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The two‐day wave in a middle atmosphere GCM
Author(s) -
Norton W. A.,
Thuburn J.
Publication year - 1996
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 - 10.1029/96gl01956
Subject(s) - atmosphere (unit) , gcm transcription factors , rossby wave , wavenumber , potential vorticity , gravity wave , wave drag , geology , physics , troposphere , atmospheric wave , atmospheric sciences , mesosphere , drag , instability , vorticity , geophysics , gravitational wave , meteorology , general circulation model , stratosphere , mechanics , drag coefficient , vortex , astronomy , optics , climate change , oceanography
A strong signal of the two‐day wave is diagnosed in a middle atmosphere GCM, with characteristics very similar to those of the observed two‐day wave. It results from an instability, but its global structure shows similarities to a Rossby‐gravity planetary normal mode. It has a remarkable potential vorticity structure in wave 3 and sometimes wave 4 and higher wavenumbers. It is shown that gravity wave drag is important in maintaining the unstable zonal mean state.