2002 Annual

Tuesday, 15 January 2002: 11:30 AM
Richard J. Reed and Atmospheric Tides
Richard S. Lindzen, MIT, Cambridge, MA
Between 1965 and 1969 Dick Reed published five brief papers on tides in the stratosphere. While tidal theory up to that point suggested that atmospheric tides would be primarily semidiurnal, the data from the Meteorological Rocket Network clearly showed diurnal dominance between 30 and 50 km. Dick and his colleagues showed that the temperature data from rocket were questionable, but that the data for meridional wind were reliable. They showed that tidal oscillations were vertically propagating waves with significantly varying structure in the vertical. Following the development of a theory for the diurnal tides, Reed and colleagues confirmed that low latitude tides were characterized by vertical propagation while high latitude tides were not. They also showed that minor differences between theory and observation pointed to errors in the relative importance of ozone and water vapor absorption as forcings. Reed and colleagues also showed that above 50 km semidiurnal tides became comparable to diurnal tides, and that the 180 phase shift predicted by most theories to occur near 30 km in fact occurred above 40 km. This led to the eventual recognition that there were additional sources of tidal forcing.

Supplementary URL: