Preferred and unpreferred circulation types in the Northern Hemisphere wintertime phase space

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The results at the 1% significance level show that out of the 273 circulation maps investigated in the phase space there are 28 (15) that have a higher (lower) local density than that expected from a multinormal distribution. Moreover, the high number of local discrepancies is a statistically clear indication that the circulation data sample cannot come from a symmetric, fully multinormal distribution (global significance). The positive deviation from normal density properties in certain areas of the phase space (preferred maps) is offset by opposite sign deviations in other areas (unpreferred maps), ensuring multinormality only in a phase-average sense. This is clear evidence for the existence of multiple flow regimes in the hemispheric circulation. The preferred and unpreferred circulation maps were found to cluster around 6 and 5 distinct areas of the phase space, respectively. The average of the preferred or unpreferred circulation maps for each cluster was interpreted as an estimate of local density maximum or minimum areas in the phase space. Large changes in the database and the statistical methods made little change in the estimates (especially for local maxima). -from Author

Original languageEnglish
Pages (from-to)2868-2888
Number of pages21
JournalJournal of the Atmospheric Sciences
Issue number17
Publication statusPublished - Jan 1 1993

ASJC Scopus subject areas

  • Atmospheric Science

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