VHF radar signals scattered from the equatorial mesosphere

Radio signals scattered from the equatorial mesosphere above Jicamarca, Peru have been studied. The scattered power level is dependent on look angle in the lower parts of the mesosphere. Indications are that this aspect sensitivity in the received signal cannot be adequately explained by specular reflection from stratified layers. Interferometer studies of the scattered signal have shown that there are structures in the mesosphere that have vertical velocity that varies in the horizontal direction within the antenna beam. The size of these structures is of the order of a few hundred meters. Considerations of vertical and horizontal scale sizes of these structures indicate that they are Kelvin‐Helmholtz billows drifting through the antenna beam.