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| Titel |
On the solar wind-magnetosphere energy coupling function |
| VerfasserIn |
P. Tenfjord, N. Østgaard |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250064818
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| Zusammenfassung |
| One of the fundamental questions in space physics is to understand how the flow of energy is
transported and distributed in the solar wind-magnetospheric-ionospheric system. There is no
direct method of measuring the energy transfer from the solar wind to the magnetosphere, but
it is well accepted that the transfer is strongly coupled to the southward component of the
Interplanetary Magnetic Field (IMF). During such conditions some of the solar wind
energy will enter the magnetosphere, due to large-scale reconnection processes and
deposit energy in the ionosphere and ring current. The three major sinks in the
Magnetosphere-Ionosphere (MI) system is Ring Current Injection, Joule Heating and Particle
Precipitation. The deposited energy by these sinks can be estimated using ground
based magnetometer data. Over the years several coupling parameters have been
suggested, but still the epsilon parameter from Perrault and Akasofu (1978) based on the
Poynting flux is the most widely used. The epsilon parameter indicates how the
solar wind couples its energy to the magnetosphere. More recent studies have also
included other plasma parameters, e.g. pressure and density, to better balance the
system. Using consistent magnetometer and solar wind data over several months
in the period 1997-2010, we can estimate input (energy coupling function) and
ouput (energy sinks) and assess the validity of various energy coupling functions. |
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