Biogenic Aerosol Studies

• Smog chamber studies >Aerosol yields (humidity, temperature, seed)>Product identification and quantification

(GCMS, LCMS, TDPBMS)>Mechanisms (use gas phase mechanisms to

explain products)

• Ambient measurements>GCMS of aldehydes and acids in filter

samples from forested areas>New particle formation in forests and surf

zones

• Modeling smog chambers and ambient

>Global biogenic SOA, nucleation, growth

Aerosol Yields from Biogenic Organics

Parent Yield

Acyclic Myrcene 7.6 – 12.7% Ocimene 2.4 – 6.0%Oxygenated Terpenes Linalool 1.9 – 7.3% Terpinene-4-ol 2.3 – 5.2%Bicyclic Olefins Δ3-Carene 2.3 – 10.9% α-Pinene 2.4 – 7.8% β-Pinene 4.2 – 13.0% Sabinene 4.7 – 10.6%Cycli c Diolefins Limonene 6.1 – 22.8% α & γ-Terpinene 3.4 – 12.7% Terpinolene 2.3 – 4.4%Sesquiterpenes β-Caryophyllene 17. 2 – 62.5% α-Humulene 20. 0 – 66.7%

OH and O3 Oxidation Patterns for Bicyclic Alkenes

Chamber Global AverageParent O3 OH O3 OH

Δ3-Carene 18. 0% 82.0% 16.2% 83.8%α-Pinene 41. 1% 58.9% 42.5% 57.5%β-Pinene 12. 6% 87.4% 8.0% 92.0%Sabinene 16. 9% 83.1% 25.2% 74.8%

Estimated Species Contributions to Global

Emissions

Species ContributionMonoterpenes α-Pinene 35% β-Pinene 23% Limonene 23% Myrcene 5% Sabinene 5% Δ3-Carene 4% Ocimene 2% Terpinolene 2% α & γ-Terpinene 1%ORVOC Terpenoi d Alcohols 9% C7-C10n-Carbonyls 7% Aromatics 6% Sequiterpenes 5% Terpenoi d Ketones 4% Highe r Olefins 1%

Monoterpenes = 127-147 Tg yr-1 ORVOC = 94-260 Tg yr-1

Biogenic Aerosol = 13-24 Tg yr-1

C C C C C CO O O

H H

H

H

H

H

H

H

H H

C C C C CO

H H

H

H

H

H

H

H

O

OO

CHCO

CH2CH2C

H2CH

H2cyclohexene

+ O3

. .

C C C C C CO O

H H

H

H

H

H

H

H

H

H O H

C C C C C CO O

H H

H

H

H

H

H

H

Hadipaldehyde 6-oxo-hexanoic acid

glutaraldehyde

*

CHCCH2

CH2CH2C

H

H2

Aldehydes

CCCCC O

HH

H

H

H

H

H

H

H

H

pentanal

5-oxo-pentanoic acid

CCCCC

O

OO

H

H

H

H

H

H

H H

Oxo-acids

glutaric acid

CCCCC

OO

OO

H

H

H

H

H

H

HH

adipic acid

CCCCCC

OO

OO

H

H

H

H

H

H

H

H

HH

Dicarboxylic Acids

Mechanisn of Cyclohexene + O3 Reaction

Biogenic Aerosol Studies: Future Needs

• Smog chamber studies >Aerosol yields (humidity, temperature)>Product identification and quantification

(labile and low volatility compounds), vapor pressures and activity coefficients (organic and aqueous solutions)>Mechanisms (include heterogeneous

reactions)

• Ambient measurements>Identification and quantification, and

biogenic marker compounds>New particle analysis