Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fast degradation of the circular flare ribbon on 2014 August 24   The separation and elongation motions of solar flare ribbons have extensively
been investigated. The degradation and disappearance of ribbons have rarely
been explored. In this paper, we report our multiwavelength observations of a
C5.5 circular-ribbon flare associated with two jets (jet1 and jet2) on 2014
August 24, focusing on the fast degradation of the outer circular ribbon (CR).
The flare, consisting of a short inner ribbon (IR) and outer CR, was triggered
by the eruption of a minifilament. The brightness of IR and outer CR reached
their maxima simultaneously at $\sim$04:58 UT in all AIA wavelengths.
Subsequently, the short eastern part of CR faded out quickly in 1600 {\AA} but
gradually in EUV wavelengths. The long western part of CR degraded in the
counterclockwise direction and experienced a deceleration. The degradation was
distinctly divided into two phases: phase I with faster apparent speeds
(58$-$69 km s$^{-1}$) and phase II with slower apparent speeds (29$-$35 km
s$^{-1}$). The second phase stopped at $\sim$05:10 UT when the western CR
totally disappeared. Besides the outward propagation of jet1, the jet spire
experienced untwisting motion in the counterclockwise direction during
04:55$-$05:00 UT. We conclude that the event can be explained by the breakout
jet model. The coherent brightenings of the IR and CR at $\sim$04:58 UT may
result from the impulsive interchange reconnection near the null point, whereas
sub-Alfv\'{e}nic slipping motion of the western CR in the counterclockwise
direction indicates the occurrence of slipping magnetic reconnection. Another
possible explanation of the quick disappearance of the hot loops connecting to
the western CR is that they are simply reconnected sequentially without the
need for significant slippage after the null point reconnection.

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The categories of this paper are: acc-phys
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The categories of this paper are: q-alg
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The categories of this paper are: adap-org
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The categories of this paper are: plasm-ph
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The categories of this paper are: hep-th
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The categories of this paper are: dg-ga
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The categories of this paper are: eess
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The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
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The categories of this paper are: q-bio
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The categories of this paper are: comp-gas
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The categories of this paper are: ao-sci
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The categories of this paper are: math
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The categories of this paper are: supr-con
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat