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| Titel |
CO2 and greening observations indicate increasing light use efficiency in northern terrestrial ecosystems |
| VerfasserIn |
Rebecca Thomas, Iain Colin Prentice, Heather Graven, Joshua Fisher, Maoyi Huang, Deborah Huntzinger, Akihiko Ito, Andy Jacobson, Atul Jain, Jiafu Mao, Anna Michalak, Shushi Peng, Ben Poulter, Daniel Ricciuto, Xiaoying Shi, Christopher Schwalm, Hanqin Tian, Ning Zeng |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250133695
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| Publikation (Nr.) |
 EGU/EGU2016-14335.pdf |
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| Zusammenfassung |
| Observations show an increasing amplitude in the seasonal cycle of CO2 (SCA) north of 45∘
N of 56±9.8% over the last 50 years and an increase in vegetation greenness of 7.5-15% in
high northern latitudes since the 1980’s. However the causes of these changes remain
uncertain. Historical simulations from terrestrial biosphere models in the Multi-scale
Synthesis and Terrestrial Model Inter-comparison Project (MsTMIP) are compared to these
observations, using the TM3 atmospheric transport model to translate surface fluxes into CO2
concentrations. We find that models underestimate the absolute change in SCA by 47-105%
but capture the mean greening trend. Modelled increases in greenness are driven by
warming, whereas SCA changes are driven by increasing CO2. We suggest that
a key factor contributing to observed SCA increase is increased vegetation light
use efficiency (LUE), and that LUE is likely to have increased more strongly than
simulated in current models over 1960-2010. We highlight several mechanisms, not
adequately simulated by current models, that could be responsible for this LUE increase. |
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