Characteristics of mesospheric internal gravity waves observed by MU Radar

We present mesospheric wind data from MU radar at Shigaraki (34.9°N, 136.1°E), Japan, that exhibit a wave motion with a vertical wavelength of 6 km. An analysis of the horizontal and vertical components of the observed wind velocity shows that the wave motion is due to an internal inertia‐gravity wave. It behaves like a stationary wave, similar to lee waves. With the estimated wave parameters, we can derive the mean mesospheric temperature from the dispersion relation for the inertial modes. The temperature is shown to be quite consistent with the mean state of the atmosphere. It is further shown that a scattering echo layer observed simultaneously was closely connected with the vertical propagation of the gravity waves.