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| Titel |
Measurements and modelling of OH and HO2 radicals over a South-East Asian tropical rainforest during the OP3 field campaign |
| VerfasserIn |
Daniel Stone, Mathew Evans, Peter Edwards, Roisin Commane, Trevor Ingham, Dwayne Heard |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250052120
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| Zusammenfassung |
| Forests are the dominant source of volatile organic compounds (VOCs) into the atmosphere,
with isoprene being the most significant species. The oxidation chemistry of these
compounds is a significant driver of local, regional and global atmospheric composition.
Recent evidence suggests a significant failing in our understanding of VOC oxidation
chemistry under low NOx conditions, with important consequences for modelling of OH and
the climate gases methane and ozone.
During the Oxidant and Particle Photochemical Processes (OP3) project over Borneo in July
2008 aircraft observations of OH and HO2 were made using FAGE (Fluorescence Assay by
Gas Expansion) . We investigate these observations with a constrained box model using the
Master Chemical Mechanism (MCM). In line with previous work we significantly
underestimate the observed OH and HO2 concentrations, with mean observed to modelled
ratios of OH and HO2 in airmasses impacted with isoprene of (5.32 ± 8.74) and (1.18 ±
0.31) respectively. A variety of mechanistic changes are made to the model, and their
impact on the model success will be described. None of the suggested mechanistic
changes allow for a good simulation of both OH and HO2 concentrations in the
model. |
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