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| Titel |
Combining an automated closed chamber system with a quantum cascade laser for high-frequency measurements of δ13C of ecosystem CO2 fluxes |
| VerfasserIn |
Andreas Brændholt, Andreas Ibrom, Per Ambus, Klaus Steenberg Larsen, Kim Pilegaard |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250153272
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| Publikation (Nr.) |
 EGU/EGU2017-18225.pdf |
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| Zusammenfassung |
| Advances in laser spectroscopy have allowed for online high-frequency measurements of the
isotopic composition of C and O in CO2, thereby providing new ways to investigate
CO2 flux partitioning and carbon cycling in natural ecosystems. In this study, we
combined an Aerodyne quantum cascade laser for CO2 isotopes with the LI-COR
LI-8100A/8150 automatic closed chamber system to yield the δ13C of CO2 during automated
closed chamber measurements. The system was used during a two month campaign
in a Danish beech forest, where δ13C was measured for a total of 12 chambers,
each enclosing either intact soil, trenched soil, tree stem or a tree root. By applying
the Keeling plot methodology to the change in δ13C of CO2 during a chamber
measurement, the isotopic composition of the respired CO2 was determined. The poster
presents δ13C data of ecosystem CO2 fluxes on both a daily and diel scale for soil,
roots and tree stems that revealed interesting information about forest ecosystem
carbon cycling. Furthermore, it explores the unique setup and the tests required for
precise automated chamber-based measurements of δ13C by a quantum cascade
laser.
Acknowledgements: This study was funded by the free Danish Ministry for Research,
Innovation and higher Education, the free Danish Research Council (DFF – 1323-00182). |
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