Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The evolution of plasma parameters on a coronal source surface at 2.3 Rs
  during solar minimum   We analyze data from the Solar and Heliospheric Observatory to produce global
maps of coronal outflow velocities and densities in the regions where the solar
wind is undergoing acceleration. The maps use UV and white light coronal data
obtained from the Ultraviolet Coronagraph Spectrometer and the Large Angle
Spectroscopic Coronagraph, respectively, and a Doppler dimming analysis to
determine the mean outflow velocities. The outflow velocities are defined on a
sphere at 2.3 Rs from Sun-center and are organized by Carrington Rotations
during the solar minimum period at the start of solar cycle 23. We use the
outflow velocity and density maps to show that while the solar minimum corona
is relatively stable during its early stages, the shrinkage of the north polar
hole in the later stages leads to changes in both the global areal expansion of
the coronal hole and the derived internal flux tube expansion factors of the
solar wind. The polar hole areal expansion factor and the flux tube expansion
factors (between the coronal base and 2.3 Rs) start out as super-radial but
then they become more nearly radial as the corona progresses away from solar
minimum. The results also support the idea that the largest flux tube expansion
factors are located near the coronal hole/streamer interface, at least during
the deepest part of the solar minimum period.

33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg