The Impact of Secondary The Impact of Secondary Organic Aerosol Organic Aerosol Derivatives of Isoprene on Derivatives of Isoprene on Cloud Formation and Cloud Formation and AlbedoAlbedo

Akua Asa-AwukuAkua Asa-AwukuEAS6410 Term Paper PresentationEAS6410 Term Paper Presentation

SummarySummary

• Motivation Motivation – Biogenic EmissionsBiogenic Emissions– Sources of IsopreneSources of Isoprene

• Sources of SOA from IsopreneSources of SOA from Isoprene• The impact of SOA’s on Cloud FormationThe impact of SOA’s on Cloud Formation• Cloud Formation and AlbedoCloud Formation and Albedo• Hydrological ImplicationsHydrological Implications

The Importance The Importance of Biogenic Emissionsof Biogenic Emissions

• Amazon has low levels of anthropogenic Amazon has low levels of anthropogenic emissionsemissions

• Isoprene emissions in US larger than Isoprene emissions in US larger than anthropogenic particulate matter anthropogenic particulate matter

• Eight Different Vegetation Types are major Eight Different Vegetation Types are major sources of Isoprenesources of Isoprene

Major Sources of NMHCMajor Sources of NMHC

SourceSource IsopreneIsoprene MonoterpeneMonoterpene ORVOCORVOC OVOCOVOC Total VOCTotal VOC

WoodsWoods 372372 9595 177177 177177 821821

CropsCrops 2424 66 4545 4545 120120

ShrubShrub 103103 2525 3333 3333 194194

OceanOcean 00 00 2.52.5 2.52.5 55

OtherOther 44 11 22 22 99

AllAll 503503 127127 260260 260260 11501150

Tg C yr-1

What is IsopreneWhat is Isoprene

• OlefinicOlefinic• Highly reactive Double BondsHighly reactive Double Bonds• Volatile Organic Compound (VOC)Volatile Organic Compound (VOC)• Non-Methane Hydrogen Carbon (NHMC)Non-Methane Hydrogen Carbon (NHMC)

Products of Isoprene Products of Isoprene PhotooxidationPhotooxidation

Derivatives of Derivatives of PhotoxidationPhotoxidation• Assumed to be extremely volatile (e.g Assumed to be extremely volatile (e.g

formaldehyde)formaldehyde)

• Assumed Most likely not to be SOA’s Assumed Most likely not to be SOA’s

• Two newly identified species hypothesized to Two newly identified species hypothesized to be SOA’s from photooxidation of isoprenebe SOA’s from photooxidation of isoprene

• Formation of SOA via acidic catalystsFormation of SOA via acidic catalysts

Data CollectionData Collection

• Data Samples collected from LBA-CLAIRE Data Samples collected from LBA-CLAIRE campaign July 25 -27 [Claeys, 2004]campaign July 25 -27 [Claeys, 2004]

• AssumptionsAssumptions– Very low Anthropogenic emissionsVery low Anthropogenic emissions– Tropics site of high photoxidationTropics site of high photoxidation

• Samples Subjected to GS-MSSamples Subjected to GS-MS

SOA from IsopreneSOA from Isoprene

• Gas Chromatography Gas Chromatography results that show results that show presence of a product presence of a product of isoprene photo-of isoprene photo-oxidationoxidation

• Similar 5 carbon Similar 5 carbon skeleton as that of skeleton as that of isopreneisoprene

SOA from IsopreneSOA from Isoprene• Proposed formation of Proposed formation of

the 2-methyltetrols from the 2-methyltetrols from isoprene by reaction isoprene by reaction with OH’Owith OH’O22 followed by followed by

self-and cross-reactions self-and cross-reactions with radicalswith radicals

• Intermediate 1,2, diols Intermediate 1,2, diols have been previously have been previously reported under low NOreported under low NOxx

conditions [Ruppert, conditions [Ruppert, 2000]2000]

Significance of (1) and Significance of (1) and (2)(2)• SOA’s have low yield from Isoprene SOA’s have low yield from Isoprene

photooxidationphotooxidation• However, large emissions of Isoprene, suggest However, large emissions of Isoprene, suggest

significant annual formation of SOA’ssignificant annual formation of SOA’s• Estimated 2 Tg per year of (1) and (2) in Estimated 2 Tg per year of (1) and (2) in

