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Titel |
Atmospheric oxygen and carbon dioxide observations from two European coastal stations 2000–2005: continental influence, trend changes and APO climatology |
VerfasserIn |
C. Sirignano, R. E. M. Neubert, C. Rödenbeck, H. A. J. Meijer |
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 ; 10, no. 4 ; Nr. 10, no. 4 (2010-02-15), S.1599-1615 |
Datensatznummer |
250008105
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Publikation (Nr.) |
copernicus.org/acp-10-1599-2010.pdf |
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Zusammenfassung |
Seeking for baseline conditions has biased the atmospheric carbon dioxide
(CO2) and later on also oxygen (O2) monitoring networks towards
remote marine stations, missing part of the variability that is due to
regional anthropogenic as well as land biotic activity. We present here a
five-year record of atmospheric CO2 concentrations and oxygen/nitrogen
(O2/N2) ratio measurements from the coastal stations Lutjewad
(LUT), The Netherlands and Mace Head (MHD), Ireland, derived from flask
samples. O2/N2 ratios, a proxy for O2 concentrations,
concurrently measured with CO2 concentrations, help determine
regional CO2 fluxes by separating land fluxes from sea fluxes. Mace
Head is the closest marine baseline station to Lutjewad, located at the same
latitude, and therefore is taken as a reference. During the studied period,
from 2000 until 2005, we observed an average increase of CO2 in the
atmosphere of (1.7±0.2) ppm y−1, and a change of the
O2/N2 ratio of (−20±1) per meg y−1. The difference
between the CO2 summer minimum and the winter maximum is 14.4 ppm and
16.1 ppm at Mace Head and Lutjewad, respectively, while the paraphase
variation in the O2 signal equals 113 per meg and 153 per meg,
respectively. We also studied the atmospheric potential oxygen (APO) tracer
at both stations. By this analysis, evidence has been found that we need to
be careful when using APO close to anthropogenic CO2 sources. It could
be biased by combustion-derived CO2, and models need to take into
account daily and seasonal variations in the anthropogenic CO2
production in order to be able to simulate APO over the continents. |
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