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| Titel |
Multi-model simulation of CO and HCHO in the Southern Hemisphere: comparison with observations and impact of biogenic emissions |
| VerfasserIn |
G. Zeng, J. E. Williams, J. A. Fisher, L. K. Emmons, N. B. Jones, O. Morgenstern, J. Robinson, D. Smale, C. Paton-Walsh, D. W. T. Griffith |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 13 ; Nr. 15, no. 13 (2015-07-02), S.7217-7245 |
| Datensatznummer |
250119868
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| Publikation (Nr.) |
 copernicus.org/acp-15-7217-2015.pdf |
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| Zusammenfassung |
| We investigate the impact of biogenic emissions on carbon monoxide (CO) and
formaldehyde (HCHO) in the Southern Hemisphere (SH), with simulations using
two different biogenic emission inventories for isoprene and monoterpenes.
Results from four atmospheric chemistry models are compared to continuous
long-term ground-based CO and HCHO column measurements at the SH Network for the
Detection of Atmospheric Composition Change (NDACC) sites, the satellite
measurement of tropospheric CO columns from the Measurement of Pollution in
the Troposphere (MOPITT), and in situ surface CO measurements from across the
SH, representing a subset of the National Oceanic and Atmospheric
Administration's Global Monitoring Division (NOAA GMD) network. Simulated
mean model CO using the Model of Emissions of Gases and Aerosols from Nature (v2.1)
computed in the frame work of the Land Community Model
(CLM-MEGANv2.1) inventory is in better agreement with
both column and surface observations than simulations adopting the emission
inventory generated from the LPJ-GUESS dynamical vegetation model
framework, which markedly underestimate measured column and surface CO at
most sites. Differences in biogenic emissions cause large differences in CO
in the source regions which propagate to the remote SH. Significant
inter-model differences exist in modelled column and surface CO, and
secondary production of CO dominates these inter-model differences, due
mainly to differences in the models' oxidation schemes for volatile organic
compounds, predominantly isoprene oxidation. While biogenic emissions are
a significant factor in modelling SH CO, inter-model differences pose an
additional challenge to constrain these emissions. Corresponding comparisons
of HCHO columns at two SH mid-latitude sites reveal that all models
significantly underestimate the observed values by approximately a factor of
2. There is a much smaller impact on HCHO of the significantly different
biogenic emissions in remote regions, compared to the source regions.
Decreased biogenic emissions cause decreased CO export to remote regions,
which leads to increased OH; this in turn results in increased HCHO
production through methane oxidation. In agreement with earlier studies, we
corroborate that significant HCHO sources are likely missing in the models in
the remote SH. |
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