Weak ionization of the global ionosphere in solar cycle 24
Following prolonged and extremely quiet solar activity from 2008 to 2009, the 24th solar cycle started slowly. It has been almost 5 years since then. The measurement of ionospheric critical frequency (<i>fo</i>F2) shows the fact that solar activity has been significantly lower in the...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2014-07-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/32/809/2014/angeo-32-809-2014.pdf |
| _version_ | 1811263486410358784 |
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| author | Y. Q. Hao H. Shi Z. Xiao Z. Xiao D. H. Zhang D. H. Zhang |
| author_facet | Y. Q. Hao H. Shi Z. Xiao Z. Xiao D. H. Zhang D. H. Zhang |
| author_sort | Y. Q. Hao |
| collection | DOAJ |
| description | Following prolonged and extremely quiet solar activity from 2008 to 2009, the
24th solar cycle started slowly. It has been almost 5 years since then. The
measurement of ionospheric critical frequency (<i>fo</i>F2) shows the fact
that solar activity has been significantly lower in the first half of cycle
24, compared to the average levels of cycles 19 to 23; the data of global
average total electron content (<span style="border-top: 1px solid #000; color: #000;">TEC</span>) confirm that the
global ionosphere around the cycle 24 peak is much more weakly ionized, in
contrast to cycle 23. The weak ionization has been more notable since the
year 2012, when both the ionosphere and solar activity were expected to be
approaching their maximum level. The undersupply of solar extreme ultraviolet
(EUV) irradiance somewhat continues after the 2008–2009 minimum, and is
considered to be the main cause of the weak ionization. It further implies
that the thermosphere and ionosphere in the first solar cycle of this
millennium would probably differ from what we have learned from the previous
cycles of the space age. |
| first_indexed | 2024-04-12T19:46:11Z |
| format | Article |
| id | doaj.art-1ca71e616c75491984e12326e0178978 |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-04-12T19:46:11Z |
| publishDate | 2014-07-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-1ca71e616c75491984e12326e01789782022-12-22T03:18:57ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762014-07-013280981610.5194/angeo-32-809-2014Weak ionization of the global ionosphere in solar cycle 24Y. Q. Hao0H. Shi1Z. Xiao2Z. Xiao3D. H. Zhang4D. H. Zhang5Department of Geophysics, Peking University, Beijing, ChinaDepartment of Geophysics, Peking University, Beijing, ChinaDepartment of Geophysics, Peking University, Beijing, ChinaState Key Laboratory of Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing, ChinaDepartment of Geophysics, Peking University, Beijing, ChinaState Key Laboratory of Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing, ChinaFollowing prolonged and extremely quiet solar activity from 2008 to 2009, the 24th solar cycle started slowly. It has been almost 5 years since then. The measurement of ionospheric critical frequency (<i>fo</i>F2) shows the fact that solar activity has been significantly lower in the first half of cycle 24, compared to the average levels of cycles 19 to 23; the data of global average total electron content (<span style="border-top: 1px solid #000; color: #000;">TEC</span>) confirm that the global ionosphere around the cycle 24 peak is much more weakly ionized, in contrast to cycle 23. The weak ionization has been more notable since the year 2012, when both the ionosphere and solar activity were expected to be approaching their maximum level. The undersupply of solar extreme ultraviolet (EUV) irradiance somewhat continues after the 2008–2009 minimum, and is considered to be the main cause of the weak ionization. It further implies that the thermosphere and ionosphere in the first solar cycle of this millennium would probably differ from what we have learned from the previous cycles of the space age.https://www.ann-geophys.net/32/809/2014/angeo-32-809-2014.pdf |
| spellingShingle | Y. Q. Hao H. Shi Z. Xiao Z. Xiao D. H. Zhang D. H. Zhang Weak ionization of the global ionosphere in solar cycle 24 Annales Geophysicae |
| title | Weak ionization of the global ionosphere in solar cycle 24 |
| title_full | Weak ionization of the global ionosphere in solar cycle 24 |
| title_fullStr | Weak ionization of the global ionosphere in solar cycle 24 |
| title_full_unstemmed | Weak ionization of the global ionosphere in solar cycle 24 |
| title_short | Weak ionization of the global ionosphere in solar cycle 24 |
| title_sort | weak ionization of the global ionosphere in solar cycle 24 |
| url | https://www.ann-geophys.net/32/809/2014/angeo-32-809-2014.pdf |
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