Evidence for high Schmidt numbers at 224 MHz has been seen in incoherent backscatter from the mesopause region. Schmidt numbers in excess of around 2 indicate that the electron gas inner scale is no longer representative of the neutral atmosphere turbulence, an effect that could occur in the presence of heavy ions such as those associated with noctilucent clouds. In addition to examples of Schmidt number profiles, we present some tentative ion mass estimates, and explain how these may be used to deduce the hydration path of cluster ions. ¿ American Geophysical Union 1988