Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Solar surface and atmospheric dynamics: The Photosphere   Various aspects of the magnetism of the quiet sun are reviewed. The
suggestion that a small scale dynamo acting at granular scales generates what
we call the quiet sun fields is studied in some detail. Although dynamo action
has been proved numerically, it is argued that current simulations are still
far from achieving the complexity that might be present on the Sun. We based
this statement not so much on the low magnetic Reynolds numbers used in the
simulations but, above all, in the smallness of the kinetic Reynolds numbers
employed by them. It is argued that the low magnetic Prandtl number at the
solar surface may pose unexpected problems for the identification of the
observed internetwork fields with dynamo action at granular scales. Some form
of turbulent dynamo at bigger (and deeper) scales is favored. The comparison
between the internetwork fields observed by Hinode and the magnetism inferred
from Hanle measurements are converging towards a similar description. They are
both described as randomly oriented, largely transverse fields in the several
hecto-Gauss range. These similarities are ever making more natural to assume
that they are the same. However, and because of the large voids of magnetic
flux observed in the spatial distribution of the internetwork fields, it is
argued that they are not likely to be generated by dynamo action in the
intergranular lanes. It is concluded that if a dynamo is acting at granular
scales, the end product might have not been observed yet at current spatial
resolutions and sensitivities with the Zeeman effect.

8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex