Biosphere Atmosphere Exchange

1) Directly emitted GHGs

CO2, CH4, N2O2) Chemical sources of GHGs and SOA

BVOCs CO CO2

BVOC aerosol

3) Effects of biogenic emissions on O3, OH and NO3

NOx

BVOC H2CO

BVOC + O3 OH

•What are the magnitudes of these sources?

•How are they distributed, in time and space?

•How do they impact atmospheric chemistry & global greenhouse gases?

•What are the emissions of “natural systems”?

•What are the effects of management, e.g. fertilizer, timber forests?

Molecules:

CO2, CO, CH4, NO2, O3, H2CO, glyoxal

Aerosol properties

Satellite observations that will contribute

SOURCES OF ATMOSPHERIC METHANE

ANIMALS90

LANDFILLS50

GAS60

COAL40RICE

85

TERMITES25

WETLANDS180

BIOMASSBURNING20

GLOBAL METHANESOURCES (Tg CH4 yr-1)

Diffuse human-caused sources account for 365 in a total of 550 (70%). Agriculture accounts for 175 (30%)

1760 1780 1800 1820 1840 1860

020

0040

0060

0080

0010

000

Methane (ppb)

Alt

(m)

CH4 over North Dakota

Summer, 2000

(COBRA)

Growth of CH4 slowed dramatically after 1991. Will increases resume?

The vertical gradient over the Midwest is comparable to the gradient in the Amazon.

S. Del Grosso, S. Ogle and B. Parton, in reviewTotal ~ 0.6 TgN/yr, 15% of global total

PRESENT-DAY GLOBAL BUDGET PRESENT-DAY GLOBAL BUDGET OF ATMOSPHERIC NOF ATMOSPHERIC N22O O

12 (9 – 16)SINK (Tg N yr-1)

Photolysis and oxidation in stratosphere

4 (3 – 5)ACCUMULATION (Tg N yr-1)

1 (1 – 2)Industrial

2 (1 – 3)Livestock

4 (1 – 15)Agricultural soils

8 (2 – 21)Anthropogenic

2 (1 – 4)Temperate soils

4 (3 – 6)Tropical soils

3 (1 - 5)Ocean

10 (5 – 16)Natural

18 (7 – 37)SOURCES (Tg N yr-1)

Although a closed budget can be constructed, uncertainties in sources are large! (N2O atm mass = 5.13 1018 kg x 3.1 10-7 x28/29 = 1535 Tg )

IPCC[2001]

2) Chemical Sources of GHGs and 2) Chemical Sources of GHGs and aerosolaerosol(BVOCs, (BVOCs, 1000’s of compounds)1000’s of compounds)

Isoprene (CIsoprene (C55HH88))

Monoterpenes (CMonoterpenes (C1010HH1616))

Oxygenated VOCOxygenated VOC

Sesquiterpenes (CSesquiterpenes (C1515HH2424))

OH O

CHOOH

Amount Known

C.Warneke et al., 2002

Agriculture produces a wide variety of highly reactive hydrocarbons, often in large quantities.

Concentrations and fluxes of oxygenated HCs over an alfalfa field in Colorado.

Methanol

Acetaldehyde

Acetone

Methanol

Acetaldehyde

Acetone

Mixi

ng ra

tio (p

pb)

Flux

(mg

m-2 h

r-1)

Secondary Organic Aerosol (SOA) Secondary Organic Aerosol (SOA) Production from biogenic VOC emissionsProduction from biogenic VOC emissions

IsopreneMono- and SesquiterpeneEmissions

Oxidation Reactions(OH, O3, NO3)

Nucleation (oxidation products)

Growth

Condensation on pre-existing aerosol

Nucleation(unlikely)

Graphic from M. Lunden

Nga et al., ES&T, 2006

Goldstein and Galbally, ES&T 2007

Atmospheric VOC

SecondaryOrganic Aerosol

510-910 SOA Formation

310-720 Oxidation to CO/CO2``

175-375 Dry + Wet Deposition

130-270 Dry + Wet Deposition

~1300 Biogenic + Anthropogenic Global VOC Emissions

Units Tg C yr-1

50-200 Oxidation to VOC/CO/CO2

3) O3) O33, OH, NO, OH, NO33

Biogenic NOBiogenic NOxx emissions: OH, NO emissions: OH, NO33,, and Oand O33

BVOC BVOC HH22CO, aerosol oxidation?CO, aerosol oxidation?

