Event Title

Ionospheric Control of Magnetic Reconnection

Location

Yosemite National Park

Start Date

2-11-2014 5:10 PM

End Date

2-11-2014 5:40 PM

Description

The ionosphere influences dayside and nightside magnetic reconnection through its electrodynamic and inertial couplings to the magnetosphere. The distribution of high-speed plasma flows observed at distances of 10-30 earth radii in the magnetotail neutral sheet is highly skewed toward the premidnight sector due to electrodynamic coupling. These flows are a product of nightside reconnection, and numerical simulations indicate that the primary causal agent for their observed asymmetry is the meridional gradient in the ionospheric Hall conductance. Ionospheric outflows also have the capacity to change the dynamics and rate of nightside reconnection. Periodic substorms are observed for strong and steady solar wind driving in many data sets, but they occur in geospace simulations only when ionospheric outflows are included. When circulated through the plasmasheet and energized to populate the ring current, ions of ionospheric origin can also inflate the dayside magnetosphere, particularly during storm conditions. The result is a change in the shape of the magnetopause boundary, in the balance between convective and reconnective transport of magnetic flux through the magnetosheath and in the cross polar cap potential. These effects and their physical origins are demonstrated using results from global simulations.

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Feb 11th, 5:10 PM Feb 11th, 5:40 PM

Ionospheric Control of Magnetic Reconnection

Yosemite National Park

The ionosphere influences dayside and nightside magnetic reconnection through its electrodynamic and inertial couplings to the magnetosphere. The distribution of high-speed plasma flows observed at distances of 10-30 earth radii in the magnetotail neutral sheet is highly skewed toward the premidnight sector due to electrodynamic coupling. These flows are a product of nightside reconnection, and numerical simulations indicate that the primary causal agent for their observed asymmetry is the meridional gradient in the ionospheric Hall conductance. Ionospheric outflows also have the capacity to change the dynamics and rate of nightside reconnection. Periodic substorms are observed for strong and steady solar wind driving in many data sets, but they occur in geospace simulations only when ionospheric outflows are included. When circulated through the plasmasheet and energized to populate the ring current, ions of ionospheric origin can also inflate the dayside magnetosphere, particularly during storm conditions. The result is a change in the shape of the magnetopause boundary, in the balance between convective and reconnective transport of magnetic flux through the magnetosheath and in the cross polar cap potential. These effects and their physical origins are demonstrated using results from global simulations.