen

Fu et al. [2007b] submittedThis work is supported by EPRI

CHOCHO

(glyoxal)

CH3C(O)CHO

(methylglyoxal)

US EPA November 8 2007

2

Organic Aerosols: Primary vs. SecondaryOrganic Aerosols: Primary vs. Secondary

Fossil fuel burning

Biomass burning

Direct emission

Primary Organic Aerosols (POA)

Secondary Organic Aerosols (SOA)

Isoprene Terpenes Aromatics

BIOGENIC SOURCES ANTHROPOGENIC SOURCES

Semi-volatile organic gases

Oxidation by OH, O3, NO3

Nucleation

Reversible partitioning on existing particles

FF: 45-80 TgC y-1

BB: 10-30 TgC y-1

3

ACE-Asia: OC aerosol measurements in the free troposphere ACE-Asia: OC aerosol measurements in the free troposphere

Mean ObservationsMean Simulation (GEOS-Chem global CTM)Observations+

Concentrations of OC in the FT were under-predicted by a factor of 10-100Current knowledge is missing a large SOA source

[Mader et al., 2002] [Huebert et al., 2003] [Maria et al., 2003]

(ACE-Asia aircraft campaign conducted off of Japan April/May 2001)

Heald et al. [2005], GRL

c/o Colette Heald

4

Where is the large missing SOA source?Where is the large missing SOA source?

Secondary Organic Aerosols (SOA)

Isoprene

400 Tg y-1

Terpenes Aromatics

BIOGENIC SOURCES ANTHROPOGENIC SOURCES

Semi-volatile organic gases

Oxidation by OH, O3, NO3

Volkamer et al. [2006]

SO

Ao

bs /

SO

Am

od

el

Nucleation

Reversible partitioning on existing particles

5

SOA formation by reactive uptake of dicarbonylsSOA formation by reactive uptake of dicarbonyls

glyoxalSOA

Isoprene (400 Tg y-1), monoterpenes, acetone, MBO, C2H4, C3H6

Photolysis

Oxidation

Deposition

Oligomers?

organic acids?

~ 2.9 hr

Acetone, C2H2, isoalkanes, alkenes, aromatics, glycolaldehyde, hydroxyacetone, primary emissions

methylglyoxal

OH, O3, NO3

~ 1.6 h

Our goal: build global model

Irreversible uptake?

Fu et al. [2007b]

6

What What are the irreversible processesare the irreversible processes in the AQ phase? in the AQ phase?

H2O

H2O

Oligomers

+ hydrates + H2O

Kalberer et al. [2004]Liggio et al. [2005] Hastings et al. [2005] Zhao et al. [2006]Loeffler et al. [2006]

1

Organic acids

+ OH ?

Ervens et al. [2004]Lim et al. [2005]Carlton et al. [2006, 2007]Warneck et al. [2005]Sorooshian et al. [2006]

2

Altieri et al. [2006]

3

H* ~ 105

H* ~ 103

7

First detailed global simulation of glyoxal and methylglyoxalFirst detailed global simulation of glyoxal and methylglyoxal

glyoxalSOA

Isoprene (400 Tg y-1), monoterpenes, acetone, MBO, C2H4, C3H6

Irreversible uptake

Photolysis

Oxidation

Deposition

lifetime ~ 2.9 hr

Acetone, C2H2, isoalkanes, alkenes, aromatics, glycolaldehyde, hydroxyacetone, primary emissions

methylglyoxal

OH, O3, NO3

lifetime ~ 1.6 hr

Built on GEOS-Chem global 3D CTM

Fu et al. [2007b]

8

New New isoprene oxidation adapted from MCM v3.1isoprene oxidation adapted from MCM v3.1

Isoprene + OH

0.046 Glyoxal + 0.16 Glycolaldehyde + 0.13 Methylglyoxal + 0.15 Hydroxyacetone

ON

O

O

O OH

OOH

O O O

OO

HO

OO

O

O

OH

Isoprene

C5 carbonylsHydroxy-

methylvinyl ketone Methylvinyl ketone Methacrolein

Glyoxal Glycolaldehyde Methylglyoxal Hydroxyacetone

Methyl-nitroxy butenal

25% 12% 37% 26%

18%33% 32%62%

29% 51% 24%39%

87%16%

45%52%

+ OH+ NO3

+ NO + NO

16%

84%

16%

84%

2%

andisomers

0.5%

Organicnitrates

Organicnitrates

Fu et al. [2007b]

