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Titel |
A five year record of high-frequency in situ measurements of non-methane hydrocarbons at Mace Head, Ireland |
VerfasserIn |
A. Grant, E. L. Yates, P. G. Simmonds, R. G. Derwent, A. J. Manning, D. Young, D. E. Shallcross, S. O'Doherty |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1867-1381
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Measurement Techniques ; 4, no. 5 ; Nr. 4, no. 5 (2011-05-24), S.955-964 |
Datensatznummer |
250001986
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Publikation (Nr.) |
copernicus.org/amt-4-955-2011.pdf |
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Zusammenfassung |
Continuous high-frequency in situ measurements of a range of non-methane
hydrocarbons have been made at Mace Head since January 2005. Mace Head is a
background Northern Hemispheric site situated on the eastern edge of the
Atlantic. Five year measurements (2005–2009) of six C2–C5
non-methane hydrocarbons have been separated into baseline Northern
Hemispheric and European polluted air masses, among other sectors. Seasonal
cycles in baseline Northern Hemispheric air masses and European polluted air
masses arriving at Mace Head have been studied. Baseline air masses show a
broad summer minima between June and September for shorter lived species,
longer lived species show summer minima in July/August. All species
displayed a winter maxima in February. European air masses showed baseline
elevated mole fractions for all non-methane hydrocarbons. Largest elevations
(of up to 360 ppt for ethane maxima) from baseline data were observed in
winter maxima, with smaller elevations observed during the summer. Analysis
of temporal trends using the Mann-Kendall test showed small (<6 % yr−1)
but statistically significant decreases in the butanes and i-pentane between
2005 and 2009 in European air. No significant trends were found for any
species in baseline air. |
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