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  • Author or Editor: K. Fraedrich x
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K. Fraedrich

Abstract

Lateral mixing and compensating subsidence of penetrative convection are two different techniques of parameterizing the large-scale effects of deep cumuli. Both methods are jointly derived by averaging the conservative quantities: total and potential heat separately over the area of the hot towers and the environment. If separated, lateral mixing and compensating subsidence are equivalent with respect to their energetical effect integrated over the large-scale system. Due to this fact the fractional area covered by updrafts results in a simple relation.

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K. Fraedrich
and
E. Kietzig

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.

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