9

Result: Sources of glyoxal and methylglyoxalResult: Sources of glyoxal and methylglyoxal

1 Isoprene is largest source for both glyoxal (47%) and methylglyoxal (79%).

2 Second largest sources C2H2 and acetone long lifetime dicarbonyl background

3 Glyoxal is more sensitive to non-biogenic emissions

Isoprene 110

Monoterpenes 3.5

Aromatics 1.4

Hydroxyacetone 3.6

Isoalkanes 3.7

>C2 alkenes 4.1

Methylglyoxal 5

Acetone 10

Glyoxal 45 Tg y-1 Methylglyoxal 140 Tg y-1

55%

20% 17%

8%

87%

5%

3%

5%BiogenicBiomass burningBiofuel useAnthropogenic

Isoprene 21

Acetylene8.9

Glyoxal 7.7 Ethene 2.5

Monoterpenes 1.8

Aromatics 2.0

Glycolaldehyde 0.54

MBO 0.35

(47%)

(79%)

Fu et al. [2007b]

10

Result: Photolysis is the dominant sink of dicarbonylsResult: Photolysis is the dominant sink of dicarbonyls

Glyoxal Methylglyoxal

PhotolysisOxidationSOA formationDry depositionWet deposition

2.9 hours 1.6 hoursLifetime:

1 Photolysis is the dominant sink for both dicarbonyls

2 SOA formation must compete against photolysis and oxidation

3 90% of SOA formation is in clouds

45 Tg y-1 140 Tg y-1Sink:

15 Gg 25 GgBurden:

Fu et al. [2007b]

11

Simulated global concentrations of glyoxalSimulated global concentrations of glyoxal

Isoprene 21

C2H2 8.9

Glyoxal 7.7 C2H4 2.5

Monoterpenes 1.8

Aromatics 2.0

Glycolaldehyde 0.54

MBO 0.35

2 Northern mid-latitude summertime model glyoxal ~ 10-100 ppt

1 Biomass burning: highest surface concentration

3 Acetylene: hemispheric background and anthropogenic outflow

Fu et al. [2007b]

12

Simulated global concentrations of methylglyoxalSimulated global concentrations of methylglyoxal

Isoprene 110

Monoterpenes 3.5

Aromatics 1.4

Hydroxyacetone 3.6

Isoalkanes 3.7

>C2 alkenes 4.1

Methylglyoxal 5

Acetone 10 2 Northern mid-latitude summertime model methylglyoxal ~ 20-150 ppt, w/ stronger biogenic pattern

1 Biomass burning: highest surface concentration

3 Acetone: global background and anthropogenic outflow

Fu et al. [2007b]

13

Simulated dicarbonyl concentrations are Simulated dicarbonyl concentrations are consistent with available in situ measurementsconsistent with available in situ measurements

Glyoxal Methylglyoxal

Northern mid-latitudes (summer)Marine boundary layer

Free troposphere

1 Northern mid-latitudes summertime dicarbonyl concentrations consistent with measurements

2 Marine boundary layer model underestimates dicarbonyls?Fu et al. [2007b]

14

Simulated glyoxal pattern consistent w/ satellite over landSimulated glyoxal pattern consistent w/ satellite over land

Wittrock et al. [2006a,b]

Overall error ~ 4 x 1014 molec cm-2

Over land: simulated glyoxal column pattern agrees well with satellite observations, but model concentrations are 50% lower

Satellite product has error ~ 4 x 1014 molec cm-2 and issues with clouds [Wittrock et al., 2006b]

Fu et al. [2007b]

SCIAMACHY GEOS-Chem

1~3.5 x 1014 molec cm-2 0.5~2 x 1014 molec cm-2

15

Is there a large unknown marine source of glyoxal?Is there a large unknown marine source of glyoxal?

