ENERGY SPECTRA OF 500-MB MERIDIONAL CIRCULATION INDICES

Abstract

Variation of the daily 500-mb hemispheric index of meridional circulation at latitudes 60N and 40N for the period 1 March 1959 to 12 July 1960 is examined by means of the spectrum-analysis method of Tukey. Some significant differences in the spectra at the two latitudes are noted. Characteristics of the spectra during different seasons are investigated by considering relatively small samples throughout the period, and evidence of seasonal variation is discussed.