Magnetic dipolarizations inside geosynchronous orbit with tailward ion flows
<p>Electromagnetic field and plasma data from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) near-Earth probes are used to investigate magnetic dipolarizations inside geosynchronous orbit on 27 August 2014 during an intense substorm with <span class="i...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-05-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/37/289/2019/angeo-37-289-2019.pdf |
| _version_ | 1819157228239716352 |
|---|---|
| author | X. Sun X. Sun W. W. Liu S. Duan |
| author_facet | X. Sun X. Sun W. W. Liu S. Duan |
| author_sort | X. Sun |
| collection | DOAJ |
| description | <p>Electromagnetic field and plasma data from the Time History of Events and
Macroscale Interactions during Substorms (THEMIS) near-Earth probes are used
to investigate magnetic dipolarizations inside geosynchronous orbit on
27 August 2014 during an intense substorm with <span class="inline-formula">AE<sub>max</sub>∼1000</span> nT. THEMIS-D (TH-D) was located inside geosynchronous orbit around
midnight in the interval from 09:25 to 09:55 UT. During this period, two
distinct magnetic dipolarizations with tailward ion flows are observed by
TH-D. The first one is indicated by the magnetic elevation angle increase from
15 to 25<span class="inline-formula"><sup>∘</sup></span> around 09:30:40 UT. The tailward perpendicular velocity is
<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow><msub><mi>V</mi><mrow><mo>⊥</mo><mi mathvariant="normal">x</mi></mrow></msub><mo>∼</mo><mo>-</mo><mn mathvariant="normal">50</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="50pt" height="12pt" class="svg-formula" dspmath="mathimg" md5hash="826bf632c156da00cbb31ba70094db72"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="angeo-37-289-2019-ie00001.svg" width="50pt" height="12pt" src="angeo-37-289-2019-ie00001.png"/></svg:svg></span></span> km s<span class="inline-formula"><sup>−1</sup></span>. The second one is presented by
the elevation angle increase from 25 to 45<span class="inline-formula"><sup>∘</sup></span> around 09:36 UT, and the
tailward perpendicular velocity is <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M6" display="inline" overflow="scroll" dspmath="mathml"><mrow><msub><mi>V</mi><mrow><mo>⊥</mo><mi mathvariant="normal">x</mi></mrow></msub><mo>∼</mo><mo>-</mo><mn mathvariant="normal">70</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="50pt" height="12pt" class="svg-formula" dspmath="mathimg" md5hash="b91ecb5e1d593155c8230c6eb959cf71"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="angeo-37-289-2019-ie00002.svg" width="50pt" height="12pt" src="angeo-37-289-2019-ie00002.png"/></svg:svg></span></span> km s<span class="inline-formula"><sup>−1</sup></span>. These two significant dipolarizations are accompanied
with the sharp increase in the energy flux of energetic electron inside
geosynchronous orbit. After a 5 min expansion
of the near-Earth plasma sheet (NEPS), THEMIS-E (TH-E) located outside geosynchronous orbit also detected this tailward expanding plasma sheet with ion flows of <span class="inline-formula">−</span>150 km s<span class="inline-formula"><sup>−1</sup></span>. The dipolarization propagates tailward
with a speed of <span class="inline-formula">−</span>47 km s<span class="inline-formula"><sup>−1</sup></span> along a 2.2 <span class="inline-formula"><i>R</i><sub>E</sub></span> distance in the
<span class="inline-formula"><i>X</i></span> direction between TH-D and TH-E within 5 min. These dipolarizations with tailward ion flows observed inside geosynchronous orbit indicate a new
energy transfer path in the inner magnetosphere during substorms.</p> |
| first_indexed | 2024-12-22T16:05:26Z |
| format | Article |
| id | doaj.art-bceaef7fdf3e4553b35b3c3fbe87d6f3 |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-12-22T16:05:26Z |
