Ionospheric irregularities and scintillation

One of the important research objectives of the Space Weather Program is to understand the structure and formation of ionospheric plasma-density irregularities that cause scintillation of radio waves on transionospheric links. In this paper we briefly review some aspects of scintillation and irregularities: the relationship between scintillation and ionospheric irregularities, characteristics of the equatorial and high-latitude irregularities in the context of space weather, and scintillation models. We also give examples of the application of alternative methods of data analysis, which provide a new insight into local properties of irregularities, and evidence for the nonlinear nature of ionospheric turbulence generation processes. (C) 2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved.