Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Asymmetric Solar Polar Field Reversals   The solar polar fields reverse because magnetic flux from decaying sunspots
moves towards the poles, with a preponderance of flux from the trailing spots.
Let us assume that there is a strong asymmetry in the sense that all activity
is in the Northern Hemisphere, then that excess flux will move to the North
Pole and reverse that pole, while nothing happens in the South. If later on,
there is a lot of activity in the South, then that flux will help reverse the
South Pole. In this way, we get two humps in solar activity and a corresponding
difference in time of reversals. Such difference was first noted by Babcock
(1959) from the very first observation of polar field reversal just after the
maximum of the strongly asymmetric solar cycle 19. At that time, the Southern
Hemisphere was most active before sunspot maximum and the South Pole duly
reversed first, followed by the Northern Hemisphere more than a year later,
when that hemisphere was most active. Solar cycles since then have had the
opposite asymmetry, with the Northern Hemisphere being most active early in the
cycle. Polar field reversals for these cycles have as expected happened first
in the North. This is especially noteworthy for the present solar cycle 24. We
suggest that the association of two peaks of solar activity when separated by
hemispheres with correspondingly different times of polar field reversals is a
general feature of the cycle.

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The categories of this paper are: cond-mat
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The categories of this paper are: math
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The categories of this paper are: econ
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The categories of this paper are: nlin
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The categories of this paper are: atom-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: acc-phys
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The categories of this paper are: stat
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The categories of this paper are: nucl-th
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The categories of this paper are: nucl-ex
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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: q-fin
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The categories of this paper are: funct-an
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-ex