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| Titel |
El Niño, global CO2 and forest growth |
| VerfasserIn |
O. Khabarova, I. Savin |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250070523
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| Zusammenfassung |
| An idea about the El Niño effect on global climate and, consequently, on forest
vegetation has appeared regularly during the last decade. Though El Niño nature is still
discussed, it is supposed that the atmospheric carbon dioxide driven by El Niño is
the most important factor, controlling growth of forests not only in near-equator
latitudes, but also worldwide [see, for example, L.R. Welp et al., Nature, Vol. 477,
2011].
To check this hypothesis we have analysed yearly mean velocity of green biomass growth
derived from 25 years long NDVI time-series for evergreen and deciduous forests,
which cover respectively 4785994 x 103 km2 and 8032392 x 103 km2 of the North
Eurasia.
It was found out that in spite of some similarity, it is impossible to explain 2-2.5 year
periodicity in forest growth by El Niño effect. Moreover, analysis of the cross-correlation
function shows that changes in trees growth usually occur 1-3 years earlier El Niño.
This means that there is no direct and expected “El Niño - increased CO2 -
intensification of vegetation” tie. The paradoxical result is that, most possibly, climate
conditions in the Northern Eurasia (determining observed forests growth in rather
high latitudes) influence global temperature and then impacts low-latitudes water
temperature that trigger El Niño. It seems that there is ~2 years floating time delay in this
process.
Therefore, “El Niño - global vegetation increase” connection is not so obvious and direct as
it was supposed before; the clarifiaction of this tie demands further extended interdisciplinary
investigations. |
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