Biogenic emissions from tropical ecosystemsMichael Barkley & Paul

PalmerUniversity of Edinburgh

biogenic, pryogenic, anthropogenic

pryogenicanthropogenic

biogenicanthropogenic

pryogenicpyrogenicanthropogenic

biogenicanthropogenic

Thom

as K

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anHCHO August 2006 (Ozone Monitoring Instrument)

Isoprene is the main driver of variability in ΩHCHO

(Palmer et al., JGR, 2003,2006) i

iiHCHO

HCHO Eyk

1Ω

Inverting HCHO columns for isoprene emissions GOME

slant columns (July 96)

Instrumentsensitivity w(s)(“scattering weight”)

Vertical shapefactor S(s)(normalized mixing ratio)

what GOMEsees

1

0

( ) ( )GAMF AMF w S d

Apply AMF

Inverting HCHO columns for isoprene emissions GOME

slant columns (July 96)

GOME vertical columns (July 96)

VCD = SCD / AMF

GOME slant columns (July 96)

GOME vertical columns (July 96)

Apply AMF

ΩHCHO=SEisop+B

Model Transfer Function

GOME slant columns (July 96)

GOME vertical columns (July 96)

Apply AMF

ΩHCHO=SEisop+B

Eisop~ (ΩHCHO-B) / S

Model Transfer Function

GOME slant columns (July 96)

GOME vertical columns (July 96)

GOME isopreneemission inventory

Apply AMF

ΩHCHO=SEisop+B

Eisop~ (ΩHCHO-B) / S

Model Transfer Function

The tropics: GOME observations: Jan-June 1997

Plots smoothed with 3x3 box-car filter!

The tropics: GOME observations: July-Dec 1997

Plots smoothed with 3x3 box-car filter!

Significant pyrogenic HCHO source

Plots smoothed with 3x3 box-car filter!

Grey diamonds = fires detected by ATSR

Partition Amazon into West & East regions

Plots smoothed with 3x3 box-car filter!

East region: Contribution of wild fires

Biomass burning is the main source of HCHO

Maximum in dry season

Partition Amazon into West & East regions

Plots smoothed with 3x3 box-car filter!

Isolate West Amazonian + remove fires

Plots smoothed with 3x3 box-car filter!

5 yr time series over western Amazonian

5 yr time series over western Amazonian

Transport of biomass burning ?

Water availability

In situ isoprene data @ 2.8°S, 59.4 ° W (Trostdorf et al., ACPD, 2004)

Yr = 2002 Rainfall

Plots smoothed with 3x3 box-car filter!

August 2001

Tropics: GEOS-CHEM 3 vs. GEOS-CHEM 4

GOME VCDs: July-Dec 1997

Plots smoothed with 3x3 box-car filter!

Plots smoothed with 3x3 box-car filter!

GEOS-CHEM v4 VCDs: July-Dec 1997

Hmm?

GEOS 4 GEOS 3

August 2001

Environmental factors affecting isoprene emissions: • temperature (exponential dependn)• solar irradiance• leaf area index• leaf age

T2M TS

T2M TS

4-3

4-3

GEOS 4 GEOS 3

Initial emission estimates: using GEOS-CHEM 3

Plots smoothed with 3x3 box-car filter!

9.90 TgC 8.01 TgC 15.98 TgC

9.01 TgC 9.26 TgC 11.91 TgC

GOME

MEGAN

GOME

MEGAN

GOME

MEGAN

Contribution of other VOCS ?

• Mean hourly VOC emissions 1-13 June 2006 in northern Benin ~9.3°S, 1.4°W (Data from African Monsoon Multidisciplinary campaign)

• Future work: Use Master Chemical Mechanism (MCM) to estimate time-dependent production of HCHO from limonene

Summary

• GOME & OMI HCHO columns– Have the potential to help improve our

understanding of isoprene in tropical regions & better quantify isoprene emission inventories

• GEOS-CHEM 4 very high HCHO columns over tropics– Welcome thoughts & suggestions

• Can produce initial estimates (using GEOS-CHEM 3)– Separate out pyrogenic component– Identify contributions of other VOCs (e.g.

limonene)

Further Discussion

Linear Regressions for 2001

GEOS-CHEM 3 vs. GEOS-CHEM 4

GEOS-CHEM 3

GEOS-CHEM 3 vs. GEOS-CHEM 4

GEOS-CHEM 4

GEOS-CHEM 3 vs. GEOS-CHEM 4

GEOS-CHEM 3

GEOS-CHEM 3 vs. GEOS-CHEM 4

GEOS-CHEM 4

Control Run No biomass burning

No biomass burning or biofuel No biomass burning, biofuel or biogenics

The End !