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Biogenic emissions from tropical ecosystems. Michael Barkley & Paul Palmer University of Edinburgh. HCHO August 2001 (Ozone Monitoring Experiment). biogenic, pryogenic, anthropogenic. biogenic anthropogenic. biogenic anthropogenic. pryogenic anthropogenic. pyrogenic anthropogenic.
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Biogenic emissions from tropical ecosystems Michael Barkley & Paul Palmer University of Edinburgh
HCHO August 2001 (Ozone Monitoring Experiment) biogenic, pryogenic, anthropogenic biogenic anthropogenic biogenic anthropogenic pryogenic anthropogenic pyrogenic anthropogenic pryogenic Thomas Kurosu, Harvard-Smithsonian Isoprene is the main driver of variability in ΩHCHO (Palmer et al., JGR, 2003,2006)
Inverting HCHO columns for isoprene emissions GOME slant columns (July 96)
Inverting HCHO columns for isoprene emissions GOME slant columns (July 96) what GOME sees Instrument sensitivity w(s) (“scattering weight”) Apply AMF GOME vertical columns (July 96) Vertical shape factor S(s) (normalized mixing ratio) VCD = SCD / AMF
Model Transfer Function GOME slant columns (July 96) ΩHCHO=SEisop+B Apply AMF GOME vertical columns (July 96)
Model Transfer Function GOME slant columns (July 96) ΩHCHO=SEisop+B Apply AMF GOME vertical columns (July 96) Eisop~ (ΩHCHO-B) / S
Model Transfer Function GOME slant columns (July 96) ΩHCHO=SEisop+B Apply AMF GOME vertical columns (July 96) Eisop~ (ΩHCHO-B) / S GOME isoprene emission inventory
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 In situ isoprenedata @ 2.8°S, 59.4 ° W (Trostdorf et al., ACPD, 2004) Rainfall Yr = 2002 Water availability Transport of biomass burning ?
August 2001 Tropics: GEOS-CHEM 3 vs. GEOS-CHEM 4 Plots smoothed with 3x3 box-car filter!
GOME VCDs: July-Dec 1997 Plots smoothed with 3x3 box-car filter!
GEOS-CHEM v4 VCDs: July-Dec 1997 Hmm? Plots smoothed with 3x3 box-car filter!
August 2001 • Environmental factors affecting isoprene emissions: • temperature (exponential dependn) • solar irradiance • leaf area index • leaf age T2M TS GEOS 4 GEOS 3
4-3 T2M TS 4-3 GEOS 4 GEOS 3
Initial emission estimates: using GEOS-CHEM 3 8.01 TgC 9.90 TgC 15.98 TgC GOME GOME GOME MEGAN MEGAN MEGAN 9.26 TgC 11.91 TgC 9.01 TgC Plots smoothed with 3x3 box-car filter!
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 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)