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| Titel |
Time series of 12CO and 13CO at northern mid-latitudes: determination of partial column and δ¹³C seasonal and interannual variations |
| VerfasserIn |
E. Mahieu, P. Duchatelet, C. P. Rinsland, Q. Li, C. D. Boone, K. A. Walker, P. F. Bernath, M. De Mazière, B. Dils |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250028017
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| Zusammenfassung |
| Carbon monoxide (CO) is an important reactive gas in the troposphere. It is emitted at the
ground level by fossil fuel combustion and biomass burning. Biogenic sources and oceans as
well as oxidation of methane and nonmethane hydrocarbons complete the emissions
budget. Large uncertainties still affect the relative contributions of the identified
anthropogenic and natural sources. Destruction by the hydroxyl radical (OH) is the
main removal process for CO in both the troposphere and the stratosphere. The
resulting average tropospheric lifetime of CO varies from several weeks to a few
months.
Two approaches have been developed and optimized to independently retrieve
abundances of 12CO and 13CO from high-resolution ground-based infrared solar
spectra, using sets of carefully selected lines and the SFIT-2 (v3.91) algorithm
which implements the optimal estimation method. The corresponding products will
be described and characterized in terms of error budget and information content.
These strategies have allowed us to produce partial column time series of 12CO
and 13CO, using spectra recorded on a regular basis at the Jungfraujoch station
(46.5ºN, 8.0ºE, 3580 m asl, Swiss Alps), a site of the Network for the Detection of
Atmospheric Composition Change (NDACC). The seasonal and interannual changes
observed in the12CO,13CO and δ13C (13C/12C) data sets will be presented and
discussed.
Complementary zonal mean time series derived from occultation measurements collected
by the ACE-FTS instrument onboard the Canadian SCISAT-1 platform since 2004 will also
be included and analyzed, focusing on the upper troposphere-lower stratosphere region of the
atmosphere.
Finally, we will use GEOS-Chem 3-D chemistry transport model results to help in the
interpretation of the short- and long-term variations characterizing the ground-based and
satellite data sets, focusing on the factors influencing the partitioning between the two CO
isotopologues. |
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