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A zonal wave 3 index for the Southern Hemisphere
Author(s) -
Raphael M. N.
Publication year - 2004
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2004gl020365
Subject(s) - geopotential height , zonal flow (plasma) , climatology , northern hemisphere , variation (astronomy) , magnitude (astronomy) , atmosphere (unit) , sign (mathematics) , atmospheric sciences , amplitude , zonal and meridional , geology , geopotential , meridional flow , environmental science , meteorology , precipitation , physics , mathematics , mathematical analysis , plasma , quantum mechanics , astronomy , astrophysics , tokamak
In this study 500 hPa geopotential heights from the NCAR‐NCEP Reanalysis are used to calculate an index describing the spatial and temporal characteristics of zonal wave three (ZW3) in the high latitude Southern Hemisphere atmosphere. The index spans the period 1958–2001. Wavelet analysis of the index shows the strong interannual variation which is characteristic of ZW3 and also reveals significant, high amplitude decadal‐scale variation. This interannual variation takes the form of marked fluctuation in sign and magnitude of the index. It appears to occur when there are rapid changes from strongly meridional to strongly zonal flow or vice versa. Initial indications are that some of this variability may be associated with ENSO events.