 |
| Titel |
Information transfer across the scales of climate variability: The effect of the 7–8 year cycle on the annual and interannual scales |
| VerfasserIn |
Milan Palus, Nikola Jajcay, Jaroslav Hlinka, Sergey Kravtsov, Anastasios Tsonis  |
| Konferenz |
EGU General Assembly 2016
|
| Medientyp |
Artikel
|
| Sprache |
en
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250130349
|
| Publikation (Nr.) |
 EGU/EGU2016-10594.pdf |
|
|
|
|
|
| Zusammenfassung |
| Complexity of the climate system stems not only from the fact that it is variable over a huge
range of spatial and temporal scales, but also from the nonlinear character of the
climate system that leads to interactions of dynamics across scales. The dynamical
processes on large time scales influence variability on shorter time scales. This
nonlinear phenomenon of cross-scale causal interactions can be observed due to the
recently introduced methodology [1] which starts with a wavelet decomposition of a
multi-scale signal into quasi-oscillatory modes of a limited bandwidth, described using
their instantaneous phases and amplitudes. Then their statistical associations are
tested in order to search for interactions across time scales. An information-theoretic
formulation of the generalized, nonlinear Granger causality [2] uncovers causal
influence and information transfer from large-scale modes of climate variability with
characteristic time scales from years to almost a decade to regional temperature
variability on short time scales. In analyses of air temperature records from various
European locations, a quasioscillatory phenomenon with the period around 7–8 years
has been identified as the factor influencing variability of surface air temperature
(SAT) on shorter time scales. Its influence on the amplitude of the SAT annual cycle
was estimated in the range 0.7–1.4 ∘C and the effect on the overall variability of
the SAT anomalies (SATA) leads to the changes 1.5–1.7 ∘C in the annual SATA
means. The strongest effect of the 7–8 year cycle was observed in the winter SATA
means where it reaches 4–5 ∘C in central European station and reanalysis data
[3].
This study is supported by the Ministry of Education, Youth and Sports of the Czech
Republic within the Program KONTAKT II, Project No. LH14001.
[1] M. Palus, Phys. Rev. Lett. 112 078702 (2014)
[2] M. Palus, M. Vejmelka, Phys. Rev. E 75, 056211 (2007)
[3] N. Jajcay, J. Hlinka, S. Kravtsov, A. A. Tsonis, M. Palus, Time-scales of the European
surface air temperature variability: The role of the 7–8 year cycle. Geophys. Res. Lett., in
press, DOI: 10.1002/2015GL067325 |
|
|
|
|
|
|