HR: 0800h
AN: NG41B-0434    [Abstracts]
TI: Period 7.8 Years Oscillatory Modes in the Monthly NAO Index and Temperature Records and Their Possible Phase Synchronization
AU: * Palus, M
EM: mp@cs.cas.cz
AF: Institute of Computer Science AS CR, Pod vodarenskou vezi 2, Prague 8, 18207 Czech Republic
AU: Novotna, D
EM: nov@ufa.cas.cz
AF: Institute of Atmospheric Physics AS CR, Bocni II/1401, Prague 4, 14131 Czech Republic
AB: Recently, Gamiz-Fortis et al. (J. Geophys. Res. 107(D23) 4685, 2002) have detected, using the Monte Carlo Singular System Analysis (MCSSA), an oscillatory mode with the period around 7.7 years in the winter North Atlantic Oscillation (NAO) index. Palus and Novotna (Phys. Lett. A 248 191-202, 1998) proposed an enhancement of MCSSA in which, in addition to the signal covariance structure, a complexity measure of the SSA modes is tested against surrogate data; and were able to detect a period 7.8 years oscillatory mode in long-term monthly near-surface air temperature records from several European locations. We show that using the enhanced MCSSA the period 7.8 yr oscillatory mode can be detected in the monthly NAO index, too. These modes are extracted from the raw data (expressed in the SSA/EOF basis), their instantaneous phases are computed and their relations are studied. In particular, a possibility of phase synchronization between the NAO and the temperature oscillatory modes is tested for.
DE: 3220 Nonlinear dynamics
DE: 3319 General circulation
DE: 1620 Climate dynamics (3309)
SC: Nonlinear Geophysics [NG]
MN: 2004 AGU Fall Meeting