On the 60-month cycle of multivariate ENSO index
- 163 Downloads
Many point indices have been developed to describe El Niño/Southern Oscillation, but the multivariate El Niño Southern Oscillation (ENSO) index (MEI) is considered the most representative since it links six different meteorological parameters measured over the tropical Pacific. Spectral analysis with appropriate data reduction techniques of monthly values of MEI (1950–2008) has allowed the identification of a large 60-month cycle, statistically confident at a level larger than 99%. The highest values of MEI (typical of El Niño events) and the lowest values of MEI (typical of La Niña events) are concordant with respective maxima and minima values of the identified 60-month cycle.
KeywordsPoint Index Multivariate ENSO Index Darwin Atmospheric Pressure High Statistical Stability Multivariate ENSO Index Index
- Bendat JS, Piersol AG (1971) Random data analysis: measurement procedures. Wiley-Interscience, New York p 407Google Scholar
- Wolter K, Timlin MS (1993) Monitoring ENSO in COADS with a seasonally adjusted principal component index. Proceedings of the 17th Climate Diagnostics Workshop, Norman, OK, NOAA/N MC/CAC, NSSL, Oklahoma Climate Survey, CIMMS and the School of Meteorology, University of Oklahoma, pp 52–57Google Scholar
- Wolter K, Timlin MS (1998) Measuring the strength of ENSO events—how does 1997/98 rank? Weather 53:315–324Google Scholar