How did the solar wind structure change around the solar maximum? From interplanetary scintillation observation
Observations from the second Ulysses fast latitude scan show that the global structure of solar wind near solar maximum is much more complex than at solar minimum. Soon after solar maximum, Ulysses observed a polar coronal hole (high speed) plasma with magnetic polarity of the new solar cycl...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2003-06-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/21/1257/2003/angeo-21-1257-2003.pdf |
| _version_ | 1818132243603783680 |
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| author | K. Fujiki M. Kojima M. Tokumaru T. Ohmi A. Yokobe A. Yokobe K. Hayashi D. J. McComas H. A. Elliott |
| author_facet | K. Fujiki M. Kojima M. Tokumaru T. Ohmi A. Yokobe A. Yokobe K. Hayashi D. J. McComas H. A. Elliott |
| author_sort | K. Fujiki |
| collection | DOAJ |
| description | Observations from the
second Ulysses fast latitude scan show that the global structure of solar wind
near solar maximum is much more complex than at solar minimum. Soon after solar
maximum, Ulysses observed a polar coronal hole (high speed) plasma with
magnetic polarity of the new solar cycle in the Northern Hemisphere. We analyze
the solar wind structure at and near solar maximum using interplanetary
scintillation (IPS) measurements. To do this, we have developed a new
tomographic technique, which improves our ability to examine the complex
structure of the solar wind at solar maximum. Our IPS results show that in 1999
and 2000 the total area with speed greater than 700 km s<sup>-1</sup> is
significantly reduced first in the Northern Hemisphere and then in the Southern
Hemisphere. For year 2001, we find that the formation of large areas of fast
solar wind around the north pole precedes the formation of large polar coronal
holes around the southern pole by several months. The IPS observations show a
high level agreement to the Ulysses observation, particularly in coronal holes.<br><br><b>Key words. </b>Interplanetary physics
(solar wind plasma) – Radio science (remote sensing) |
| first_indexed | 2024-12-11T08:33:44Z |
| format | Article |
| id | doaj.art-614272e875c845b6b3dae9d85fbd986f |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-12-11T08:33:44Z |
| publishDate | 2003-06-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-614272e875c845b6b3dae9d85fbd986f2022-12-22T01:14:24ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762003-06-01211257126110.5194/angeo-21-1257-2003How did the solar wind structure change around the solar maximum? From interplanetary scintillation observationK. Fujiki0M. Kojima1M. Tokumaru2T. Ohmi3A. Yokobe4A. Yokobe5K. Hayashi6D. J. McComas7H. A. Elliott8Solar-Terrestrial Environment Laboratory, Nagoya University, 3-13 Honohara, Toyokawa, Aichi, JapanSolar-Terrestrial Environment Laboratory, Nagoya University, 3-13 Honohara, Toyokawa, Aichi, JapanSolar-Terrestrial Environment Laboratory, Nagoya University, 3-13 Honohara, Toyokawa, Aichi, JapanSolar-Terrestrial Environment Laboratory, Nagoya University, 3-13 Honohara, Toyokawa, Aichi, JapanSGI Japan, Ltd., 4-20-3 Ebisu, Shinjuku, Tokyo, JapanSolar-Terrestrial Environment Laboratory, Nagoya University, 3-13 Honohara, Toyokawa, Aichi, JapanSolar-Terrestrial Environment Laboratory, Nagoya University, 3-13 Honohara, Toyokawa, Aichi, JapanSouthwest Research Institute, San Antonio, TX, USASouthwest Research Institute, San Antonio, TX, USAObservations from the second Ulysses fast latitude scan show that the global structure of solar wind near solar maximum is much more complex than at solar minimum. Soon after solar maximum, Ulysses observed a polar coronal hole (high speed) plasma with magnetic polarity of the new solar cycle in the Northern Hemisphere. We analyze the solar wind structure at and near solar maximum using interplanetary scintillation (IPS) measurements. To do this, we have developed a new tomographic technique, which improves our ability to examine the complex structure of the solar wind at solar maximum. Our IPS results show that in 1999 and 2000 the total area with speed greater than 700 km s<sup>-1</sup> is significantly reduced first in the Northern Hemisphere and then in the Southern Hemisphere. For year 2001, we find that the formation of large areas of fast solar wind around the north pole precedes the formation of large polar coronal holes around the southern pole by several months. The IPS observations show a high level agreement to the Ulysses observation, particularly in coronal holes.<br><br><b>Key words. </b>Interplanetary physics (solar wind plasma) – Radio science (remote sensing)https://www.ann-geophys.net/21/1257/2003/angeo-21-1257-2003.pdf |
| spellingShingle | K. Fujiki M. Kojima M. Tokumaru T. Ohmi A. Yokobe A. Yokobe K. Hayashi D. J. McComas H. A. Elliott How did the solar wind structure change around the solar maximum? From interplanetary scintillation observation Annales Geophysicae |
| title | How did the solar wind structure change around the solar maximum? From interplanetary scintillation observation |
| title_full | How did the solar wind structure change around the solar maximum? From interplanetary scintillation observation |
| title_fullStr | How did the solar wind structure change around the solar maximum? From interplanetary scintillation observation |
| title_full_unstemmed | How did the solar wind structure change around the solar maximum? From interplanetary scintillation observation |
| title_short | How did the solar wind structure change around the solar maximum? From interplanetary scintillation observation |
| title_sort | how did the solar wind structure change around the solar maximum from interplanetary scintillation observation |
| url | https://www.ann-geophys.net/21/1257/2003/angeo-21-1257-2003.pdf |
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