INTENSITIES AND TIME-FREQUENCY VARIABILITY OF ENSO IN THE LAST 65 YEARS
CHEN Hong-ying
XU Feng
LI Xiao-hui
XIA Tian-zhu
ZHANG yu
Abstract：Based on multiple El Ni(n)o-Southern Oscillation (ENSO) indices,Oceanic Ni(n)o index (ONI),Southern Oscillation index (SOI),Multivariate ENSO index (MEI),etc.we classified the intensities of ENSO events into five levels,analyzed the intensities and time-frequency variability of ENSO events during the period 1951-2016.Over the last 65 years,there have been 22 warm events (El Ni(n)o) and 13 cold events (La Ni(n)a).Frequency analysis is applied to the indexes of ENSO,which indicates that the percentage of strong warm events months is much more than that of strong cold events months.Three methods of time-frequency——continuous wavelet analysis,cross wavelet analysis,wavelet coherency——were used,and the results are in good agreement with the principal period (2～7-yr) and the interdecadal variability (10～16-yr) of ENSO cycle.
Keywords：ENSOtime-frequency featuresintensityinterannual&interdecadal variability
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：12( 683-694 )