Altitude variations of middle-latitude topside ionospheric electron-density profiles

• Published in: Advances in space research Vol. 37; no. 5; pp. 951 - 957
• Main Authors: Webb, P.A., Benson, R.F., Grebowsky, J.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2006
• Subjects: Electron density profiles; Ion composition; O +/H + transition height; Topside ionosphere; Topside sounding; O +/H + transition height; Electron density profiles; Topside ionosphere; Topside sounding; Ion composition
• ISSN: 0273-1177; 1879-1948
• DOI: 10.1016/j.asr.2005.05.130

An approach to determine the dependence of the mid-latitude topside ionospheric electron number density ( N e) altitude distributions and ion composition changes on long-term solar-cycle variations and short-term solar-wind and magnetic disturbances has been developed. This approach focuses on N e altitude profiles from the height of the ionospheric N e maximum to ∼3000 km as deduced from ISIS (International Satellites for Ionospheric Studies) topside-sounder data. These data, obtained over a two-decade time interval, can be used to investigate secular changes in the topside N e profiles, which reflect altitude changes in plasma temperature and ion composition, over more than a solar cycle. The approach is to determine the locations of mid-latitude O +/H + transition altitudes deduced by fitting the topside N e profiles to modeled H + and O + profiles using the base electron temperatures and constant temperature gradients as variables.