Amazon BasinAmazon Basin• IPCC estimates 8 to 40 Tg of biogenic SOA IPCC estimates 8 to 40 Tg of biogenic SOA

annuallyannually• Low Vapor Pressure and High HygroscopicityLow Vapor Pressure and High Hygroscopicity

SOA’s via Sulfuric Acid SOA’s via Sulfuric Acid CatalystsCatalysts• Urban and Rural Areas contain sufficient Urban and Rural Areas contain sufficient

amounts of background acidic catalystsamounts of background acidic catalysts

• Also significant emissions of Isoprene in these Also significant emissions of Isoprene in these regionsregions

• Limbeck explained that proposed pathway Limbeck explained that proposed pathway contribute to the explanation of HULIS contribute to the explanation of HULIS substances on continental Europesubstances on continental Europe

• Reaction Yield increases Reaction Yield increases with catalystwith catalyst

• Influence of ozone as Influence of ozone as competing oxidantcompeting oxidant

• Effect of Relative air Effect of Relative air HumidityHumidity

Short RecapShort Recap

• SOA’s from Isoprene ExistSOA’s from Isoprene Exist– Photooxidative products have low vapor pressuresPhotooxidative products have low vapor pressures– Humic-like substances generated from acidic Humic-like substances generated from acidic

catalystscatalysts

• All SOA’s from Isoprene can be considered to All SOA’s from Isoprene can be considered to be highly hydroscopicbe highly hydroscopic

Cloud FormationCloud Formation

• Kohler EquationKohler Equation– Kelvin EffectsKelvin Effects

• Strong functions of Strong functions of Surface TensionSurface Tension

• Humic-like aerosols Humic-like aerosols decrease decrease σσ

30

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pw

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w

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w

ws

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Decreasing Surface Decreasing Surface TensionTension

Kohler CurvesKohler Curves

Consequences of Consequences of SurfactantsSurfactants• Great Cloud Droplet NumberGreat Cloud Droplet Number

– 30% decrease in 30% decrease in σσ yields a 20% increase in droplet yields a 20% increase in droplet numbernumber

• Smaller cloud droplet RadiiSmaller cloud droplet Radii– Average 6% decrease in droplet sizeAverage 6% decrease in droplet size

• Significant Change in Cloud Properties (hence Significant Change in Cloud Properties (hence Albedo)Albedo)

Droplet Number and Droplet Number and AlbedoAlbedo

max

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extext drrnamQrb

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Albedo and Cloud Optical Albedo and Cloud Optical ThicknessThickness

SusceptiblitySusceptiblity

• defined as the sensitivity of cloud albedo in defined as the sensitivity of cloud albedo in comparison to cloud droplet number comparison to cloud droplet number concentration concentration

• ten percent increase in droplet number ten percent increase in droplet number concentration, leads to an increase of 0.75% in concentration, leads to an increase of 0.75% in albedo albedo

3

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Albedo and Cloud Optical Albedo and Cloud Optical ThicknessThickness

Isopre

ne Em

issi

ons

SOA Formation

Cloud Formation

Cloud Albedo

Precipitation/Water Stress

Surface Temperature

Hydrological CycleHydrological Cycle

ConclusionsConclusions

• SOA’s from Isoprene do existSOA’s from Isoprene do exist• Humic-like SOA’s decrease surface tensions Humic-like SOA’s decrease surface tensions

of pure water by 30% increase the droplet of pure water by 30% increase the droplet number concentration by 20% number concentration by 20%

• 20% increase in droplet number, correlates to a 20% increase in droplet number, correlates to a change in top of atmospheric cloud albedo of change in top of atmospheric cloud albedo of nearly 1% nearly 1%

• a global mean forcing of almost -1 Wma global mean forcing of almost -1 Wm -2 -2 due due to SOA’s from Isoprene to SOA’s from Isoprene

