 |
| Titel |
Analyzing the causes and spatial pattern of the European 2003 carbon flux anomaly using seven models |
| VerfasserIn |
M. Vetter, G. Churkina, M. Jung, M. Reichstein, S. Zaehle, A. Bondeau, Y. Chen, P. Ciais, F. Feser, A. Freibauer, R. Geyer, C. Jones, D. Papale, J. Tenhunen, E. Tomelleri, K. Trusilova, N. Viovy, M. Heimann |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 5, no. 2 ; Nr. 5, no. 2 (2008-04-11), S.561-583 |
| Datensatznummer |
250002386
|
| Publikation (Nr.) |
 copernicus.org/bg-5-561-2008.pdf |
|
|
|
|
|
| Zusammenfassung |
Globally, the year 2003 is associated with one of the largest atmospheric
CO2 rises on record. In the same year, Europe experienced an
anomalously strong flux of CO2 from the land to the atmosphere
associated with an exceptionally dry and hot summer in Western and Central
Europe. In this study we analyze the magnitude of this carbon flux anomaly
and key driving ecosystem processes using simulations of seven terrestrial
ecosystem models of different complexity and types (process-oriented and
diagnostic). We address the following questions: (1) how large were
deviations in the net European carbon flux in 2003 relative to a short-term
baseline (1998–2002) and to longer-term variations in annual fluxes (1980 to
2005), (2) which European regions exhibited the largest changes in carbon
fluxes during the growing season 2003, and (3) which ecosystem
processes controlled the carbon balance anomaly .
In most models the prominence of 2003 anomaly in carbon fluxes declined with
lengthening of the reference period from one year to 16 years. The 2003
anomaly for annual net carbon fluxes ranged between 0.35 and –0.63 Pg C for
a reference period of one year and between 0.17 and –0.37 Pg C for a
reference period of 16 years for the whole Europe.
In Western and Central Europe, the anomaly in simulated net ecosystem
productivity (NEP) over the growing season in 2003 was outside the
1σ variance bound of the carbon flux anomalies for 1980–2005 in all
models. The estimated anomaly in net carbon flux ranged between –42 and
–158 Tg C for Western Europe and between 24 and –129 Tg C for Central Europe
depending on the model used. All models responded to a dipole pattern of the
climate anomaly in 2003. In Western and Central Europe NEP was reduced due
to heat and drought. In contrast, lower than normal temperatures and higher
air humidity decreased NEP over Northeastern Europe. While models agree on
the sign of changes in simulated NEP and gross primary productivity in 2003
over Western and Central Europe, models diverge in the estimates of
anomalies in ecosystem respiration. Except for two process models which
simulate respiration increase, most models simulated a decrease in ecosystem
respiration in 2003. The diagnostic models showed a weaker decrease in
ecosystem respiration than the process-oriented models.
Based on the multi-model simulations we estimated the total carbon flux
anomaly over the 2003 growing season in Europe to range between –0.02 and
–0.27 Pg C relative to the net carbon flux in 1998–2002. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|