TY - JOUR
T1 - Impact of quasi-decadal variability in the tropical Pacific on ENSO modulations
AU - Hasegawa, Takuya
AU - Hanawa, Kimio
N1 - Funding Information:
The authors wish to express their sincere thanks to members of the Physical Oceanography Group at Tohoku University and the Oceanographic Research Department at the Meteorological Research Institute/Japan Meteorological Agency for their useful discussion. The first author (TH) was financially supported by the 21st Century Center-Of-Excellence (COE) Program, “Advanced Science and Technology Center for the Dynamic Earth (E-ASTEC)”, at Tohoku University, and by Research Fellowships of the Japan Society for the Promotion of Science for Young Scientists. The authors also wish to thank two reviewers for their comments and suggestions that helped to improve our original manuscript.
PY - 2006/4
Y1 - 2006/4
N2 - The impact of quasi-decadal (QD: 8 to 18 years) variability in the tropical Pacific on ENSO events is investigated. It is found that there is a significant difference in the behavior of ENSO events between the phases of positive and negative anomalies of the QD Niño-3.4 index. During the period of negative QD-scale Niño-3.4 index, ENSO events, especially La Niña events, occur more frequently, and larger amplitudes of thermal anomalies related to El Niño events appear over the central to eastern equatorial Pacific. Furthermore, propagations of upper ocean heat content anomaly and a phase relationship between upper ocean heat content and Niño-3 index in the equatorial Pacific, which have been pointed out by previous studies, are clearly detected during the period of negative QD Niño-3.4 index.
AB - The impact of quasi-decadal (QD: 8 to 18 years) variability in the tropical Pacific on ENSO events is investigated. It is found that there is a significant difference in the behavior of ENSO events between the phases of positive and negative anomalies of the QD Niño-3.4 index. During the period of negative QD-scale Niño-3.4 index, ENSO events, especially La Niña events, occur more frequently, and larger amplitudes of thermal anomalies related to El Niño events appear over the central to eastern equatorial Pacific. Furthermore, propagations of upper ocean heat content anomaly and a phase relationship between upper ocean heat content and Niño-3 index in the equatorial Pacific, which have been pointed out by previous studies, are clearly detected during the period of negative QD Niño-3.4 index.
KW - ENSO modulation
KW - Quasi-decadal variation
KW - Upper ocean heat content
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U2 - 10.1007/s10872-006-0047-5
DO - 10.1007/s10872-006-0047-5
M3 - Article
AN - SCOPUS:33645087372
SN - 0916-8370
VL - 62
SP - 227
EP - 234
JO - Journal of Oceanography
JF - Journal of Oceanography
IS - 2
ER -