Ionospheric plasma temperatures during 1976–2001 over Millstone Hill Original Research Article

Incoherent scatter measurements have been made since the 1960s over Millstone Hill. Zenith antenna data since 1976 and steerable antenna data since 1980 are now available through the WWW-based Madrigal database system. By analyzing this large volume of data in a systematic way, this paper provides an updated climatology of the ionospheric temperature over Millstone Hill, including diurnal variations, solar activity dependences, and the electron density Ne and electron temperature Te relationship. The daytime Te in the F2-layer is found to increase with the increasing solar activity in summer, and to decrease in winter. The inverse correlation between Ne and Te prevails in winter and equinox but is much less pronounced or even disappears in summer. Based on the database, Millstone Hill incoherent scatter radar models are established, and compared with the latest International Reference Model.