Observations of stable layers in the troposphere and stratosphere using VHF radar

Observations of the Sunset radar located near Boulder, Colorado, reveal order of magnitude enhancements of the signals received on the vertically directed antenna over the signals received nearly simultaneously on the antennas directed off the vertical. These enhancements are caused by Fresnel reflection and Fresnel scattering from thin stable layers. They are most pronounced from stable regions of the atmosphere in the troposphere and stratosphere and especially from the lower stratosphere just above the tropopause. The ability to detect stable layers from enhanced echoes on VHF radars is applied to the determination of the tropopause. It is concluded that the height of the tropopause can be determined within a few hundred meters.