Hayashi, Y., and D. G. Golder, 1988: Tropical intraseasonal oscillations appearing in a GFDL general circulation model and FGGE Data. Part II: Structure. Journal of the Atmospheric Sciences, 45(21), 3017-3033.

Abstract: Space-time spectral and filter analyses are made of the structure of the tropical intraseasonal oscillations appearing in a GFDL 30-wavenumber spectral general circulation model and the FGGE IIIb dataset.

The model's tropical zonal velocity exhibits spectral peaks with periods of 40-50 and 25-30 days at wavenumber 1 for six individual years, although the 40-50 day peak is not as pronounced as that found in the FGGE dataset. Both the eastward moving 40-50 and 25-30 day oscillations take the form of a Kelvin-Rossby wave pattern in the upper troposphere and a Rossby mode in the lower troposphere. They also take the form of a latitudinally tilted Walker cell which is modified by a meridional convergence in the boundary layer.