| Project/Area Number |
10640427
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Space and upper atmospheric physics
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| Research Institution | IBARAKI UNIVERSITY |
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Principal Investigator |
WATANABE Takashi IBARAKI Univ. Fuc. of Science, Professor, 理学部, 教授 (10023681)
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| Co-Investigator(Kenkyū-buntansha) |
NOZAWA Satoshi Ibaraki Univ. Fuc. of Science, Assistant, 理学部, 助手 (10261736)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1999: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1998: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | Solar Physics / CME / solar wind / interplanetary shock wave |
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| Research Abstract |
We examine three-dimensional propagation properties of CME-associated interplanetary disturbances observed in the ascending phase of the Solar Cycle 23 (1997-1998). Data sources are solar wind data obtained by spacecraft and IPS (interplanetary scintillation) observations. Interplanetary consequences of CMEs observed in early November 1997 are found to have similar configurations ; broad interplanetary disturbances with the local minimum of the propagation speed along the heliospheric current sheet, which was running near the ecliptic plane. This makes a clear contrast with interplanetary disturbances observed in April-May 1998, which are tend to be confined within the hemisphere where the relevant solar events take place. Principal conclusions are as follows :
(1) IPS observation is sensitive to interplanetary counterpart of bright (high-density?) portion of a CME.
(2) In very early stage of the Solar Cycle 23 (Nov. 1997), CMEs and associated interplanetary disturbances with the broad extent both in the longitude and the latitude were observed. The propagation speeds of these disturbances were generally low in the heliospheric current sheet which was located near the solar equatorial plane in this period.
(3) In 1998, the heliospheric current sheet started to make a large north-south excursion, and CMEs localized in either of the northern and the southern hemisphere were observed.
(4) Large and bright CMEs took place along the heliospheric current sheet.
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