ReferencesReferences• BarthBarth, Mary et. al., Future Scientific Directions: Coupling between land ecosystems and the atmospheric hydrologic cycle through biogenic , Mary et. al., Future Scientific Directions: Coupling between land ecosystems and the atmospheric hydrologic cycle through biogenic

aerosol pathways., aerosol pathways., Bulletin of the American Meteorological Society, Bulletin of the American Meteorological Society, (submitted)(submitted)• BrasseurBrasseur, G., J. Orlando and G. Tyndall, Atmospheric Chemistry and Global Change, Oxford Univ. Press, New York, NY,1999 , G., J. Orlando and G. Tyndall, Atmospheric Chemistry and Global Change, Oxford Univ. Press, New York, NY,1999 • Claeys M, Graham B, Vas G, Wang W Vermeylen R, Pashaynshka V, Cafmeyer J, Guyon P, Andrae MO, Artaxo P, Maehunt W., Formation Claeys M, Graham B, Vas G, Wang W Vermeylen R, Pashaynshka V, Cafmeyer J, Guyon P, Andrae MO, Artaxo P, Maehunt W., Formation

of Secondary Organic Aerosols through photooxidation of Isoprene, of Secondary Organic Aerosols through photooxidation of Isoprene, ScienceScience, 202 (5661):1173-1176 Feb. 20. 2004, 202 (5661):1173-1176 Feb. 20. 2004• HelmigHelmig, Detlev .,Ben Balsley, Kenneth Davis, Laura R. Kcuck. Mike Jensen, John Bognar, Tyrrel Smith Jr., Rosaura Vasquez Arrieta, , Detlev .,Ben Balsley, Kenneth Davis, Laura R. Kcuck. Mike Jensen, John Bognar, Tyrrel Smith Jr., Rosaura Vasquez Arrieta,

Roldolfo Rodriguez, and John W. Berks., Vertical profiling and determination of landscape fluxes of biogenic non methange hydrocarbons Roldolfo Rodriguez, and John W. Berks., Vertical profiling and determination of landscape fluxes of biogenic non methange hydrocarbons with the planetary boundary layer in the Peruvian Amazon, with the planetary boundary layer in the Peruvian Amazon, J. Geophys. Res.¸J. Geophys. Res.¸103103 (D19): 25519-25532, 1998 (D19): 25519-25532, 1998

• DurieuxDurieux, L., L.A.T. Machado, H. Laurent, The impact of deforestation on cloud cover over the Amazon arc of deforestation, , L., L.A.T. Machado, H. Laurent, The impact of deforestation on cloud cover over the Amazon arc of deforestation, Remote Remote Sensing of Environ.Sensing of Environ., , 8686, 132-140, 2003., 132-140, 2003.

• FacchiniFacchini, M.., M. Mircea, S. Fuzzi, and R. J. Charlson, Cloud albedo enhancement by surface-active organic solutes in growing droplets, , M.., M. Mircea, S. Fuzzi, and R. J. Charlson, Cloud albedo enhancement by surface-active organic solutes in growing droplets, NatureNature, , 401401, 257-259. 1999, 257-259. 1999

• FallFall, R. and M.C. Wildermuth. Isoprene synthase: From biochemical mechanism to emission algorithm, , R. and M.C. Wildermuth. Isoprene synthase: From biochemical mechanism to emission algorithm, J. Geophys. Res.¸J. Geophys. Res.¸103103 (D19): 25599- (D19): 25599-25609, 1998.25609, 1998.

• GriffinGriffin, R.J., D.R. Cocker III, J.H. Seinfeld and D. Dabdub. Estimate of global atmospheric organic aerosol from oxidation of biogenic , R.J., D.R. Cocker III, J.H. Seinfeld and D. Dabdub. Estimate of global atmospheric organic aerosol from oxidation of biogenic hydrocarbons, hydrocarbons, Geophys. Res. Lett.Geophys. Res. Lett., , 2626 (17), 2721-2724, 1999. (17), 2721-2724, 1999.

• GuentherGuenther, A., C.N. Hewitt, D. Erickson, R. Fall, C. Geron, T. Graedel, P. Harley, L. Klinger, M. Lerdau, W.A. Mckay, T. Pierce, B. , A., C.N. Hewitt, D. Erickson, R. Fall, C. Geron, T. Graedel, P. Harley, L. Klinger, M. Lerdau, W.A. Mckay, T. Pierce, B. Scholes, R. Steinbrecher, R. Tallamraju, J. Taylor and P. Zimmerman, A global model of natural volatile organic compound emissionsScholes, R. Steinbrecher, R. Tallamraju, J. Taylor and P. Zimmerman, A global model of natural volatile organic compound emissions , , J.Geophys. ResJ.Geophys. Res. . 100100, 8873-8892,1995., 8873-8892,1995.

