Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The solar wind disappearance event of 11 May 1999: source region
  evolution   Context. A recent, detailed study of the well-known solar wind disappearance
event of 11 May 1999 traced its origin to a coronal hole (CH) lying adjacent to
a large active region (AR), AR8525 in Carrington rotation 1949. The AR was
located at central meridian on 05 May 1999 when the flows responsible for this
event began. We examine the evolution of the AR-CH complex during 5-6 May 1999
to study the changes that apparently played a key role in causing this
disappearance event. Aims. To study the evolution of the solar source region of
the disappearance event of 11 May 1999. Methods. Using images from the Soft
X-ray Telescope (SXT), the Extreme-ultraviolet Imaging Telescope (EIT) and the
Michelson Doppler Imager (MDI) to examine the evolution of the CH and AR
complex at the source region of the disappearance event. Results. We find a
dynamic evolution taking place in the CH-AR boundary at the source region of
the disappearance event of 11 May 1999. This evolution, which is found to
reduce the area of the CH, is accompanied by the formation of new loops in EUV
images that are spatially and temporally correlated with emerging flux regions
as seen in MDI data. Conclusions. In the period leading up to the disappearance
event of 11 May 1999, our observations, during quiet solar conditions and in
the absence of CMEs, provide the first clear evidence for Sun-Earth connection
originating from an evolving AR-CH region located at central meridian. With the
exception of corotating interacting regions (CIR), these observations provide
the first link between the Sun and space weather effects at 1 AU, arising from
non-explosive solar events.

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The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
3
The categories of this paper are: physics
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
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The categories of this paper are: supr-con
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-lat
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The categories of this paper are: cmp-lg
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The categories of this paper are: cond-mat
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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: stat
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The categories of this paper are: atom-ph
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The categories of this paper are: quant-ph