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| Titel |
Changes in CO2 trends observed in the lower troposphere over West
Siberia |
| VerfasserIn |
Boris D. Belan, Toshinobu Machida, Motoki Sasakawa, Shamil Maksyutov, Denis Davydov, Alexandr Fofonov, Mikhail Arshinov |
| 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 |
250131231
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| Publikation (Nr.) |
 EGU/EGU2016-11616.pdf |
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| Zusammenfassung |
| Long-term airborne observations of greenhouse gases carried out in the troposphere over
south-western area of West Siberia since 1997 allowed some specific features in CO2
trends to be revealed at different heights. At an altitude of 7 km above ground level
(AGL), the average annual rate of CO2 increase was 1.72 ppm yr−1. The main
distinctive features in the tendencies of CO2 mixing ratio have been found in the
lower troposphere. Thus, for the period from 1997 to 2004, July concentrations
of CO2 at an altitude of 500 m AGL increased slightly with a rate of 0.17 ppm
yr−1, while since 2005 they began to rise dramatically with a rate of 3.64 ppm
yr−1.
Analysis of the possible causes of such long-term behavior showed that it was resulted
from neither reduction of forest area, nor wildfires, nor forest diseases. Also it is impossible
to state that reducing CO2 sink has been caused by the impact of climate changes on
ecosystems.
Possibly, anthropogenic CO2 accumulation resulted in that Siberian forests cannot
assimilate such additional amount of carbon dioxide. A decrease in the sink for atmospheric
CO2 is also observed in the Amazon (Brienen et al. 2015). Brienen et al. (2015) assume that
it may be caused by a sustained long-term increase in tree mortality. There is also a
supposition that it can be a result of a vegetation replacement by other types of plants or
young trees, which absorb less amount of CO2 (Kunstler et al., 2015; Crowther T.
W., 2015). However, it seems highly unlikely to test these hyposeses in the near
future due to a huge area of West Siberia, most regions of which are difficult to
access.
This work was funded by the Global Environment Research Account for National
Institutes of the Ministry of the Environment (Japan) and Russian Foundation for Basic
Research (grant No. 14-05-00590).
Brienen R.J.W. et al. 2015. Long-term decline of the Amazon carbon sink. Nature. 519
(7543), 344–348.
Kunstler G. et al. 2015. Plant functional traits have globally consistent effects on
competition. Nature. 528 (7583), 34–38.
Crowther T.W. et al. 2015. Mapping tree density at a global scale. Nature. 525 (7568),
201–205. |
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