Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Radial and Longitudinal Variation of a Magnetic Cloud: ACE, Wind,
  ARTEMIS and Juno Observations   We present observations of the same magnetic cloud made near Earth by the
Advance Composition Explorer (ACE), Wind, and the Acceleration, Reconnection,
Turbulence and Electrodynamics of the Moon's Interaction with the Sun (ARTEMIS)
mission comprising the Time History of Events and Macroscale Interactions
during Substorms (THEMIS) B and THEMIS C spacecraft, and later by Juno at a
distance of 1.2 AU. The spacecraft were close to radial alignment throughout
the event, with a longitudinal separation of $3.6^{\circ}$ between Juno and the
spacecraft near Earth. The magnetic cloud likely originated from a filament
eruption on 22 October 2011 at 00:05 UT, and caused a strong geomagnetic storm
at Earth commencing on 24 October. Observations of the magnetic cloud at each
spacecraft have been analysed using Minimum Variance Analysis and two flux rope
fitting models, Lundquist and Gold-Hoyle, to give the orientation of the flux
rope axis. We explore the effect different trailing edge boundaries have on the
results of each analysis method, and find a clear difference between the
orientations of the flux rope axis at the near-Earth spacecraft and Juno,
independent of the analysis method. The axial magnetic field strength and the
radial width of the flux rope are calculated using both observations and
fitting parameters and their relationship with heliocentric distance is
investigated. Differences in results between the near-Earth spacecraft and Juno
are attributed not only to the radial separation, but to the small longitudinal
separation which resulted in a surprisingly large difference in the in situ
observations between the spacecraft. This case study demonstrates the utility
of Juno cruise data as a new opportunity to study magnetic clouds beyond 1 AU,
and the need for caution in future radial alignment studies.

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The categories of this paper are: q-fin
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The categories of this paper are: stat
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
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The categories of this paper are: bayes-an
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The categories of this paper are: adap-org
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The categories of this paper are: math-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: nucl-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: econ
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The categories of this paper are: ao-sci
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The categories of this paper are: hep-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: mtrl-th
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The categories of this paper are: cs