6.5 Day planetary waves in the mesosphere and lower thermosphere Original Research Article

The 5-day wave is a well documented feature in the lower atmosphere. Generally, the observed horizontal structure in the middle atmosphere resembles that of the Rossby (1,1) mode of classical tidal theory and the vertical structure shows little phase progression. The High Resolution Doppler Imager (HRDI) measures winds, temperatures, atomic oxygen, and ozone in the mesosphere and lower thermosphere. A wave with similar horizontal structure as the classical 5-day wave is found with periods near 6.5–7 days in HRDI measurements. The vertical structure, however, is that of a propagating wave of finite wavelength.