 |
| Titel |
Comparison of the regional CO2 mole fraction filtering approaches at a WMO/GAW regional station in China |
| VerfasserIn |
S. X. Fang, P. P. Tans, M. Steinbacher, L. X. Zhou, T. Luan |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1867-1381
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 8, no. 12 ; Nr. 8, no. 12 (2015-12-18), S.5301-5313 |
| Datensatznummer |
250116729
|
| Publikation (Nr.) |
 copernicus.org/amt-8-5301-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| The identification of atmospheric CO2 observation data which are
minimally influenced by very local emissions/removals is essential for
trend analysis, for the estimation of regional sources and sinks, and for
the modeling of long-range transport of CO2. In this study, four approaches
are used to filter the atmospheric CO2 observation records from 2009 to
2011 at one World Meteorological Organization/Global Atmosphere Watch
(WMO/GAW) regional station (Lin'an, LAN) in China. The methods are based on
the concentration of atmospheric black carbon (BC), on a statistical approach (robust
extraction of baseline signal, REBS), on CH4 as an auxiliary tracer (AUX), and on meteorological
parameters (MET). All approaches do suitably well to capture the seasonal
CO2 cycle at LAN. Differences are observed in the average regional mole
fractions with annual values in the REBS method at least 1.7 ± 0.2 ppm
higher than the other methods. The BC method may underestimate the regional
CO2 mole fractions during the winter–spring period and should be
treated with caution. The REBS method is a purely statistical method and it
may also introduce errors on the regional CO2 mole fraction
evaluations, as the filtered trend may be influenced by the "noisy" raw
data series. Although there are correlations between CH4 and CO2
mole fractions at LAN, the different source/sink regimes may introduce bias
on the regional CO2 estimation in the AUX method, typically in summer.
Overall, the MET method seems to be the most favorable because it mainly
focuses on the influence of potential local sources and sinks, and considers
diurnal variations and meteorological conditions. Using the MET method, the
annual growth rate of regional CO2 at LAN is determined to be 3.1 ± 0.01 ppm yr−1
(standard error) from 2009 to 2011. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|