Controlling of the F region plasma structures by the E region conductance in the auroral ionosphere

At high latitudes, the E and F regions of the ionosphere are strongly coupled through nearly vertical magnetic field lines. Direct measurements of such coupling in ionospheric plasma have been quite rare. To simultaneously and directly relate the E and F regions’ plasma structures, we ran a coordinated conjunction campaign between Swarm satellites and Incoherent Scatter Radar (ISR) in Tromsø, Norway, under a moderate geomagnetic storm in late March 2025. For the first time, we quantitatively compare the E region Pedersen conductance with the power spectra of electron density structures and irregularities. The eleven conjunctions considered in the study, show very conclusive results: when the E region conductance is above 3 S, the F region plasma structures tend to have double-slope power spectra. This result can be explained by enhanced cross-field diffusion of small-scale plasma structures when the F region ionosphere is connected to a highly conducting E region below.