Non-Spiral Interplanetary Magnetic Field and Coronal Mass Ejections

非螺旋行星际磁场和日冕物质抛射

基本信息

批准号：
14540416
负责人：
NAKAGAWA Tomoko
金额：
$ 1.02万
依托单位：
Tohoku Intsitute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540416/
关键词：
CME acceleration of solar wind solar wind plasma IMF interplanetary space non-spiral field NOZOMI SOHO LASCO 「SOHO」衛星太陽風惑星空間磁場 ICME 太陽風の加速平面状磁場構造宇宙天気予報

项目摘要

The speeds of propagation of CMEs in interplanetary space are less distributed than their initial speeds measured on their departure from the limb of the Sun. Gopalswamy et al.(2000, 2001) presented a linear relationship between initial speeds of limb CMEs and their average acceleration during their travel time in interplanetary space. The linear relationship suggests that some dragging force is acting on CMEs. If similar relationship holds within 20 solar radii from the Sun, it would give information on the initial speed of 'ambient' solar wind in the vicinity of the Sun. The relationship between the initial acceleration and the initial speeds of limb CMEs was examined by using SOHO/LASCO CME Catalogue. For the cases for which correlation coefficient was fairly good (from -0.6 to -I), the 'ambient' solar wind speed within 20 solar radii was estimated to be 150 -570 km/s. It is somewhat slower than but close to the speeds of real solar wind measured in interplanetary space.Interplanetary counterparts of a halo CME which occurred on April 13, 1999, were observed by NOZOMI and ACE on April 16-18, when the two spacecraft were within 3 degrees in heliocentric longitude and 0.2 AU in heliocentric distance. The interplanetary magnetic fields had filamentary structures with large Bz components, and the Bz component was positive at NOZOMI while negative at ACE. Both magnetic fields were different from a magnetic cloud. It implies that the CME had a number of filamentary structures of magetic field lines with various directions. An interplanetary magnetic field of this kind can be used for detection of candidates of interplanetary counterparts of CMEs.

行星际空间中CME的传播速度的分布要比它们从太阳的肢体出发时所测得的初始速度少。 Gopalswamy等人（2000年，2001年）提出了肢体CME的初始速度与它们在行星际空间中旅行期间的平均加速度之间的线性关系。线性关系表明某些拖动力在CME上起作用。如果类似的关系在太阳的20个太阳半径范围内持有，它将提供有关太阳附近“环境”太阳风的初始速度的信息。使用SOHO/LASCO CME目录检查了初始加速度与肢体CME的初始速度之间的关系。对于相关系数的情况相当好（从-0.6到-i），估计在20个太阳半径内的“环境”太阳速度为150 -570 km/s。它比在空行间空间中测得的真实太阳风的速度慢。行星际磁场具有具有较大Bz成分的丝状结构，并且Bz成分在NOZOMI处为正，而ACE为负。两个磁场都与磁云不同。这意味着CME具有许多带有各个方向的Maget Field线的丝状结构。这种行星际磁场可用于检测CME的行星际对应物的候选物。