Observation of inertial waves in the stratosphere

A series of radiosonde flights over Laverton, Victoria (38°S), is found to have sufficient vertical (100m) and temporal (3 h) resolution, and sufficient length (28 days) to detect inertial waves. Fourier analysis shows that in the stratosphere there is a strong anticyclonic rotation of the wind vector which has energy concentrated near the local inertial frequency. This rotation is associated with a vertical wavelength between 1 and 3 km, and a downward phase propagation. There is no sign of inertial waves in the troposphere. The waves appear to be generated below the stratosphere and spread upwards.