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ABSTRACT
Magnetic
reconnection is often suggested as an important process
in space plasma systems. It can change the topology of the magnetic
field, which allows the solar wind plasma to penetrate into the
Earth’s
magnetosphere. It also converts magnetic energy into the kinetic
and thermal energy, which may play a role in solar coronal heating,
and reconnection is an important aspect of geomagnetic substorms.
A lot of the attention has focused on the plasma and energy transport
into the magnetosphere. It is interesting to note, that this plasma
entry is associated with dramatic entropy S=p/ρ
γ increase,
which indicates the existence of strong non-adiabatic heating during
the entry process. Observations indicate that the plasma entropy
increases by 2 orders of magnitude during the transport from solar
wind into the earth magnetosphere. Therefore it is important to
examine whether magnetic reconnection can provide sufficient
non-adiabatic heating to explain the observed plasma properties
and to identify plasma conditions that allow strong nonadiabatic
heating. This presentation examines the production of entropy during
magnetic reconnection in MHD and Hall MHD simulation, respectively.
It is demonstrated that the entropy can indeed strongly increase
during magnetic reconnection provided that the plasma beta, i.e.,
the ratio of thermal to magnetic energy density is is small.
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