• GuentherGuenther, A., S. Archer, J. Greenberg, P. Harley, D. Helmig, L. Klinger, L. Vierling, M. Wildermuth, Biogenic hydrocarbon emissions and , A., S. Archer, J. Greenberg, P. Harley, D. Helmig, L. Klinger, L. Vierling, M. Wildermuth, Biogenic hydrocarbon emissions and landcover/climate change in a subtropical savanna, landcover/climate change in a subtropical savanna, Phys. Chem. Earth (B)Phys. Chem. Earth (B), , 2424, 659-667, 1999., 659-667, 1999.

• JangJang, M., and R. Kamens, Atmospheric secondary aerosol formation by heterogeneous reaction of aldehydes in the presence of a sulfuric , M., and R. Kamens, Atmospheric secondary aerosol formation by heterogeneous reaction of aldehydes in the presence of a sulfuric acid aerosol catalyst, acid aerosol catalyst, Environ. Sci. TechnolEnviron. Sci. Technol., ., 3535, 4758-4766, 2001., 4758-4766, 2001.

• KlingerKlinger, L.F., J. Greenberg, A. Guenther, G. Tyndall, P. Zimmerman, M. M’Bangui, J.M. Moutsambot, and D. Kenfck, Patterns in volatile , L.F., J. Greenberg, A. Guenther, G. Tyndall, P. Zimmerman, M. M’Bangui, J.M. Moutsambot, and D. Kenfck, Patterns in volatile organic compound emissions along a savanna rainforesst gradient in central Africa, organic compound emissions along a savanna rainforesst gradient in central Africa, J. Geophys. ResJ. Geophys. Res., ., 103103, 1443-1454, 1998., 1443-1454, 1998.

• LimbeckLimbeck, A., M. Kulmala, and H. Puxbuam, Secondary organic aerosol formation in the atmosphere via heterogeneous reaction of gaseous , A., M. Kulmala, and H. Puxbuam, Secondary organic aerosol formation in the atmosphere via heterogeneous reaction of gaseous isoprene on acidic particles, isoprene on acidic particles, Geophys. Res. Lett.,Geophys. Res. Lett., 3030 (19), 1996, 2003. doi: 10.1029/2003GL017738 (19), 1996, 2003. doi: 10.1029/2003GL017738

• OtterOtter, L.B., Guenther, A., Greenber, J., Seasonal and spatial vatirations in biogeneic hydrocarbon emissions from southern African , L.B., Guenther, A., Greenber, J., Seasonal and spatial vatirations in biogeneic hydrocarbon emissions from southern African savannas and woodlands, savannas and woodlands, Atmospheric Enirmonmet, Atmospheric Enirmonmet, 3636, 4265-4275, 2002., 4265-4275, 2002.

• PétronPétron, G., P. Harley, J. Greenberg, A. Guenther, Seasonal temperature variations influence isoprene emission, , G., P. Harley, J. Greenberg, A. Guenther, Seasonal temperature variations influence isoprene emission, Geophys. Res. LettGeophys. Res. Lett., ., 2828, , 1707-1710, 2000.1707-1710, 2000.

• PirjolaPirjola Liisa, Effects of the increased UV radiation and biogenic VOC emissions on Ultra fine sulphate aerosol Formation, Liisa, Effects of the increased UV radiation and biogenic VOC emissions on Ultra fine sulphate aerosol Formation, J.Aerosol Sci., J.Aerosol Sci., 3030, 3, 355-367, 1999., 3, 355-367, 1999.

• RobertsRoberts, G. C., M. O. Andreae, J. Zhou, P. Artaxo, Cloud condensation nuclei in the Amazon Basin: Marine conditions over a continent?, , G. C., M. O. Andreae, J. Zhou, P. Artaxo, Cloud condensation nuclei in the Amazon Basin: Marine conditions over a continent?, Geophys. Res. LettGeophys. Res. Lett., ., 2828, 2807-2810, 2001., 2807-2810, 2001.

• SeinfeldSeinfeld, J., and N. Pandis, , J., and N. Pandis, Atmospheric Chemistry and Physics: From air pollution to climate changeAtmospheric Chemistry and Physics: From air pollution to climate change , John Wiley & Sons, Inc., New York, , John Wiley & Sons, Inc., New York, NY 1998.NY 1998.