Characteristics of inertia-gravity waves around jet stream from radiosonde observations in Wuhan (30.5°N, 114.4°E)

The 5 years’ radiosonde data obtained from January 2000 to December 2004 in Wuhan (30.5°N, 114.4°E) have been used for studying the behaviors of inertia-gravity waves in the vicinity of the jet stream. It is observed that the wave intensity has a similar seasonal variation with the jet stream intensity with a strong winter maximum and a summer minimum. Moreover, a similar inter-annual trend for both the wave intensity and jet stream intensity is also found. These results suggest that the jet stream may be the predominant source of the inertia-gravity waves in the troposphere and lower stratosphere over Wuhan in the period of the 5 years. It is noticed from 28 radiosonde profiles during wintertime that the energy of inertia-gravity waves exhibits upward and downward propagation respectively above and below the jet stream. This indicates that the source of the inertia-gravity waves is within the jet stream. In these cases, the twin waves below and above the jet stream usually hold similar amplitudes. The horizontal propagation of the twin waves also shows some interesting relationship.