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| Titel |
CO emission and export from Asia: an analysis combining complementary satellite measurements (MOPITT, SCIAMACHY and ACE-FTS) with global modeling |
| VerfasserIn |
S. Turquety, C. Clerbaux, K. Law, P.-F. Coheur, A. Cozic, S. Szopa, D. A. Hauglustaine, J. Hadji-Lazaro, A. M. S. Gloudemans, H. Schrijver, C. D. Boone, P. F. Bernath, D. P. Edwards |
| 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 ; 8, no. 17 ; Nr. 8, no. 17 (2008-09-03), S.5187-5204 |
| Datensatznummer |
250006359
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| Publikation (Nr.) |
 copernicus.org/acp-8-5187-2008.pdf |
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| Zusammenfassung |
| This study presents the complementary picture of the pollution outflow
provided by several satellite observations of carbon monoxide (CO), based on
different observation techniques. This is illustrated by an analysis of the
Asian outflow during the spring of 2005, through comparisons with
simulations by the LMDz-INCA global chemistry transport model. The CO
observations from the MOPITT and SCIAMACHY nadir sounders, which provide
vertically integrated information with excellent horizontal sampling, and
from the ACE-FTS solar occultation instrument, which has limited spatial
coverage but allows the retrieval of vertical profiles, are used. Combining
observations from MOPITT (mainly sensitive to the free troposphere) and
SCIAMACHY (sensitive to the full column) allows a qualitative evaluation of
the boundary layer CO. The model tends to underestimate this residual
compared to the observations, suggesting underestimated emissions,
especially in eastern Asia. However, a better understanding of the
consistency and possible biases between the MOPITT and SCIAMACHY CO is necessary
for a quantitative evaluation. Underestimated emissions, and possibly too
low lofting and underestimated chemical production in the model, lead to an
underestimate of the export to the free troposphere, as highlighted by
comparisons with MOPITT and ACE-FTS. Both instruments observe large
trans-Pacific transport extending from ~20° N to ~60° N,
with high upper tropospheric CO observed by ACE-FTS above the eastern
Pacific (with values of up to 300 ppbv around 50° N at 500 hPa and up to
~200 ppbv around 30° N at 300 hPa). The low vertical and horizontal
resolutions of the global model do not allow the simulation of the strong
enhancements in the observed plumes. However, the transport patterns are
well captured, and are mainly attributed to export from eastern Asia, with
increasing contributions from South Asia and Indonesia towards the tropics.
Additional measurements of C2H2, C2H6 and HCN by ACE-FTS
provide further information on the plume history. C2H2 and
C2H6 enhancements are well correlated with the CO plumes,
indicating common sources and rapid trans-Pacific transport. HCN
observations show that the biomass burning contributes mainly at latitudes
lower than ~40° N. This study provides a first step towards a full
combination of complementary observations, but also highlights the need for
a better evaluation of consistency between the datasets in order to allow
precise quantitative analyses. |
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