A numerical model of the ionospheric signatures of time-varying magnetic reconnection: III. Quasi-instantaneous convection responses in the Cowley-Lockwood paradigm
Using a numerical implementation of the cowlock92 model of flow excitation in the magnetosphere-ionosphere (MI) system, we show that both an expanding (on a ~12-min timescale) and a quasi-instantaneous response in ionospheric convection to the onset of magnetopause reconnection can be accommodat...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2006-05-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/24/961/2006/angeo-24-961-2006.pdf |
| Summary: | Using a numerical implementation of the cowlock92 model of
flow excitation in the magnetosphere-ionosphere (MI) system, we
show that both an expanding (on a ~12-min timescale) and a
quasi-instantaneous response in ionospheric convection to the onset
of magnetopause reconnection can be accommodated by the
Cowley-Lockwood conceptual framework. This model has a key feature
of time dependence, necessarily considering the history of the
coupled MI system. We show that a residual flow, driven by prior
magnetopause reconnection, can produce a quasi-instantaneous global
ionospheric convection response; perturbations from an equilibrium
state may also be present from tail reconnection, which will
superpose constructively to give a similar effect. On the other
hand, when the MI system is relatively free of pre-existing flow, we
can most clearly see the expanding nature of the response. As the
open-closed field line boundary will frequently be in motion from
such prior reconnection (both at the dayside magnetopause and in the
cross-tail current sheet), it is expected that there will usually be
some level of combined response to dayside reconnection. |
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| ISSN: | 0992-7689 1432-0576 |