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| Titel |
Satellite-inferred European carbon sink larger than expected |
| VerfasserIn |
M. Reuter, M. Buchwitz, M. Hilker, J. Heymann, O. Schneising, D. Pillai, H. Bovensmann, J. P. Burrows, H. Bösch, R. Parker, A. Butz, O. Hasekamp, C. W. O'Dell, Y. Yoshida, C. Gerbig, T. Nehrkorn, N. M. Deutscher, T. Warneke, J. Notholt, F. Hase, R. Kivi, R. Sussmann, T. Machida, H. Matsueda, Y. Sawa |
| 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. 24 ; Nr. 14, no. 24 (2014-12-22), S.13739-13753 |
| Datensatznummer |
250119263
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| Publikation (Nr.) |
 copernicus.org/acp-14-13739-2014.pdf |
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| Zusammenfassung |
| Current knowledge about the European terrestrial biospheric carbon sink, from
the Atlantic to the Urals, relies upon bottom-up inventory and surface flux
inverse model estimates (e.g. 0.27±0.16 GtC a−1 for 2000–2005
(Schulze et al., 2009), 0.17±0.44 GtC a−1 for 2001–2007
(Peters et al.,
2010), 0.45±0.40 GtC a−1 for 2010
(Chevallier et al., 2014), 0.40±0.42 GtC a−1 for 2001–2004
(Peylin et al., 2013)). Inverse models assimilate in situ CO2 atmospheric
concentrations measured by surface-based air sampling networks. The intrinsic
sparseness of these networks is one reason for the relatively large flux
uncertainties (Peters et al., 2010; Bruhwiler
et al., 2011). Satellite-based CO2
measurements have the potential to reduce these uncertainties
(Miller et al., 2007;
Chevallier et al., 2007). Global inversion experiments using
independent models and independent GOSAT satellite data products consistently
derived a considerably larger European sink (1.0–1.3 GtC a−1 for
09/2009–08/2010 (Basu et al.,
2013), 1.2–1.8 GtC a−1 in 2010
(Chevallier et al., 2014)). However, these results have been considered
unrealistic due to potential retrieval biases and/or transport errors
(Chevallier et al., 2014) or have not been discussed at all
(Basu et al.,
2013; Takagi et al., 2014). Our analysis comprises a regional inversion
approach using STILT (Gerbig et al., 2003; Lin
et al., 2003) short-range (days)
particle dispersion modelling, rendering it insensitive to large-scale
retrieval biases and less sensitive to long-range transport errors. We show
that the satellite-derived European terrestrial carbon sink is indeed much
larger (1.02±0.30 GtC a−1 in 2010) than previously expected. This
is qualitatively consistent among an ensemble of five different inversion
set-ups and five independent satellite retrievals (BESD (Reuter et al., 2011)
2003–2010, ACOS (O’Dell et al., 2012) 2010, UoL-FP (Cogan et al.,
2012) 2010,
RemoTeC (Butz et al., 2011) 2010, and NIES (Yoshida et al., 2013) 2010) using
data from two different instruments (SCIAMACHY (Bovensmann et al., 1999) and
GOSAT (Kuze et al., 2009)). The difference to in situ based inversions
(Peylin et al., 2013), whilst large with respect to the mean reported European
carbon sink (0.4 GtC a−1 for 2001–2004), is similar in magnitude
to the reported uncertainty (0.42 GtC a−1). The highest gain in
information is obtained during the growing season when satellite observation
conditions are advantageous, a priori uncertainties are largest, and the
surface sink maximises; during the dormant season, the results are dominated
by the a priori. Our results provide evidence that the current understanding
of the European carbon sink has to be revisited. |
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