太阳物理研究组知识库

日冕物质抛射(CME)是由太阳磁场驱动向行星际空间喷射等离子体物质和磁场的大尺度太阳爆发活动,是灾害性空间天气事件最主要的驱动源之一。朝着地球方向爆发的CME极易到达地球并造成灾害性空间天气,因此研究这类CME对于空间天气预报与太阳物理研究具有极为重要的意义。随着观测技术的发展,CME的观测及预报和研究工作取得了长足的进展。但由于常规观测手段与预报方法的局限,对朝着地球爆发的CME进行准确有效预报的目标至今仍未能实现。首先阐述CME与空间天气的关系,强调对CME预报研究的重要性;然后介绍预报研究中CME/ICME复杂的动力学过程,讨论这些过程对CME预报可能产生的影响;接着,回顾CME的常规观测手段,并讨论观测手段存在的不足;第4章,介绍CME主要的预报方法,同时讨论预报工作中存在的困难;第5章,讨论太阳雷达主动探测技术在日冕探测与CME预报研究中的可能应用前景;最后,总结CME预报研究现状,对预报研究工作中重要的问题进行综述,展望太阳雷达的未来应用。

Coronal mass ejection (CME),  the large scale plasma structure driven by solar magnetic field into interplanetary space, is one of the most important drivers of the space weather. When the CME erupts toward the earth (the so-called halo CME) , the high temperature plasmas and magnetic structures inside the CME are very likely to impact the environment around the Earth, which causes the disastrous space weather. The paper introduces the relationship between CME/ICME and the space weather, discusses the negative effect on space and geomagnetic environment and emphasizes the importance and necessity of forecasting this solar activities and possible impacts on the space weather.First, CME deflection, rotation and interactions with the interplanetary medium observed from the sun to the place around 1AU are introduced and we point out that in the future forecast, these dynamical phenomena should be considered. Second, we discussed disadvantages of the coronagraph, in-situ satellite and radio observations in detecting the halo CME. When introducing empirical/statistical methods, dynamical method, numerical method and 3D reconstruction techniques for forecasting the halo CME, and the weakness of them appears. Considering these limitations to the existing techniques, we point out that new powerful solar observation techniques should be developed. As an active detection, solar radar may become the most promising method to detect the solar activities. We introduce the history and results of the ever-existing solar radar experiments, and discuss the advantages of solar radar in detecting and forecasting the halo CME. Finally, we summarize the weakness or disadvantages of the existing method in detecting the halo CME and in forecasting the disastrous space weather, and point out that solar radar, as an active technique,possible appear potential in achieving the goal of space weather forecasting.