大気大循環の年々変動と異常天候 (II)

Abstract

Composite analyses are made for zonal mean wind and ultra-long waves with zonal wave-numbers 1, 2 and 3, by using 500 mb JMA season mean height data. Year-to-year variationsof height field are examined, with referring to the composite height field: The extreme 1982/83case of El Nino event shows the similar pattern of height anomaly field to the composite field forSOI<-1.To investigate dominant periods and their relationship of the variability of general circu-lation and SOI, spectral and cospectral analyses of SOI, Zonal index (ZI) and index of Polarvortex intensity (PVI) are performed as the first step.