Observations of the F region height redistribution in the storm‐time ionosphere over Europe and the USA using GPS imaging

[1] Ionospheric imaging with GPS provides a near-global view of the three-dimensional time-evolving ionosphere. This is of particular interest during storms. The focus of this paper is on the height redistribution of the plasma and in particular the longitudinal and latitudinal variations in the time of plasma uplifts. Three storms, 15 July 2000, 30 October 2003 and 20 November 2003, are studied here. Dramatic elevation of the F layer by more than one hundred kilometers was seen in the images during daytime over Europe and the USA for all three storms. All three showed an east-west time delay of around one hour in the peak-height elevation over some 85° longitude. The 20 November 2003 storm also showed a north-south time delay in the change in the F-region height with the uplift seen first at high latitudes and then low latitudes. Independent evidence from other instruments and techniques are provided as supporting evidence that the peak-height uplifts occurred. Candidate mechanisms of the peak height changes are electric fields and neutral winds and the roles of these drivers will be investigated in future modelling studies.