| Project/Area Number |
15340162
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Space and upper atmospheric physics
|
|---|
| Research Institution | Nagoya University |
|---|
Principal Investigator |
KOJIMA Masayoshi Nagoya University, Solar-Terrestrial Environment Laboratory, Professor, 太陽地球環境研究所, 教授 (70023687)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TOKUMARU Munetoshi Nagoya University, Solar-Terrestrial Environment Laboratory, Associate Professor, 太陽地球環境研究所, 助教授 (60273207)
FUJIKI Kenichi Nagoya University, Solar-Terrestrial Environment Laboratory, Assistant Professor, 太陽地球環境研究所, 助手 (20303597)
HAKAMADA Kazuyuki Chubu University, College of Engineering, Professor, 工学部, 教授 (90102780)
|
|---|
| Project Period (FY) |
2003 – 2006
|
| Project Status |
Completed (Fiscal Year 2006)
|
| Budget Amount *help |
¥16,100,000 (Direct Cost: ¥16,100,000)
Fiscal Year 2006: ¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2005: ¥4,100,000 (Direct Cost: ¥4,100,000)
Fiscal Year 2004: ¥4,000,000 (Direct Cost: ¥4,000,000)
Fiscal Year 2003: ¥4,300,000 (Direct Cost: ¥4,300,000)
|
|---|
| Keywords | interplanetary science / radio astronomy / solar wind / solar wind acceleration / CME / 宇宙空間 / 電波天文学 / 電波観測 / 加速機構 / 惑星間空間プラズマ / 惑星間空間衝撃波 |
|---|
| Research Abstract |
(1) Observational study of solar wind acceleration
One of main topics of solar wind research is a mechanism of solar wind acceleration. We found positive correlation between V and B/fin our previous work, where Vis solar wind velocity observed with IPS, B is photospheric magnetic field strength, and f is flux expansion rate. To check this relation through solar cycle, we analyzed the relation between solar wind velocity and magnetic properties of its photospheric sources during years from 1995 to 2005. Solar wind velocity observed with IPS are mapped back to source surface by using constant velocity ballistic model, and then, the photospheric solar wind sources are determined by using potential field calculation of coronal magnetic field from synoptic maps observed at Kitt Peak National Solar Observatory. Potential magnetic field line is traced down from source surface (1×1° grid) to photosphere, then flux expansion rate is calculated by taking ratio of magnetic field strengths at source surface (B_<SS>) and photosphere, f=B_<ph>/(B_<SS>R^2_<SS>), where R_<SS> is a distance of source surface from the Sun center (2.5 solar radii). The relation between solar wind velocity, magnetic flux expansion rate and photospheric magnetic field are examined by cross-correlation analysis. As a result, we found positive correlation between V and B/f during period from solar minimum to solar maximum.
(2) Structure of interplanetary shock and its propagation property
We reconstructed the 3-dimensional distribution of solar wind disturbances from STEL IPS observation for several CME events successfully by using model fitting analysis. We compared some of these events to observations with Solar Mass Ejection Imager (SMIE) satellite. As results, the structures reconstructed from IPS data were found to be consistent with solar wind density distribution determined from Solar Mass Ejection Imager (SMEI) observations.
|
