Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cassini UVIS Observations of the Io Plasma Torus. IV. Modeling Temporal
  and Azimuthal Variability   In this fourth paper in a series, we present a model of the remarkable
temporal and azimuthal variability of the Io plasma torus observed during the
Cassini encounter with Jupiter. Over a period of three months, the Cassini
Ultraviolet Imaging Spectrograph (UVIS) observed a dramatic variation in the
average torus composition. Superimposed on this long-term variation, is a
10.07-hour periodicity caused by an azimuthal variation in plasma composition
subcorotating relative to System III longitude. Quite surprisingly, the
amplitude of the azimuthal variation appears to be modulated at the beat
frequency between the System III period and the observed 10.07-hour period.
Previously, we have successfully modeled the months-long compositional change
by supposing a factor of three increase in the amount of material supplied to
Io's extended neutral clouds. Here, we extend our torus chemistry model to
include an azimuthal dimension. We postulate the existence of two azimuthal
variations in the number of super-thermal electrons in the torus: a primary
variation that subcorotates with a period of 10.07 hours and a secondary
variation that remains fixed in System III longitude. Using these two hot
electron variations, our model can reproduce the observed temporal and
azimuthal variations observed by Cassini UVIS.

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The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
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The categories of this paper are: atom-ph
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The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org