Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Solar Modulation of Cosmic Rays during the Declining and Minimum Phases
  of Solar Cycle 23: Comparison with Past Three Solar Cycles   We study solar modulation of galactic cosmic rays (GCRs) during the deep
solar minimum, including the declining phase, of solar cycle 23 and compare the
results of this unusual period with the results obtained during similar phases
of the previous solar cycles 20, 21, and 22. These periods consist of two
epochs each of negative and positive polarities of the heliospheric magnetic
field from the north polar region of the Sun. In addition to cosmic ray data,
we utilize simultaneous solar and interplanetary plasma/field data including
the tilt angle of the heliospheric current sheet. We study the relation between
simultaneous variations in cosmic ray intensity and solar/interplanetary
parameters during the declining and the minimum phases of cycle 23. We compare
these relations with those obtained for the same phases in the three previous
solar cycles. We observe certain peculiar features in cosmic ray modulation
during the minimum of solar cycle 23 including the record high GCR intensity.
We find, during this unusual minimum, that the correlation of GCR intensity is
poor with sunspot number (R = -0.41), better with interplanetary magnetic field
(R = -0.66), still better with solar wind velocity (R = -0.80) and much better
with the tilt angle of the heliospheric current sheet (R = -0.92). In our view,
it is not the diffusion or the drift alone, but the solar wind convection is
the most likely additional effect responsible for the record high GCR intensity
observed during the deep minimum of solar cycle 23.

23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
18
The categories of this paper are: econ
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg