Statistical Study of Solar Wind, Magnetosheath and Magnetotail Plasma
and Field Properties: 12+ Years of THEMIS Observations and MHD
Simulations
Abstract
The solar wind plasma is a major plasma source for the Earth’s
magnetosphere,
which has a strong influence on the magnetotail plasma and field
properties.
The relative importance of different plasma entry mechanisms and
pathways is largely determined by the solar wind conditions. Therefore,
the spatial and temporal dependence of magnetotail plasma and field
properties under different kinds of solar wind conditions is critically
important for understanding the Earth’s magnetosphere.
This study presents a statistical study of fundamental magnetotail
plasma properties in a normalized reference frame by utilizing 12+ years
of data from NASA’s Time History of Events and Macroscale Interactions
during Substorms (THEMIS) -mission. These statistical maps are mostly in
agreement with the MHD runs from the CCMC BATS-R-US model, but some
features in the maps can be explained by kinetic particle physics, not
present in the MHD. The results are also used to investigate the
presence of any magnetotail plasma parameter asymmetries and their
possible causes.