Evidence for equatorial Kelvin modes in Nimbus-7 LIMS

Equatorial Kelvin waves have emerged as an important source of westerly momentum for the tropical stratosphere. The present investigation is concerned with an analysis of remotely derived temperatures from Nimbus-7 LIMS (Limb Infrared Monitor of the Stratosphere). It is found that eastward propagating disturbances are present in two independent LIMS data sets. The disturbances manifest themselves consistently at several levels throughout the stratosphere and account for much of the tropical temperature variance out to latitudes where extratropical signals become large. Compelling evidence is found for several distinct phase velocities. Spectral analysis indicates isolated eastward variance at principally two frequencies for both wavenumbers.