| publishDate | 2019-05-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-bceaef7fdf3e4553b35b3c3fbe87d6f32022-12-21T18:20:36ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762019-05-013728929710.5194/angeo-37-289-2019Magnetic dipolarizations inside geosynchronous orbit with tailward ion flowsX. Sun0X. Sun1W. W. Liu2S. Duan3State Key Laboratory of Space Weather, National Space Science Center (NSSC), Chinese Academy of Sciences (CAS), Beijing, 100190, ChinaUniversity of Chinese Academy of Sciences, Beijing, 100049, ChinaState Key Laboratory of Space Weather, National Space Science Center (NSSC), Chinese Academy of Sciences (CAS), Beijing, 100190, ChinaState Key Laboratory of Space Weather, National Space Science Center (NSSC), Chinese Academy of Sciences (CAS), Beijing, 100190, China<p>Electromagnetic field and plasma data from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) near-Earth probes are used to investigate magnetic dipolarizations inside geosynchronous orbit on 27 August 2014 during an intense substorm with <span class="inline-formula">AE<sub>max</sub>∼1000</span> nT. THEMIS-D (TH-D) was located inside geosynchronous orbit around midnight in the interval from 09:25 to 09:55 UT. During this period, two distinct magnetic dipolarizations with tailward ion flows are observed by TH-D. The first one is indicated by the magnetic elevation angle increase from 15 to 25<span class="inline-formula"><sup>∘</sup></span> around 09:30:40 UT. The tailward perpendicular velocity is <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow><msub><mi>V</mi><mrow><mo>⊥</mo><mi mathvariant="normal">x</mi></mrow></msub><mo>∼</mo><mo>-</mo><mn mathvariant="normal">50</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="50pt" height="12pt" class="svg-formula" dspmath="mathimg" md5hash="826bf632c156da00cbb31ba70094db72"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="angeo-37-289-2019-ie00001.svg" width="50pt" height="12pt" src="angeo-37-289-2019-ie00001.png"/></svg:svg></span></span> km s<span class="inline-formula"><sup>−1</sup></span>. The second one is presented by the elevation angle increase from 25 to 45<span class="inline-formula"><sup>∘</sup></span> around 09:36 UT, and the tailward perpendicular velocity is <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M6" display="inline" overflow="scroll" dspmath="mathml"><mrow><msub><mi>V</mi><mrow><mo>⊥</mo><mi mathvariant="normal">x</mi></mrow></msub><mo>∼</mo><mo>-</mo><mn mathvariant="normal">70</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="50pt" height="12pt" class="svg-formula" dspmath="mathimg" md5hash="b91ecb5e1d593155c8230c6eb959cf71"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="angeo-37-289-2019-ie00002.svg" width="50pt" height="12pt" src="angeo-37-289-2019-ie00002.png"/></svg:svg></span></span> km s<span class="inline-formula"><sup>−1</sup></span>. These two significant dipolarizations are accompanied with the sharp increase in the energy flux of energetic electron inside geosynchronous orbit. After a 5 min expansion of the near-Earth plasma sheet (NEPS), THEMIS-E (TH-E) located outside geosynchronous orbit also detected this tailward expanding plasma sheet with ion flows of <span class="inline-formula">−</span>150 km s<span class="inline-formula"><sup>−1</sup></span>. The dipolarization propagates tailward with a speed of <span class="inline-formula">−</span>47 km s<span class="inline-formula"><sup>−1</sup></span> along a 2.2 <span class="inline-formula"><i>R</i><sub>E</sub></span> distance in the <span class="inline-formula"><i>X</i></span> direction between TH-D and TH-E within 5 min. These dipolarizations with tailward ion flows observed inside geosynchronous orbit indicate a new energy transfer path in the inner magnetosphere during substorms.</p>https://www.ann-geophys.net/37/289/2019/angeo-37-289-2019.pdf |
| spellingShingle | X. Sun X. Sun W. W. Liu S. Duan Magnetic dipolarizations inside geosynchronous orbit with tailward ion flows Annales Geophysicae |
| title | Magnetic dipolarizations inside geosynchronous orbit with tailward ion flows |
| title_full | Magnetic dipolarizations inside geosynchronous orbit with tailward ion flows |
| title_fullStr | Magnetic dipolarizations inside geosynchronous orbit with tailward ion flows |
| title_full_unstemmed | Magnetic dipolarizations inside geosynchronous orbit with tailward ion flows |
| title_short | Magnetic dipolarizations inside geosynchronous orbit with tailward ion flows |
| title_sort | magnetic dipolarizations inside geosynchronous orbit with tailward ion flows |
| url | https://www.ann-geophys.net/37/289/2019/angeo-37-289-2019.pdf |
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