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| Titel |
Measurements of greenhouse gases and related tracers at Bialystok tall tower station in Poland |
| VerfasserIn |
M. E. Popa, M. Gloor, A. C. Manning, A. Jordan, U. Schultz, F. Haensel, T. Seifert, M. Heimann |
| 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 ; 3, no. 2 ; Nr. 3, no. 2 (2010-03-30), S.407-427 |
| Datensatznummer |
250000973
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| Publikation (Nr.) |
 copernicus.org/amt-3-407-2010.pdf |
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| Zusammenfassung |
Quasi-continuous, in-situ measurements of atmospheric CO2,
O2/N2, CH4, CO, N2O, and SF6 have been performed
since August 2005 at the tall tower station near Bialystok, in Eastern
Poland, from five heights up to 300 m. Besides the in-situ measurements,
flask samples are filled approximately weekly and measured at Max-Planck
Institute for Biogeochemistry for the same species and, in addition, for
H2, Ar/N2 and the stable isotopes 13C and 18O in
CO2. The in-situ measurement system was built based on commercially
available analysers: a LiCor 7000 for CO2, a Sable Systems "Oxzilla"
FC-2 for O2, and an Agilent 6890 gas chromatograph for CH4, CO,
N2O and SF6. The system was optimized to run continuously with
very little maintenance and to fulfill the precision requirements of the
CHIOTTO project. The O2/N2 measurements in particular required
special attention in terms of technical setup and quality assurance. The
evaluation of the performance after more than three years of operation gave
overall satisfactory results, proving that this setup is suitable for long
term remote operation with little maintenance. The precision achieved for
all species is within or close to the project requirements. The comparison
between the in-situ and flask sample results, used to verify the accuracy of
the in-situ measurements, showed no significant difference for CO2,
O2/N2, CH4 and N2O, and a very small difference for
SF6. The same comparison however revealed a statistically significant
difference for CO, of about 6.5 ppb, for which the cause could not be fully
explained.
From more than three years of data, the main features at Bialystok have been
characterized in terms of variability, trends, and seasonal and diurnal
variations. CO2 and O2/N2 show large short term variability,
and large diurnal signals during the warm seasons, which attenuate with the
increase of sampling height. The trends calculated from this dataset, over
the period August 2005 to December 2008, are 2.02±0.46 ppm/year for
CO2 and −23.2±2.5 per meg/year for O2/N2. CH4,
CO and N2O show also higher variability at the lower sampling levels,
which in the case of CO is strongly seasonal. Diurnal variations in
CH4, CO and N2O mole fractions can be observed during the warm
season, due to the periodicity of vertical mixing combined with the diurnal
cycle of anthropogenic emissions. We calculated increase rates of
10.1±4.4 ppb/year for CH4, (−8.3)±5.3 ppb/year for CO and
0.67±0.08 ppb/year for N2O. SF6 shows only few events,
and generally no vertical gradients, which suggests that there are no
significant local sources. A weak SF6 seasonal cycle has been detected,
which most probably is due to the seasonality of atmospheric circulation.
SF6 increased during the time of our measurement at an average rate of
0.29±0.01 ppt/year. |
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