Premium
Hemispheric coupling ‐ evidence of a cross‐equatorial planetary wave‐guide in the stratosphere
Author(s) -
Barnett J. J.
Publication year - 1975
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49710143009
Subject(s) - stratopause , solstice , stratosphere , equator , atmospheric sciences , eddy , geology , northern hemisphere , climatology , southern hemisphere , latitude , environmental science , physics , meteorology , geodesy , mesosphere , turbulence
Temperature measurements at stratopause levels made by the Selective Chopper Radiometer on the Nimbus 5 satellite have been used to study the wavenumber‐one component of the near‐stationary eddy field. Sixteen months of data are presented. Tropical amplitudes underwent a 6–month oscillation, being small (<0·2 K) near the solstices and large (∼0·6 K) near the equinoxes when the large eddies associated with winter were simultaneously present in both hemispheres. The direction of meridional phase tilt and the continuity of phase across the equator suggest that at these times a wave was able to propagate from the more active to the quieter hemisphere, reaching 30° latitude or more. These results fit with the simple theory that stationary planetary waves propagate only when the wind is westerly, since wind at these levels is westerly over the whole globe only near the equinoxes.