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Izumo, Takeshi; Masson, Sebastien; Vialard, Jerome; De Boyer Montegut, Clement; Behera, Swadhin K.; Madec, Gurvan; Takahashi, Keiko; Yamagata, Toshio. |
The Madden-Julian oscillation (MJO) is the main component of intraseasonal variability of the tropical convection, with clear climatic impacts at an almost-global scale. Based on satellite observations, it is shown that there are two types of austral-summer MJO events (broadly defined as 30-120 days convective variability with eastward propagation of about 5 m/s). Equatorial MJO events have a period of 30-50 days and tend to be symmetric about the equator, whereas MJO events centered near 8A degrees S tend to have a longer period of 55-100 days. The lower-frequency variability is associated with a strong upper-ocean response, having a clear signature in both sea surface temperature and its diurnal cycle. These two MJO types have different interannual... |
Tipo: Text |
Palavras-chave: Intraseasonal Madden-Julian oscillation (MJO); Seychelles-Chagos thermocline ridge/thermocline dome of the Indian Ocean; Indian Ocean dipole (IOD); El Nino southern oscillation (ENSO); Diurnal cycle; Oceanic diurnal warm layers; Air-sea interactions; Ocean-atmosphere coupling; Interannual variations; Mixed layer; Australian weather. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00013/12416/9221.pdf |
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Izumo, Takeshi; Vialard, Jerome; Lengaigne, Matthieu; De Boyer Montegut, Clement; Behera, Swadhin K.; Luo, Jing-jia; Cravatte, Sophie; Masson, Sebastien; Yamagata, Toshio. |
El Nino-Southern Oscillation (ENSO) consists of irregular episodes of warm El Nino and cold La Nina conditions in the tropical Pacific Ocean(1), with significant global socio-economic and environmental impacts(1). Nevertheless, forecasting ENSO at lead times longer than a few months remains a challenge(2,3). Like the Pacific Ocean, the Indian Ocean also shows interannual climate fluctuations, which are known as the Indian Ocean Dipole(4,5). Positive phases of the Indian Ocean Dipole tend to co-occur with El Nino, and negative phases with La Nina(6-9). Here we show using a simple forecast model that in addition to this link, a negative phase of the Indian Ocean Dipole anomaly is an efficient predictor of El Nino 14 months before its peak, and similarly, a... |
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Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00002/11304/7831.pdf |
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