A preliminary study of the probability density distribution of the wavenumber 3 amplitude in midlatitudes of the Southern Hemisphere is undertaken with 4.25yr of 500mb height data. The wavenumber 3 amplitude probability density appears to be bimodal during winter. Analogous results during the Southern Hemisphere summer reveal a unimodal wave-number 3 amplitude probability density distribution with the single summer mode corresponding in value to the winter low amplitude mode. Synoptically, the large amplitude mode in winter corresponds to "amplified wave' of broad extent. It is suggested that the SH winter time-mean eddies for wavenumbers greater than one are the statistical residue of the intermittent large-amplitude events. Individual Southern Hemisphere large amplitude events exhibit grid point height departures from zonal symmetry comparable to their Northern Hemisphere counterparts. In addition, the summer mean eddy field is very similar to the winter low amplitude mode's mean eddy field
PLANETARY WAVE AMPLITUDE BIMODALITY IN THE SOUTHERN-HEMISPHERE / Hansen, Ar; Sutera, Alfonso. - In: JOURNAL OF THE ATMOSPHERIC SCIENCES. - ISSN 0022-4928. - 45:24(1988), pp. 3771-3783. [10.1175/1520-0469(1988)045<3771:PWABIT>2.0.CO;2]
PLANETARY WAVE AMPLITUDE BIMODALITY IN THE SOUTHERN-HEMISPHERE
SUTERA, Alfonso
1988
Abstract
A preliminary study of the probability density distribution of the wavenumber 3 amplitude in midlatitudes of the Southern Hemisphere is undertaken with 4.25yr of 500mb height data. The wavenumber 3 amplitude probability density appears to be bimodal during winter. Analogous results during the Southern Hemisphere summer reveal a unimodal wave-number 3 amplitude probability density distribution with the single summer mode corresponding in value to the winter low amplitude mode. Synoptically, the large amplitude mode in winter corresponds to "amplified wave' of broad extent. It is suggested that the SH winter time-mean eddies for wavenumbers greater than one are the statistical residue of the intermittent large-amplitude events. Individual Southern Hemisphere large amplitude events exhibit grid point height departures from zonal symmetry comparable to their Northern Hemisphere counterparts. In addition, the summer mean eddy field is very similar to the winter low amplitude mode's mean eddy fieldI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
