global bvoc emission inventories: a focus on the southeastern us colette l. heald soas workshop may...
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Global BVOC Emission Inventories:A focus on the Southeastern US
Colette L. Heald
SOAS WorkshopMay 25, 2011
Are biogenic emission models sufficient to describe BVOC and oVOC emissions in forested areas, suburban areas, urban areas?
BIOGENIC VOC EMISSIONS: MEGAN v2
i ii
F εi is the emission factor at standard conditions for vegetation type i χi, fractional areal coverage the emission activity factor is the canopy loss and production factor
E=f( )
[Guenther et al., 2006]
Baseline emission factors (for some species?) relatively well characterized in the SE…(I defer to Alex and others…)
HOW DOES UNCERTAINTY IN LAND COVER TRANSLATE TO UNCERTAINTY IN EMISSIONS?
% vegetation cover
Baseline Isoprene Emission Factor
CLM Guenther CLM-Guenther
Large uncertainties in BVOC emissions result.More important than spatial resolution??
BVOC EMISSIONS IN THE EASTERN US: MEGAN v2 in CLM
Fraction of US BVOC emitted in the SE: ~25% of isoprene, ~15% of MT, ~10% SQ, ~25% oVOC
6.8 Tg/yr
0.6 Tg/yr
0.14 Tg/yr
3.2 Tg/yr
WHAT ABOUT BI-DIRECTIONAL FLUX OF oVOCs?
Fluxes measured at the top of the canopy are NET
Risk that models are effectively double-
counting deposition?
Larger issue of evaluating simulated deposition...
And possibly implications of oVOC deposition
FUTURE ANTHROPOGENIC LAND USE CHANGE IN THE SE
Anthropogenic land use change is largely
the invasion of croplands. In the W
US this is at the expense of grasslands, but in the E US also at the expense of trees.
BVOC emissions will decrease in the SE.
WHAT ABOUT PLANTATION SPECIES IN THE SOUTHEAST?
Isoprene emissions from oil palm (basal EF: 7.8 mg/m2/h) are 4-8 times the fluxes at a
Borneo rainforest.Also saw higher estragole and
lower monoterpenes.Pictures courtesy: Nick Hewitt