J/A+A/675/A196 Trans-Heliospheric Survey. Radial trends (Maruca+, 2023)
The Trans-Heliospheric Survey:
Radial trends in plasma parameters across the heliosphere.
Maruca B.A., Qudsi R.A., Alterman B.L., Walsh B.M., Korreck K.E.,
Verscharen D., Bandyopadhyay R., Chhiber R., Chasapis A., Parashar T.N.,
Matthaeus W.H., Goldstein M.L.
<Astron. Astrophys. 675, A196 (2023)>
=2023A&A...675A.196M 2023A&A...675A.196M (SIMBAD/NED BibCode)
ADC_Keywords: Solar system ; Sun
Keywords: Sun: heliosphere - Sun: solar wind - Sun: corona
Abstract:
Though the solar wind is characterized by spatial and temporal
variability across a wide range of scales, long-term averages
of in situ measurements have revealed clear radial trends: changes in
average values of basic plasma parameters (e.g., density, temperature,
and speed) and a magnetic field with a distance from the Sun.
To establish our current understanding of the solar wind's average
expansion through the heliosphere, data from multiple spacecraft
needed to be combined and standardized into a single dataset.
In this study, data from twelve heliospheric and planetary spacecraft
- Parker Solar Probe (PSP), Helios 1 and 2, Mariner 2 and 10,
Ulysses, Cassini, Pioneer 10 and 11, New Horizons, and Voyager 1 and 2
- were compiled into a dataset spanning over three orders of
magnitude in heliocentric distance. To avoid introducing artifacts
into this composite dataset, special attention was given to the solar
cycle, spacecraft heliocentric elevation, and instrument calibration.
The radial trend in each parameter was found to be generally well
described by a power-law fit, though up to two break points were
identified in each fit.
These radial trends are publicly released here to benefit research
groups in the validation of global heliospheric simulations and in the
development of new deep-space missions such as Interstellar Probe.
Description:
This work, the Trans-Heliospheric Survey, constitutes one of the
most comprehensive analyses to date of in situ solar-wind
observations: data from twelve spacecraft (Table 1) spanning three
orders of magnitude in distance from the Sun. The resulting radial
trends (Figures 1 to 7) elucidate the 'big picture' of solarwind
expansion.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 85 12 Datasets used in this study
fig1_b.dat 62 76 Figure 1: magnetic-field strength (k=B)
fig2np.dat 62 76 Figure 2: proton number-density (k=np)
fig3vp.dat 62 76 Figure 3: proton bulk speed (k=vp)
fig4tp.dat 62 76 Figure 4: proton scalar temperature (k=Tp)
fig5va.dat 62 76 Figure 5: proton Alfven speed (k=vA)
fig6na.dat 62 76 Figure 6: proton Alfven number (k=NA)
fig7bp.dat 62 76 Figure 7: proton scalar beta (k=betap)
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Inst Spacecraft
14 A1 --- n_Inst [a] Note on Inst (1)
16- 19 I4 yr TempCov1 Temporal coverage
20 A1 --- --- [-]
21- 24 I4 yr TempCov2 ? Temporal coverage
25 A1 --- n_TempCov2 [bc] Note on TempCov (1)
27- 31 F5.2 au RadCov1 Radial coverage [au]
32 A1 --- n_RadCov1 [b] Note on RadCov1 (1)
33 A1 --- --- [-]
34- 39 F6.2 au RadCov2 Radial coverage [au]
40 A1 --- n_RadCov2 [bc] Note on RadCov2 (1)
42- 85 A44 --- Source Data source
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Note (1): Notes as follows:
a = Ongoing mission
b = Limit of publicly available data at time of access
c = Artificial limit on radial coverage imposed for this study
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Byte-by-byte Description of file: fig*.dat
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Bytes Format Units Label Explanations
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1- 8 E8.3 au r Median distance from Sun
10- 17 E8.3 --- k10 10th percentile in k/<k_⊕>
19- 26 E8.3 --- k25 25th percentile in k/<k_⊕>
28- 35 E8.3 --- k50 50th percentile in k/<k_⊕>
37- 44 E8.3 --- k75 75th percentile in k/<k_⊕>
46- 53 E8.3 --- k90 90th percentile in k/<k_⊕>
55- 62 E8.3 --- Nint Number of intervals
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Acknowledgements:
Bennett Maruca, bmaruca(at)udel.edu
(End) Patricia Vannier [CDS] 14-Jul-2023