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| Titel |
Carbon monoxide distributions from the upper troposphere to the mesosphere inferred from 4.7 μm non-local thermal equilibrium emissions measured by MIPAS on Envisat |
| VerfasserIn |
B. Funke, M. López-Puertas, M. García-Comas, G. P. Stiller, T. Clarmann, M. Höpfner, N. Glatthor, U. Grabowski, S. Kellmann, A. Linden |
| 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 ; 9, no. 7 ; Nr. 9, no. 7 (2009-04-02), S.2387-2411 |
| Datensatznummer |
250007157
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| Publikation (Nr.) |
 copernicus.org/acp-9-2387-2009.pdf |
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| Zusammenfassung |
| We present global distributions of carbon monoxide (CO) from
the upper troposphere to the mesosphere observed by the Michelson
Interferometer for Passive Atmospheric Sounding (MIPAS) on
Envisat. Vertically resolved volume mixing ratio profiles have been
retrieved from 4.7 μm limb emission spectra under
consideration of non-local thermodynamic equilibrium. The precision of
individual CO profiles is typically 5–30 ppbv
(15–40% for altitudes greater than 40 km and lower than 15 km and
30–90% within 15–40 km). Estimated systematic errors are in the order of
8–15%. Below 60 km, the vertical resolution is
4–7 km. The data set which covers 54 days from September 2003
to March 2004 has been derived with an improved retrieval version
including (i) the retrieval of log(vmr), (ii) the consideration of
illumination-dependent vibrational population gradients along the
instrument's line of sight, and (iii) joint-fitted vmr horizontal
gradients in latitudinal and longitudinal directions. A detailed
analysis of spatially resolved CO distributions during the
2003/2004 Northern Hemisphere major warming event demonstrate the
potential of MIPAS CO observations to obtain new information on
transport processes during dynamical active episodes, particularly on
those acting in the vertical. From the temporal evolution of zonally
averaged CO abundances, we derived extraordinary polar winter
descent velocities of 1200 m per day inside the recovered polar vortex
in January 2004. Middle stratospheric CO abundances show a well
established correlation with the chemical source CH4,
particularly in the tropics. In the upper troposphere, a moderate
CO decrease from September 2003 to March 2004 was
observed. Upper tropospheric CO observations provide a detailed
picture of long-range transport of polluted air masses and uplift
events. MIPAS observations taken on 9–11 September 2003 confirm the
trapping of convective outflow of polluted CO-rich air from
Southeast Asia into the Asian monsoon anticyclone, which has been
described in previous studies. Upper tropospheric CO plumes,
observed by MIPAS on this day, were predominantly located in the
Northern Hemisphere. Most of these plumes could be related to
Southeast Asian pollution by means of backward trajectory
calculations. During 20–22 October, southern hemispheric biomass
burning was the most likely source of the major CO plumes
observed over the Southern Atlantic and Indian Ocean. |
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