大気大循環の年々変動と異常天候(III)

Abstract

By using 500 hPa JMA monthly mean height data for the period 1946-85 and NMCmonthly mean height and temperature data for the period 1964-82, we made one-dimensionalFourier analyses along latitudinal circles, and spectral analyses based on the Maximum Entro-py Method (MEM). Taking account of the results of the spectral analyses, we applied fourbandpass time filters to the Southern Oscillation Index (SOI), zonal mean height and Fouriercoeffcients of height with zonal wavenuinbers 1 to 3, zonal mean wind, and zonal mean tem-perature. The band-pass filtered time-series of zonal mean quantities show clear periodicfluctuations, especially for the 2-3 and 3-5 year bands in the high latitudes. Their charac-teristic features in the latitude-time section are closely related to the variation of SOI.