OO33 + BVOC + BVOC OH + products OH + products

Cohen Group Meeting 31 August 2005

Partitioning of Global NOx Sources

SourceSource Tg N year Tg N year -1-1

Fuel ConsumptionFuel Consumption 2525

Biomass BurningBiomass Burning 66

Soil EmissionSoil Emission 99

LightningLightning ~10~10

TotalTotal ~50~50

Based on Jaegle et al. Faraday Discussions, 130, 407-423, DOI: 10.1039/b502128f, 2005

Cohen Group Meeting 31 August 2005

SCIAMACHY Soil NOx Observations - MontanaBertram et al GRL 2005

Cohen Group Meeting 31 August 2005

Local Tuning of Y&L Soil NOx Model

0

1

2

3

4b-

cary

ophy

llene

a-hu

mul

ene

long

ifol

ene

limon

ene

myr

cene

met

hyl c

havi

col

3-ca

rene

arom

aden

dren

e

a-pi

nene

terp

inol

ene

b-pi

nene

g-te

rpin

ene

a-te

rpin

ene

verb

enon

e

linal

ool

isop

rene

aerosol formaldehydeacetaldehyde formic acidacetone acetic acidunidentified m/ z other 1other 2

OO

H O

Lee et al., JGR, 2006.

Terpenes and isoprene are source of H2CO

Terpenes + OTerpenes + O33 OH + OxProducts OH + OxProducts

Growing body of evidence that BVOC Growing body of evidence that BVOC emissions are a strong source of OH both emissions are a strong source of OH both within the forest canopy and above.within the forest canopy and above.

Goldstein et al. GRL and ACPGoldstein et al. GRL and ACPChemical OChemical O33 deposition depositionRapid Production of secondary VOC products Rapid Production of secondary VOC products

Helmig et al. ES&THelmig et al. ES&TSesquiterpene emissions are 20% of monoterpene emissions for Sesquiterpene emissions are 20% of monoterpene emissions for several pine speciesseveral pine species

Brune et al. JGR/ScBrune et al. JGR/ScieiencenceExcess OH observed in regions of high biogenic emissions including ground sites in Excess OH observed in regions of high biogenic emissions including ground sites in Alabama, Nashville and Michigan and from the aircraft. Alabama, Nashville and Michigan and from the aircraft.

Higher OH reactivity than accounted for by measured VOHigher OH reactivity than accounted for by measured VOC associated with biogenicsC associated with biogenics

Cohen Cohen ACPACPHNOHNO33 flux over a pine forest is upward implying 5-10 times more OH in the flux over a pine forest is upward implying 5-10 times more OH in the forest canopy than aboveforest canopy than above

MarMartinez (MPI-Mainz)tinez (MPI-Mainz)Excess OH correlated with isoprene over SurinamExcess OH correlated with isoprene over Surinam

Kulmala et al.Kulmala et al.Evidence in modeling and aerosol over forest in FinlandEvidence in modeling and aerosol over forest in Finland

Ren, Brune, et al.Ren, Brune, et al.

10 100 1000 1

3

5

7

9

Isoprene (pptv)

OH

ob

s/m

od

0 6 12 18 24

0 6 12 18 240.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Time of Day

Summer (June-August) Blodgett Forest

Farmer and Cohen, in preparation

flux (ppb m s-1)

NO2∑PNs ∑ANs HNO3

mixing ratio (ppb)

0 6 12 18

-0.01

0.00

0.01

0 6 12 18

0 6 12 18

0 6 12 18 24

-0.01

0.00

0.01

HN

O3

flux

(ppb

m s

-1)

Summer—HNO3 flux

Focus on noon

Summer—HNO3 flux

Calculated based on deposition velocity

Based on flux-gradient relationships

0.46 0.48 0.505

6

7

8

9

10

11

12

Hei

gh

t (m

)

HNO3 (ppb)

Chemistry

OH+NO2HNO3 OHcanopy = 3.1 x 107 molec∙cm-3

background OH ~5 x 106 molec∙cm-3

NO2 = 300ppt

Solve for OH needed to produce HNO3 that is identified as chemical.

OH = 3.1 x 107 molec∙cm-3

Residence time in the canopy is about 600 sec

-Di Carlo et al. [2004]Measured– Calculated OH LossInferred unmeasured reactive BVOCs.

-Kulmala et al., [2000] Aerosol growth Hyytiala Forest, FinlandFrom BVOC?

-Ciccioli et al. [1999] sesquiterpenes in leaf enclosures were not observed above the canopy – Burriana orange orchard, Spain.

MissionDirect GHG and NOx emissions

Industrial agriculture—target areas just after rain on recently fertilized fields, follow evolution over several days. Key goal verify/understand timing patterns so that can interpret satellite observations at one time of day.

Forest Emissions: Reactivity, Aerosol

Visit forests at that experience high T (maximum emissions). Bring new instruments capable of establishing links between BVOC emissions, OH and aerosol composition.

Conclusions

A focussed effort aimed at understanding:

• the timing and spatial patterns of biogenic emissions

• the propagation of these emissions as a result of exchange across the PBL and convection and

• the gas and aerosol chemistry of emissions

would likely provide exciting new scientific results.