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Research on the Solar Corona and Ionosphere based on the Total Solar Eclipse on 11 Aug.1999

基于1999年8月11日日全食的日冕和电离层研究

基本信息

批准号：
11691140
负责人：
ICHIMOTO Kiyoshi
金额：
$ 6.46万
依托单位：
National Astronomical Observatory, Japan
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11691140/
关键词：
Sun Solar corona Total solar eclipse Ionosphere Solar wind Instrument for solar observation 太陽物理学分光観測

项目摘要

Three observation teams were dispatched for the total solar eclipse on 11 August 1999. Teams from the National Astronomical Observatory (NAOJ) and Kyoto University made experiments at Elasig in Turkey. NAOJ performed a spectroscopic observation of the corona on northern pole and obtained 8 fine spectra. They found that the electron temperature of the lower corona was about 2MK, which is significantly high compared with past measurements.Team of the Kyoto University took high resolution coronal images at three temperatures using a 15-cm refractor, 4 types of filters, and CCD camera with 4M pixels. They plan to study the coronal structures in wide temperature range (10^4K=5x10^6K) combining with the data from space observatories.Team of the Kyusyu University observed geomagnetic fields at 5 stations among Europe and southern Africa to investigate the effect of the asymmetric boundary condition for geomagnetic fields during the total solar eclipse. They found a variation of geomagnetic field only in northern hemisphere in which the shadow of the moon passed through, but no variation in southern hemisphere. This implies that there was a closed electric current system in the ionosphere and the effect did not propagate to another hemisphere, This discovery highlighted a new mechanism which inhibits a global current along geomagnetic fields. In 2000, a conference was held in Tokyo in which results from each experiments were presented and future plan of observing total eclipses were discussed extensively.

1999年8月11日，日本派遣了三个观测队观测日全食。国家天文台（NAOJ）和京都大学的观测队在土耳其的埃拉西格进行了实验。 NAOJ对北极日冕进行了光谱观测，获得了8张精细光谱。他们发现下日冕的电子温度约为2MK，与过去的测量相比明显偏高。京都大学团队使用15厘米折射镜、4种滤光片和400万像素的CCD相机在三个温度下拍摄了高分辨率日冕图像。他们计划结合空间观测站的数据，研究宽温度范围（10^4K=5x10^6K）的日冕结构。九州大学团队在欧洲和南部非洲的5个站观测了地磁场，以研究日全食期间地磁场不对称边界条件的影响。他们发现，只有月球阴影穿过的北半球地磁场发生了变化，而南半球则没有变化。这意味着电离层中存在一个封闭的电流系统，并且该效应不会传播到另一个半球。这一发现凸显了一种抑制沿着地磁场的全球电流的新机制。 2000年，在东京召开了一次会议，会上介绍了各个实验的结果，并广泛讨论了观测日全食的未来计划。