Magnetic flux density in the heliosphere through several solar cycles
Abstract
We studied the magnetic flux density carried by solar wind to various locations in the heliosphere, covering a heliospheric distance range of 0.3-5.4 AU and a heliolatitudinal range from 80° south to 80° north. Distributions of the radial component of the magnetic field, B{sub R} , were determined over long intervals from the Helios, ACE, STEREO, and Ulysses missions, as well as from using the 1 AU OMNI data set. We show that at larger distances from the Sun, the fluctuations of the magnetic field around the average Parker field line distort the distribution of B{sub R} to such an extent that the determination of the unsigned, open solar magnetic flux density from the average (|B{sub R} |) is no longer justified. We analyze in detail two methods for reducing the effect of fluctuations. The two methods are tested using magnetic field and plasma velocity measurements in the OMNI database and in the Ulysses observations, normalized to 1 AU. It is shown that without such corrections for the fluctuations, the magnetic flux density measured by Ulysses around the aphelion phase of the orbit is significantly overestimated. However, the matching between the in-ecliptic magnetic flux density at 1 AU (OMNI data)more »
- Authors:
-
- Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary)
- Publication Date:
- OSTI Identifier:
- 22348151
- Resource Type:
- Journal Article
- Journal Name:
- Astrophysical Journal
- Additional Journal Information:
- Journal Volume: 781; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CORRECTIONS; DISTRIBUTION; FLUCTUATIONS; FLUX DENSITY; HELIOSPHERE; MAGNETIC FIELDS; MAGNETIC FLUX; ORBITS; PLASMA; RECREATIONAL AREAS; SOLAR CYCLE; SOLAR WIND; SUN; VELOCITY
Citation Formats
Erdős, G., and Balogh, A., E-mail: erdos.geza@wigner.mta.hu. Magnetic flux density in the heliosphere through several solar cycles. United States: N. p., 2014.
Web. doi:10.1088/0004-637X/781/1/50.
Erdős, G., & Balogh, A., E-mail: erdos.geza@wigner.mta.hu. Magnetic flux density in the heliosphere through several solar cycles. United States. https://doi.org/10.1088/0004-637X/781/1/50
Erdős, G., and Balogh, A., E-mail: erdos.geza@wigner.mta.hu. 2014.
"Magnetic flux density in the heliosphere through several solar cycles". United States. https://doi.org/10.1088/0004-637X/781/1/50.
@article{osti_22348151,
title = {Magnetic flux density in the heliosphere through several solar cycles},
author = {Erdős, G. and Balogh, A., E-mail: erdos.geza@wigner.mta.hu},
abstractNote = {We studied the magnetic flux density carried by solar wind to various locations in the heliosphere, covering a heliospheric distance range of 0.3-5.4 AU and a heliolatitudinal range from 80° south to 80° north. Distributions of the radial component of the magnetic field, B{sub R} , were determined over long intervals from the Helios, ACE, STEREO, and Ulysses missions, as well as from using the 1 AU OMNI data set. We show that at larger distances from the Sun, the fluctuations of the magnetic field around the average Parker field line distort the distribution of B{sub R} to such an extent that the determination of the unsigned, open solar magnetic flux density from the average (|B{sub R} |) is no longer justified. We analyze in detail two methods for reducing the effect of fluctuations. The two methods are tested using magnetic field and plasma velocity measurements in the OMNI database and in the Ulysses observations, normalized to 1 AU. It is shown that without such corrections for the fluctuations, the magnetic flux density measured by Ulysses around the aphelion phase of the orbit is significantly overestimated. However, the matching between the in-ecliptic magnetic flux density at 1 AU (OMNI data) and the off-ecliptic, more distant, normalized flux density by Ulysses is remarkably good if corrections are made for the fluctuations using either method. The main finding of the analysis is that the magnetic flux density in the heliosphere is fairly uniform, with no significant variations having been observed either in heliocentric distance or heliographic latitude.},
doi = {10.1088/0004-637X/781/1/50},
url = {https://www.osti.gov/biblio/22348151},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 781,
place = {United States},
year = {Mon Jan 20 00:00:00 EST 2014},
month = {Mon Jan 20 00:00:00 EST 2014}
}