Heliocentric Distance and Solar Activity Dependence of Sustained Quasi-radial Interplanetary Magnetic Field Occurrence
Planets close to their stars experience an interplanetary magnetic field (IMF) that is dominantly quasi-radial. Our solar system serves as a laboratory to study how the occurrence of quasi-radial IMF varies away from the star and under different stellar activities. Furthermore, on time and spatial s...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ace328 |
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| author | Brandon L. Burkholder Li-Jen Chen Norberto Romanelli Dave Sibeck Jaye Verniero Gina A. DiBraccio Daniel Gershman Menelaos Sarantos |
| author_facet | Brandon L. Burkholder Li-Jen Chen Norberto Romanelli Dave Sibeck Jaye Verniero Gina A. DiBraccio Daniel Gershman Menelaos Sarantos |
| author_sort | Brandon L. Burkholder |
| collection | DOAJ |
| description | Planets close to their stars experience an interplanetary magnetic field (IMF) that is dominantly quasi-radial. Our solar system serves as a laboratory to study how the occurrence of quasi-radial IMF varies away from the star and under different stellar activities. Furthermore, on time and spatial scales relevant to magnetospheric physics, solar wind variability prevails in the form of structures generated both at the Sun and locally in the interplanetary space. The stationary Parker spiral model only approximates the large-scale structure of the IMF. Deviations from the Parker spiral often result in strongly radial magnetic fields that give rise to kinetic foreshock turbulence, which in turn can impact planetary magnetospheres. The relative significance of this type of interaction can be estimated statistically based on the occurrence rate of cases where the IMF is directed along the radial direction, leading to the entire day-side magnetosphere being downstream of the ion foreshock. We use observations covering radial distances from 0.1 to 10 au and more than 2 solar cycles to quantify the prevalence of radial IMFs throughout the heliosphere. Near Earth’s orbit, it is found that the occurrence rates of quasi-radial and southward IMF orientations are similar, and that the Pearson correlation coefficient is ${{ \mathcal R }}_{{xy}}\sim -0.7$ calculated between quasi-radial IMF occurrence rate and solar activity. A negative correlation is demonstrated for radial distances extending to at least Mars but not to Saturn. |
| first_indexed | 2024-03-12T03:49:11Z |
| format | Article |
| id | doaj.art-1f554c0d1ce549358f4a6ce48d199ad9 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T03:49:11Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-1f554c0d1ce549358f4a6ce48d199ad92023-09-03T12:30:42ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0195318510.3847/1538-4357/ace328Heliocentric Distance and Solar Activity Dependence of Sustained Quasi-radial Interplanetary Magnetic Field OccurrenceBrandon L. Burkholder0https://orcid.org/0000-0001-8702-5806Li-Jen Chen1https://orcid.org/0000-0002-4768-189XNorberto Romanelli2https://orcid.org/0000-0001-9210-0284Dave Sibeck3Jaye Verniero4Gina A. DiBraccio5Daniel Gershman6https://orcid.org/0000-0003-1304-4769Menelaos Sarantos7https://orcid.org/0000-0003-0728-2971University of Maryland Baltimore County , Baltimore, MD, USA; NASA Goddard Space Flight Center , Greenbelt, MD, USANASA Goddard Space Flight Center , Greenbelt, MD, USANASA Goddard Space Flight Center , Greenbelt, MD, USA; University of Maryland College Park , College Park, MD, USANASA Goddard Space Flight Center , Greenbelt, MD, USANASA Goddard Space Flight Center , Greenbelt, MD, USANASA Goddard Space Flight Center , Greenbelt, MD, USANASA Goddard Space Flight Center , Greenbelt, MD, USANASA Goddard Space Flight Center , Greenbelt, MD, USAPlanets close to their stars experience an interplanetary magnetic field (IMF) that is dominantly quasi-radial. Our solar system serves as a laboratory to study how the occurrence of quasi-radial IMF varies away from the star and under different stellar activities. Furthermore, on time and spatial scales relevant to magnetospheric physics, solar wind variability prevails in the form of structures generated both at the Sun and locally in the interplanetary space. The stationary Parker spiral model only approximates the large-scale structure of the IMF. Deviations from the Parker spiral often result in strongly radial magnetic fields that give rise to kinetic foreshock turbulence, which in turn can impact planetary magnetospheres. The relative significance of this type of interaction can be estimated statistically based on the occurrence rate of cases where the IMF is directed along the radial direction, leading to the entire day-side magnetosphere being downstream of the ion foreshock. We use observations covering radial distances from 0.1 to 10 au and more than 2 solar cycles to quantify the prevalence of radial IMFs throughout the heliosphere. Near Earth’s orbit, it is found that the occurrence rates of quasi-radial and southward IMF orientations are similar, and that the Pearson correlation coefficient is ${{ \mathcal R }}_{{xy}}\sim -0.7$ calculated between quasi-radial IMF occurrence rate and solar activity. A negative correlation is demonstrated for radial distances extending to at least Mars but not to Saturn.https://doi.org/10.3847/1538-4357/ace328Interplanetary magnetic fieldsPlanetary bow shocksSolar cycle |
| spellingShingle | Brandon L. Burkholder Li-Jen Chen Norberto Romanelli Dave Sibeck Jaye Verniero Gina A. DiBraccio Daniel Gershman Menelaos Sarantos Heliocentric Distance and Solar Activity Dependence of Sustained Quasi-radial Interplanetary Magnetic Field Occurrence The Astrophysical Journal Interplanetary magnetic fields Planetary bow shocks Solar cycle |
| title | Heliocentric Distance and Solar Activity Dependence of Sustained Quasi-radial Interplanetary Magnetic Field Occurrence |
| title_full | Heliocentric Distance and Solar Activity Dependence of Sustained Quasi-radial Interplanetary Magnetic Field Occurrence |
| title_fullStr | Heliocentric Distance and Solar Activity Dependence of Sustained Quasi-radial Interplanetary Magnetic Field Occurrence |
| title_full_unstemmed | Heliocentric Distance and Solar Activity Dependence of Sustained Quasi-radial Interplanetary Magnetic Field Occurrence |
| title_short | Heliocentric Distance and Solar Activity Dependence of Sustained Quasi-radial Interplanetary Magnetic Field Occurrence |
| title_sort | heliocentric distance and solar activity dependence of sustained quasi radial interplanetary magnetic field occurrence |
| topic | Interplanetary magnetic fields Planetary bow shocks Solar cycle |
| url | https://doi.org/10.3847/1538-4357/ace328 |
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