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| Titel |
Reconstruction of Northern Hemisphere 1950-2010 atmospheric non-methane hydrocarbons |
| VerfasserIn |
D. Helmig, V. Petrenko, P. Martinerie, E. Witrant, T. Röckmann, A. Zuiderweg, R. Holzinger, J. Hueber, C. Thompson, J. W. C. White, W. Sturges, A. Baker, T. Blunier, D. Etheridge, M. Rubino, P. Tans |
| 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 ; 14, no. 3 ; Nr. 14, no. 3 (2014-02-10), S.1463-1483 |
| Datensatznummer |
250118363
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| Publikation (Nr.) |
 copernicus.org/acp-14-1463-2014.pdf |
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| Zusammenfassung |
| The short-chain non-methane hydrocarbons (NMHC) are mostly emitted into the
atmosphere by anthropogenic processes. Recent studies have pointed out a
tight linkage between the atmospheric mole fractions of the NMHC ethane and
the atmospheric growth rate of methane. Consequently, atmospheric NMHC are
valuable indicators for tracking changes in anthropogenic emissions,
photochemical ozone production, and greenhouse gases. This study investigates
the 1950–2010 Northern Hemisphere atmospheric C2–C5 NMHC ethane,
propane, i-butane, n-butane, i-pentane, and n-pentane by (a)
reconstructing atmospheric mole fractions of these trace gases using firn air
extracted from three boreholes in 2008 and 2009 at the North Greenland Eemian
Ice Drilling (NEEM) site and applying state-of-the-art models of trace gas
transport in firn, and by (b) considering eight years of ambient NMHC
monitoring data from five Arctic sites within the NOAA Global Monitoring
Division (GMD) Cooperative Air Sampling Network. Results indicate that these
NMHC increased by ~40–120% after 1950, peaked around 1980 (with
the exception of ethane, which peaked approximately 10 yr earlier), and have
since dramatically decreased to be now back close to 1950 levels. The earlier
peak time of ethane vs. the C3–C5 NMHC suggests that different
processes and emissions mitigation measures contributed to the decline in
these NMHC. The 60 yr record also illustrates notable increases in the
ratios of the isomeric iso-/n-butane and iso-/n-pentane
ratios. Comparison of the reconstructed NMHC histories with 1950–2000
volatile organic compounds (VOC) emissions data and with other recently
published ethane trend analyses from ambient air Pacific transect data showed
(a) better agreement with North America and Western Europe emissions than
with total Northern Hemisphere emissions data, and (b) better agreement with
other Greenland firn air data NMHC history reconstructions than with the
Pacific region trends. These analyses emphasize that for NMHC, having
atmospheric lifetimes on the order of < 2 months, the Greenland firn
air records are primarily a representation of Western Europe and North
America emission histories. |
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