Proceedings of the Korea Water Resources Association Conference (한국수자원학회:학술대회논문집)
- 2003.05a
- /
- Pages.151-158
- /
- 2003
ON THE LONG-TERM VARIABILITY OF SOUTHERN OSCILLATION INDEX
- Jin, Young-Hoon (Graduate student, Institute of Environmental Systems, Kyushu University) ;
- Kawamura, Akira (Institute of Environmental Systems, Kyushu University) ;
- Jinno, Kenji (Institute of Environmental Systems, Kyushu University) ;
- Iseri, Yoshihiko (Graduate student, Institute of Environmental Systems, Kyushu University)
- Published : 2003.05.01
Abstract
Recently, there has been considerable interest in the influence of El Nino/Southern Oscillation (ENSO) on a global scale. ENSO has been measured by a simple index called Southern Oscillation Index (SOI). The statistical characteristics of SOI have been also focused to reveal the influence of ENSO. The SOI trend shows that El Nino events are generally getting stronger and more frequently occurring than La Nina events. However, the variation of SOI has varied significantly in a long-term. The SOI values are computed using the mean value and its standard deviation of the base period from 1951 to 1980. In the present study, the different base periods are applied to compute the SOI values and the influence of the different base periods is investigated in detail to reveal the long-term variation of SOI From the results, we could conclude that the present SOI should be carefully considered as a criterion to judge whether the El Nino and La Nina events are occurring.
Keywords