Modeling Interplanetary Expansion and Deformation of CMEs with ANTEATR-PARADE I: Relative Contribution of Different Forces. (arXiv:2011.06030v3 [astro-ph.SR] UPDATED)

Modeling Interplanetary Expansion and Deformation of CMEs with ANTEATR-PARADE I: Relative Contribution of Different Forces. (arXiv:2011.06030v3 [astro-ph.SR] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Kay_C/0/1/0/all/0/1">C. Kay</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nieves_Chinchilla_T/0/1/0/all/0/1">T. Nieves-Chinchilla</a>

Coronal Mass Ejections (CMEs) are key drivers of space weather activity but
most predictions have been limited to the expected arrival time of a CME,
rather than the internal properties that affect the severity of an impact. Many
properties, such as the magnetic field density and mass density, follow
conservation laws and vary systematically with changes in the size of a CME. We
present ANTEATR-PARADE, the newest version of the ANTEATR arrival time model,
which now includes physics-driven changes in the size and shape of both the
CME’s central axis and its cross section. Internal magnetic and thermal and
external drag forces affect the acceleration of the CME in different
directions, inducing asymmetries between the radial and perpendicular
directions. These improvements should lead to more realistic CME velocities,
both bulk and expansion, sizes and shapes, and internal properties. We present
the model details, an initial illustration of the general behavior, and a study
of the relative importance of the different forces. The model shows a pancaking
of both the cross section and central axis of the CME so that their radial
extent becomes smaller than their extent in the perpendicular direction. We
find that the initial velocities, drag, any form of cross section expansion,
and the precise form of thermal expansion have strong effects. The results are
less sensitive to axial forces and the specific form of the cross section
expansion.

Coronal Mass Ejections (CMEs) are key drivers of space weather activity but
most predictions have been limited to the expected arrival time of a CME,
rather than the internal properties that affect the severity of an impact. Many
properties, such as the magnetic field density and mass density, follow
conservation laws and vary systematically with changes in the size of a CME. We
present ANTEATR-PARADE, the newest version of the ANTEATR arrival time model,
which now includes physics-driven changes in the size and shape of both the
CME’s central axis and its cross section. Internal magnetic and thermal and
external drag forces affect the acceleration of the CME in different
directions, inducing asymmetries between the radial and perpendicular
directions. These improvements should lead to more realistic CME velocities,
both bulk and expansion, sizes and shapes, and internal properties. We present
the model details, an initial illustration of the general behavior, and a study
of the relative importance of the different forces. The model shows a pancaking
of both the cross section and central axis of the CME so that their radial
extent becomes smaller than their extent in the perpendicular direction. We
find that the initial velocities, drag, any form of cross section expansion,
and the precise form of thermal expansion have strong effects. The results are
less sensitive to axial forces and the specific form of the cross section
expansion.

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