论文部分内容阅读
Near 100-year observed data sets are analyzed, and the results show that the variation of seasurface temperature(SST)in the equatorial Indian Ocean has a feature as a dipole oscillation.Thesituation of the dipole oscillation mainly shows the positive phase pattern(higher SST in the westand lower SST in the east than normal)and the negative phase pattern(higher SST in the east andlower SST in the west).The amplitude of the positive phase is larger than that of the negativephase.The dipole is stronger in September—November and weaker in January—April than inother months.It principally shows obviously inter-annual(4—5 year period)and inter-decadalvariation(25—30 year period).Although the Indian Ocean dipole in the individual year seems tobe independent of ENSO in the equatorial Pacific Ocean,in general,the Indian Ocean dipole hasobviously negative correlation with the Pacific Ocean “dipole”(similar to the inverse phase ofENSO).The atmospheric zonal(Walker) circulation is fundamental for relating the two dipoles toeach other.
Near 100-year observed data sets are analyzed, and the results show that the variation of seasurface temperature (SST) in the equatorial Indian Ocean has a feature as a dipole oscillation. The effect of the dipole oscillation mainly shows the positive phase pattern (higher SST in the westand lower SST in the east than normal) and the negative phase pattern (higher SST in the east andlower SST in the west). The amplitude of the positive phase is larger than that of the negativephase. The dipole is stronger in September- November and April in the month of January-April than in other months. It principally shows obviously inter-annual (4-5 year period) and inter-decadal variation (25-30 year period) .Although the Indian Ocean dipole in the individual year seems to be independent of of ENSO in the equatorial Pacific Ocean, in general, the Indian Ocean dipole has an apparent negative correlation with the Pacific Ocean “dipole” (similar to the inverse phase of ENSO). The atmospheric zonal (Walker) circulation is fundament mental for relating the two dipoles toeach other.