Helium Abundance Decrease in ICMEs in 23–24 Solar Cycles
Based on the OMNI database, the influence of the solar activity decrease in solar cycles (SCs) 23–24 on the behavior of the relative helium ions abundance N<sub>α</sub>/N<sub>p</sub> inside interplanetary coronal mass ejections (ICMEs) is investigated. The dependences of the...
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MDPI AG
2022-10-01
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| Series: | Universe |
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| Online Access: | https://www.mdpi.com/2218-1997/8/11/557 |
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| author | Alexander A. Khokhlachev Yuri I. Yermolaev Irina G. Lodkina Maria O. Riazantseva Liudmila S. Rakhmanova |
| author_facet | Alexander A. Khokhlachev Yuri I. Yermolaev Irina G. Lodkina Maria O. Riazantseva Liudmila S. Rakhmanova |
| author_sort | Alexander A. Khokhlachev |
| collection | DOAJ |
| description | Based on the OMNI database, the influence of the solar activity decrease in solar cycles (SCs) 23–24 on the behavior of the relative helium ions abundance N<sub>α</sub>/N<sub>p</sub> inside interplanetary coronal mass ejections (ICMEs) is investigated. The dependences of the helium abundance on the plasma and interplanetary magnetic field parameters in the epoch of high solar activity (SCs 21–22) and the epoch of low activity (SCs 23–24) are compared. It is shown that N<sub>α</sub>/N<sub>p</sub> significantly decreased in SCs 23–24 compared to SCs 21–22. The general trends of the dependences have not changed with the change of epoch, but the helium abundance dependences on some parameters (for example, the magnitude of the interplanetary magnetic field) have become weaker in the epoch of low activity than they were in the epoch of high activity. In addition, the dependence of the helium abundance on the distance from spacecraft to the ICME axis was revealed; the clearest dependence is observed in magnetic clouds. The N<sub>α</sub>/N<sub>p</sub> maximum is measured at the minimum distance, which confirms the hypothesis of the existence of a helium-enriched electric current inside an ICME. |
| first_indexed | 2024-03-09T18:35:36Z |
| format | Article |
| id | doaj.art-c54d8f5a2761407dad06222dda392632 |
| institution | Directory Open Access Journal |
| issn | 2218-1997 |
| language | English |
| last_indexed | 2024-03-09T18:35:36Z |
| publishDate | 2022-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Universe |
| spelling | doaj.art-c54d8f5a2761407dad06222dda3926322023-11-24T07:11:56ZengMDPI AGUniverse2218-19972022-10-0181155710.3390/universe8110557Helium Abundance Decrease in ICMEs in 23–24 Solar CyclesAlexander A. Khokhlachev0Yuri I. Yermolaev1Irina G. Lodkina2Maria O. Riazantseva3Liudmila S. Rakhmanova4Space Research Institute, Russian Academy of Sciences, 117997 Moscow, RussiaSpace Research Institute, Russian Academy of Sciences, 117997 Moscow, RussiaSpace Research Institute, Russian Academy of Sciences, 117997 Moscow, RussiaSpace Research Institute, Russian Academy of Sciences, 117997 Moscow, RussiaSpace Research Institute, Russian Academy of Sciences, 117997 Moscow, RussiaBased on the OMNI database, the influence of the solar activity decrease in solar cycles (SCs) 23–24 on the behavior of the relative helium ions abundance N<sub>α</sub>/N<sub>p</sub> inside interplanetary coronal mass ejections (ICMEs) is investigated. The dependences of the helium abundance on the plasma and interplanetary magnetic field parameters in the epoch of high solar activity (SCs 21–22) and the epoch of low activity (SCs 23–24) are compared. It is shown that N<sub>α</sub>/N<sub>p</sub> significantly decreased in SCs 23–24 compared to SCs 21–22. The general trends of the dependences have not changed with the change of epoch, but the helium abundance dependences on some parameters (for example, the magnitude of the interplanetary magnetic field) have become weaker in the epoch of low activity than they were in the epoch of high activity. In addition, the dependence of the helium abundance on the distance from spacecraft to the ICME axis was revealed; the clearest dependence is observed in magnetic clouds. The N<sub>α</sub>/N<sub>p</sub> maximum is measured at the minimum distance, which confirms the hypothesis of the existence of a helium-enriched electric current inside an ICME.https://www.mdpi.com/2218-1997/8/11/557solar windinterplanetary coronal mass ejectionmagnetic cloudhelium abundance |
| spellingShingle | Alexander A. Khokhlachev Yuri I. Yermolaev Irina G. Lodkina Maria O. Riazantseva Liudmila S. Rakhmanova Helium Abundance Decrease in ICMEs in 23–24 Solar Cycles Universe solar wind interplanetary coronal mass ejection magnetic cloud helium abundance |
| title | Helium Abundance Decrease in ICMEs in 23–24 Solar Cycles |
| title_full | Helium Abundance Decrease in ICMEs in 23–24 Solar Cycles |
| title_fullStr | Helium Abundance Decrease in ICMEs in 23–24 Solar Cycles |
| title_full_unstemmed | Helium Abundance Decrease in ICMEs in 23–24 Solar Cycles |
| title_short | Helium Abundance Decrease in ICMEs in 23–24 Solar Cycles |
| title_sort | helium abundance decrease in icmes in 23 24 solar cycles |
| topic | solar wind interplanetary coronal mass ejection magnetic cloud helium abundance |
| url | https://www.mdpi.com/2218-1997/8/11/557 |
| work_keys_str_mv | AT alexanderakhokhlachev heliumabundancedecreaseinicmesin2324solarcycles AT yuriiyermolaev heliumabundancedecreaseinicmesin2324solarcycles AT irinaglodkina heliumabundancedecreaseinicmesin2324solarcycles AT mariaoriazantseva heliumabundancedecreaseinicmesin2324solarcycles AT liudmilasrakhmanova heliumabundancedecreaseinicmesin2324solarcycles |