%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Saulquin, B.
%A Fablet, R.
%A Mercier, G.
%A Demarcq, Hervé
%A Mangin, A.
%A d' Andon, O. H. F.
%T Multiscale event-based mining in geophysical time series : characterization and distribution of significant time-scales in the sea surface temperature anomalies relatively to ENSO periods from 1985 to 2009
%D 2014
%L fdi:010062648
%G ENG
%J Ieee Journal of Selected Topics in Applied Earth Observations and Remote Sensing
%@ 1939-1404
%K Distribution of the sea surface temperature anomalies events related to the ENSO periods ; event-based mining in large geophysical datasets (big data) ; geophysical time series as series of significant time-scale events
%M ISI:000343055200033
%N 8
%P 3543-3552
%R 10.1109/jstars.2014.2329921
%U https://www.documentation.ird.fr/hor/fdi:010062648
%> https://www.documentation.ird.fr/intranet/publi/2014/11/010062648.pdf
%V 7
%W Horizon (IRD)
%X In this paper, one-dimensional (1-D) geophysical time series are regarded as series of significant time-scale events. We combine a wavelet-based analysis with a Gaussian mixture model to extract characteristic time-scales of 486 144 detected events in the Sea Surface Temperature Anomaly (SSTA) observed from satellite at global scale from 1985 to 2009. We retrieve four low-frequency characteristic time-scales of Nino Southern Oscillation (ENSO) in the 1.5- to 7-year range and show their spatial distribution. High-frequency (HF) SSTA event spatial distribution shows a dependency to the ENSO regimes, pointing out that the ENSO signal also involves specific signatures at these time-scales. These fine-scale signatures can hardly be retrieved from global EOF approaches, which tend to exhibit uppermost the low-frequency influence of ENSO onto the SSTA. In particular, we observe at global scale a major increase by 11% of the number of SSTA HF events during Nino periods, with a local maximum of 80% in Europe. The methodology is also used to highlight an ENSO-induced frequency shift during the major 1997-2000 ENSO event in the intertropical Pacific. We observe a clear shift from the high frequencies toward the 3.36-year scale with a maximum shift occurring 2 months before the ENSO maximum of energy at 3.36-year scale.
%$ 032 ; 126