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Titel |
Carbon dioxide atmospheric vertical profiles retrieved from space observation using ACE-FTS solar occultation instrument |
VerfasserIn |
P. Y. Foucher, A. Chédin, R. Armante, C. Boone, C. Crevoisier, P. Bernath |
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 ; 11, no. 6 ; Nr. 11, no. 6 (2011-03-16), S.2455-2470 |
Datensatznummer |
250009501
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Publikation (Nr.) |
copernicus.org/acp-11-2455-2011.pdf |
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Zusammenfassung |
Major limitations of our present knowledge of the global distribution of
CO2 in the atmosphere are the uncertainty in atmospheric transport and the
sparseness of in situ concentration measurements. Limb viewing spaceborne
sounders such as the Atmospheric Chemistry Experiment Fourier transform
spectrometer (ACE-FTS) offer a vertical resolution of a few kilometres for
profiles, which is much better than currently flying or planned nadir
sounding instruments can achieve. After having demonstrated the feasibility
of obtaining CO2 vertical profiles in the 5–25 km altitude range with an
accuracy of about 2 ppm in a previous study, we present here the results of
five years of ACE-FTS observations in terms of monthly mean profiles of
CO2 averaged over 10° latitude bands for northern
mid-latitudes. These results are compared with in-situ aircraft measurements
and with simulations from two different air transport models. Key features of
the measured altitude distribution of CO2 are shown to be accurately
reproduced by the ACE-FTS retrievals: variation in altitude of the seasonal
cycle amplitude and extrema, seasonal change of the vertical gradient, and
mean growth rate. We show that small but significant differences from model
simulations could result from an over estimation of the model circulation
strength during the northern hemisphere spring. Coupled with column
measurements from a nadir viewing instrument, it is expected that occultation
measurements will bring useful constraints to the surface carbon flux
determination. |
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