Equatorial fountain effect and dynamo drift signatures from AE-E observations


  • W. R. Coley,

  • J. P. McClure,

  • W. B. Hanson


Vertical and horizontal ion drift velocities for 1977–1979 from the Unified Abstract files of the satellite Atmosphere Explorer E were used in preliminary studies of the behavior of the low-latitude (−20° to 20° dip latitude) F region. Sample diurnal variations obtained during 1978–1979 equinox time periods are very similar to those measured by the incoherent scatter radar at Jicamarca, Peru. Latitude profiles of the vector drift values clearly show the classic “fountain effect” responsible for the Appleton anomaly during the day. Investigation of longitude effects revealed that the average perpendicular (approximately vertical) drift velocity Vperp is independent of longitude, implying that the average east-west electric field is proportional to B and thus is likely derived from classical dynamo winds.