Statistical Analysis and Wavenumber-Frequency Spectra of the 500 mb Geopotential along 50°S

Abstract

Daily 500 mb geopotentials gridded along 50°S are statistically analyzed for five summer and winter seasons (1959?64): 1) to establish climatic statistics of the macro-turbulent processes in the Southern Hemisphere westwind zone, and 2) to obtain a zonally averaged spectral description of the space-time (wave-number-frequency) structure of midlatitude disturbances of the Southern Hemisphere. In contrast to the Northern Hemisphere, two (instead of three) separated variance maxima are observed in the wavenumber-frequency spectra of the meridional component which contribute to transient eddy variance. They occur in the long (k=4?5,p=6?12 days, c≈ 6 m s?1) and short (k=6?7,p<6 days, c≈ 11 m s?1) period range of eastward traveling waves.