Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measurement of the Open Magnetic Flux in the Inner Heliosphere down to
  0.13AU   (Abridged) Aim: We attempt to determine robust estimates of the heliospheric
magnetic flux ($\Phi_H$) using Parker Solar Probe (PSP) data, analyze how
susceptible this is to overestimation compared to the true open flux
($\Phi_{open}$), assess its dependence on time and space, and compare it to
simple estimates from Potential Field Source Surface (PFSS) models. Methods: We
compare different methods of computation using data from PSP, STEREO A and
Wind. The effects of fluctuations and large scale structure on the estimate are
probed by using measured radial trends to produce synthetic data. Best
estimates are computed as a function of time and space, and compared to
estimates from PFSS models. Results: Radially-varying fluctuations of the HMF
vector and variation of the Parker spiral angle cause the standard metrics of
the mean and mode to evolve with radius independent of the central value about
which the vector fluctuates. This is best mitigated by projecting the vector
into the background Parker spiral direction. Nevertheless, we find a small
enhancement in flux close to 1AU. The fraction of locally inverted field lines
grows with radial distance from the Sun which remains a possible physical
reason for this excess, but is negligible at PSP`s perihelia. Similarly, the
impact of fluctuations in general is much reduced at PSP`s perihelia. The
overall best estimate is ~2.5 nT AU2 . No strong dependence on latitude or
longitude is apparent. The PFSS models predict lower values from 1.2 to 1.8 nT
AU2. Conclusions: The heliospheric flux is robustly estimated relative to a
mean Parker spiral direction at PSP`s perihelia where the decay of fluctuations
and weakening importance of local flux inversions means $\Phi_H$ ~
$\Phi_{open}$. Despite this, the estimate remains too high to be explained by
PFSS models, supporting the idea that coronal models underestimate the open
magnetic flux.

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The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
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The categories of this paper are: dg-ga
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The categories of this paper are: plasm-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: cs
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The categories of this paper are: q-alg
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The categories of this paper are: q-fin
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The categories of this paper are: hep-ex