Publication
Weak Magnetic Storms Can Modulate Ionosphere‐Plasmasphere Interaction Significantly: Mechanisms and Manifestations at Mid‐Latitudes
Publisher:
American Geophysical Union (AGU)
Date:
11-2019
DOI:
10.1029/2019JA027076
Abstract: A comprehensive study of the response of the ionosphere‐plasmasphere system at mid‐latitudes to weak (Dst min −50 nT) magnetic storms is presented. For the first time, it is shown that weak magnetic disturbances can lead to significant modulation of ionosphere‐plasmasphere H + ion fluxes. It is found that this modulation is caused by the enhancements/reductions of the topside O + ion density, which is induced by F2‐layer peak height rise and fall during the storms. The F2‐layer motion is caused by thermospheric wind changes and by a penetration electric field. Both drivers are closely related to the changes in the B z component of interplanetary magnetic field. The most prominent manifestation of the H + ion flux modulation is strong changes in H + ion fraction in the topside ionosphere. This study also indicates that the NRLMSISE‐00 model provides the correct relative changes of neutral H density during weak magnetic storms and also that there is a compelling need to include geomagnetic activity indices, in addition to solar activity (F 10.7 ), as input parameters to empirical topside ionosphere models.