Wittrock et al. [2006a]

Over tropical ocean: satellite retrieve high glyoxal column

interference by chlorophyll?

unknown marine emissions or precursors?

Fu et al. [2007b]

SCIAMACHY

MODIS chlorophyll 2006

GEOS-Chem

16

Terpenes Isoprene Aromatics Glyoxal +Methylglyoxal

An

nu

al S

OA

so

urc

e [T

g C

y-1]

Dicarbonyls produce large amounts of SOA!Dicarbonyls produce large amounts of SOA!

6.7

9.0

11

1.8

Reversible partitioning Irreversible uptake by aerosol (10%) and clouds (90%)

SOA production via irreversible uptake of dicarbonyls comparable

to SOA production from reversible partitioning

Glyoxal 2.6

Methyl-gyloxal 8.0

AnthropogenicBiofuel useBiomass burningBiogenic

Fu et al. [2007b]

20%

17

Are the reversible / irreversible production of SOA Are the reversible / irreversible production of SOA from isoprene oxidation products additive?from isoprene oxidation products additive?

Kroll et al. [2006], Surrat et al. [2006]

Isoprene

Methacrolein

Methyl vinyl ketone

SOA from reversible partitioningX

It is unclear, BUT

Experiments conducted at RH < 10% no aqueous reaction

(glyoxal and methylglyoxal)

(methylglyoxal)

18

Major findings : Global budgets of dicarbonyls Major findings : Global budgets of dicarbonyls and their SOA productionand their SOA production

OH, NO3, O3

CHOCHO+

CH3COCHOIrreversible uptake

SOA production from dicarbonyls 11 Tg C y-1

Current simulated SOA sources from biogenic terpenes (9 Tg C y-1), isoprene (7 Tg C y-1) and aromatics are too small!

Isoprene, monoterpenes, acetone, MBO, C2H4, C3H6

Acetone, C2H2, isoalkanes, alkenes, aromatics, glycolaldehyde, hydroxyacetone, primary emissions

Isoprene is the largest source of dicarbonyls

20% of SOA produced via dicarbonyls are from non-biogenic emissions, especially in FT

Fu et al. [2007b]

19

Contribution of dicarbonyl SOA in U.S.Contribution of dicarbonyl SOA in U.S.

Aircraft measurements during ICARTT (summer 2004)

Water Soluble Organic Carbon by Rodney Weber at Georgia Tech

Samples influenced by biomass burning removed

Observed WSOC

Modelw/ dicarbonyl

SOA

Modelw/o dicarbonyl

SOA

Observed WSOCModel w/ dicarbonyl SOAModel w/o dicarbonyl SOA

Alt

itu

de

[km

]

WSOC [g C m-3 STP][g C m-3 STP]

20

Observed WSOC

Model WSOC including SOA from dicarbonyl

Model WSOC without SOA from dicarbonyls

Correlation coefficient (r)

ICARTT WP3 measurements in FT (2 to 6 km), without biomass burning samples

WSOC correlation with other measured tracersWSOC correlation with other measured tracers

Dicarbonyl SOA

captures a lot of the observed variation

correlates with sulfate (aqueous processes) and toluene (anthropogenic precursors)0 0.1 0.2 0.3 0.4 0.5

OBS WSOC

CO

Sulfate

Methanol

Ammonium

Benzene

Toluene

PAN

Acetylene

Methyl nitrate

Ethyl nitrate

Isopropyl nitrate

21

WSOC production in cloud – need regional modelWSOC production in cloud – need regional model

Measurements on Twin Otter during ICARTT (summer 2004)Sorooshian et al. [2006]

SO4OxalateNH4 NO3

Power plant plume in cloudsMeasured oxalate consistent with toluene being precursor

SO4 [nmol m-3]

Oxa

late

[

nm

ol

m-3]

22

Using suite of satellite observations to diagnose Using suite of satellite observations to diagnose regional pollutant emission and chemistryregional pollutant emission and chemistry

NO2 June 2005 Glyoxal June 2005 SO2 June 2005

c/o KNMI c/o KNMIc/o T. Kurosu

July 25

2005

July 26

2005

July 27

2005

Glyoxal HCHO NO2Volkamer et al. [2006]